Jun-Feng Bai

Fine Tuning of MOF-505 Analogues To Reduce Low-Pressure Methane Uptake and Enhance Methane Working Capacity

Co-reporter:Dr. Mingxing Zhang;Dr. Wei Zhou;Dr. Tony Pham;Katherine A. Forrest; Dr. Wenlong Liu;Dr. Yabing He;Dr. Hui Wu;Dr. Taner Yildirim; Dr. Banglin Chen; Dr. Brian Space; Dr. Yi Pan; Dr. Michael J. Zaworotko; Dr. Junfeng Bai

Angewandte Chemie 2017 Volume 129(Issue 38) pp:11584-11588

Publication Date(Web):2017/09/11

DOI:10.1002/ange.201704974

AbstractWe present a crystal engineering strategy to fine tune the pore chemistry and CH4-storage performance of a family of isomorphic MOFs based upon PCN-14. These MOFs exhibit similar pore size, pore surface, and surface area (around 3000 m2 g−1) and were prepared with the goal to enhance CH4 working capacity. [Cu2(L2)(H2O)2]n (NJU-Bai 41: NJU-Bai for Nanjing University Bai's group), [Cu2(L3)(H2O)2]n (NJU-Bai 42), and [Cu2(L4)(DMF)2]n (NJU-Bai 43) were prepared and we observed that the CH4 volumetric working capacity and volumetric uptake values are influenced by subtle changes in structure and chemistry. In particular, the CH4 working capacity of NJU-Bai 43 reaches 198 cm3 (STP: 273.15 K, 1 atm) cm−3 at 298 K and 65 bar, which is amongst the highest reported for MOFs under these conditions and is much higher than the corresponding value for PCN-14 (157 cm3 (STP) cm−3).

A copper-organic framework as scavenger towards organic dyes pollutants via physical adsorption and visible-light photodegradation

Co-reporter:Qing Li, Dong-Xu Xue, Yu-Feng Zhang, Zong-Hui Zhang, Qian Wang, Ziwei Gao, Junfeng Bai

Inorganic Chemistry Communications 2017 Volume 85(Volume 85) pp:

Publication Date(Web):1 November 2017

DOI:10.1016/j.inoche.2017.06.021

A 2-periodic copper–organic framework of 1 has been deliberately obtained via solvothermal reaction between Cu(NO3)2·3H2O and a V-shaped highly conjugated organic linker. Single-crystal X-ray structural analyses reveal that 1 displays a 3D stacking structure along with channel-typed interior architectures decorated with amino and trifluoromethoxy functionalized groups. 1 demonstrates not only notably selective encapsulation of small-sized MB and MO molecules with high adsorption rate, but also efficient photodegradation activities through decomposing MB, MO and large-sized phthalocyanine of reactive blue 21 under visible light irradiation.Solvothermal reaction between Cu(NO3)2·3H2O and a V-shaped highly conjugated organic linker, a 2-periodic copper–organic framework of 1 has been deliberately obtained. Due to its uniquely architectural features, 1 demonstrates not only notably selective encapsulation of small-sized MB and MO dye molecules with high adsorption rate, but also efficient photodegradation activities through decomposing dyes of MB, MO and bulky phthalocyanine of reactive blue 21 under visible light irradiation.Download high-res image (447KB)Download full-size image

A (3,6)-Connected Metal–Organic Framework with pyr Topology and Highly Selective CO2 Adsorption

Co-reporter:Qian Wang, Jingjing Jiang, Mingxing Zhang, and Junfeng Bai

Crystal Growth & Design 2017 Volume 17(Issue 1) pp:

Publication Date(Web):December 16, 2016

DOI:10.1021/acs.cgd.6b01484

Upon the basis of a bifunctional organic ligand with two carboxyl groups and one N donor, 5-(quinolin-4-yl)isophthalic acid (H2L), a new (3,6)-connected metal–organic framework with pyr topology, [Cu(L)·DMF]n (NJU-Bai32), has been synthesized and exhibits highly selective CO2 adsorption.

Finely tuning MOFs towards high performance in C2H2 storage: synthesis and properties of a new MOF-505 analogue with an inserted amide functional group

Co-reporter:Mingxing Zhang, Bin Li, Yunzhi Li, Qian Wang, Wenwei Zhang, Banglin Chen, Shuhua Li, Yi Pan, Xiaozeng You and Junfeng Bai

Chemical Communications 2016 vol. 52(Issue 45) pp:7241-7244

Publication Date(Web):04 May 2016

DOI:10.1039/C6CC03198F

Aiming to improve the acetylene (C2H2) storage capability of MOFs, we successfully designed NJU-Bai 17, a new analogue of MOF-505 with an inserted amide functional group which exhibits almost record high C2H2 uptakes of 222.4 cm3 g−1 at 296 K and 296 cm3 g−1 at 273 K under 1 bar. This result has been further supported by the determination of the heat of C2H2 adsorption and Grand Canonical Monte Carlo (GCMC) and first-principle calculations.

Finely tuning MOFs towards high-performance post-combustion CO2 capture materials

Co-reporter:Qian Wang, Junfeng Bai, Zhiyong Lu, Yi Pan and Xiaozeng You

Chemical Communications 2016 vol. 52(Issue 3) pp:443-452

Publication Date(Web):15 Oct 2015

DOI:10.1039/C5CC07751F

CO2 capture science and technology, particularly for the post-combustion CO2 capture, has become one of very important research fields, due to great concern of global warming. Metal–organic frameworks (MOFs) with a unique feature of structural fine-tunability, unlike the traditional porous solid materials, can provide many and powerful platforms to explore high-performance adsorbents for post-combustion CO2 capture. Until now, several strategies for finely tuning MOF structures have been developed, in which either the larger quadrupole moment and polarizability of CO2 are considered: metal ion change (I), functional groups attachment (II) and functional group insertion (III), vary the electronic nature of the pore surface; or targeting the smaller kinetic diameter of CO2 over N2 is focused on: framework interpenetration (IV), ligand shortening (V) and coordination site shifting (VI) contract the pore size of frameworks to improve their CO2 capture properties. In this review, from the viewpoint of synthetic materials scientists/chemists, we would like to introduce and summarize these strategies based upon recent work published by other groups and ourselves.

Functionalization of Microporous Lanthanide-Based Metal–Organic Frameworks by Dicarboxylate Ligands with Methyl-Substituted Thieno[2,3-b]thiophene Groups: Sensing Activities and Magnetic Properties

Co-reporter:Suna Wang, Tingting Cao, Hui Yan, Yunwu Li, Jing Lu, Ranran Ma, Dacheng Li, Jianmin Dou, and Junfeng Bai

Inorganic Chemistry 2016 Volume 55(Issue 11) pp:5139-5151

Publication Date(Web):May 11, 2016

DOI:10.1021/acs.inorgchem.5b02801

From a methyl-substituted thieno[2,3-b]thiophene dicarboxylate, three types of three-dimensional (3-D) microporous lanthanide-based metal–organic frameworks, {[Ln(DMTDC)1.5(H2O)2]·DEF}n (type I, Ln = Eu 1, Tb 2), {[Ln(DMTDC)1.5(H2O)2]·0.5DMF·0.5H2O}n (type II, Ln = Gd 3, Dy 4, Er 5), and {[Ln4(DMTDC)6(DMF)2]·0.5DMF·1.5H2O}n (type III, Ln = Er 6) (H2DMTDC = 3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid, DEF = N,N′-diethylformamide, DMF = N,N′-dimethylformamide), have been solventhermally synthesized. Types I and II are isostructural, which exhibit 1-D triangular channels constructed by double-stranded rod-shaped {Ln(CO2)2}n chains. Type III demonstrates an intriguing framework with triple-stranded rod-shaped {Ln(CO2)3}n chains arranged along the (1,1,0) and (1,–1,0) axes and possesses two kinds of triangular channels along two axes, respectively. Immobilization of the Lewis basic sites of thiophene groups induced gas adsorption and sensing properties into these microporous frameworks. Complexes 5(Er) and 6(Er) display moderate adsorption properties toward N2 and CO2, and the Qst of CO2 are as high as 36.3 and 34.8 kJ mol–1, respectively. Complexes 1(Eu) and 2(Tb) exhibit sensing properties toward nitrobenzene, acetone, and the Cu2+ ion in both DMF and aqueous solution. Complex 3(Gd) shows a significant magnetocaloric effect with ΔSm = 24.3 J·kg–1·K–1 at 3.0 K and 7 T. Complex 4(Dy) exhibits slow magnetic relaxation with the energy barrier Δ/kB of 48.29 K.

Two New (3,6)-Connected MOFs with eea Topology and High CH4 Uptake

Co-reporter:Qian Wang, Xiaohui Song, Mingxing Zhang, Wenlong Liu, and Junfeng Bai

Crystal Growth & Design 2016 Volume 16(Issue 11) pp:6156

Publication Date(Web):October 6, 2016

DOI:10.1021/acs.cgd.6b01265

Two new (3,6)-connected and eea topological MOFs without open metal sites, NJU-Bai30 and NJU-Bai31, from Cu-paddelwheel units and 5-[4′-(pyridin-4-yl)phenyl]isophthalic acid (L1) and 5-[3′-amino-4′-(pyridin-4-yl)phenyl]isophthalic acid (L2) have been synthesized, and interestingly, they exhibit relatively high surface area and large CH4 adsorption uptake.

The Utilization of Amide Groups To Expand and Functionalize MetalOrganic Frameworks Simultaneously

Co-reporter:Dr. Zhiyong Lu;Dr. Junfeng Bai;Cheng Hang;Fei Meng;Dr. Wenlong Liu;Dr. Yi Pan;Dr. Xiaozeng You

Chemistry - A European Journal 2016 Volume 22( Issue 18) pp:6277-6285

Publication Date(Web):

DOI:10.1002/chem.201504907

Abstract

A new stepwise ligand-elongation strategy by amide spacers is utilized to prepare isoreticularly high-porous metal–organic frameworks (MOFs), namely, quasi-mesoporous [Cu₂(PDBAD)(H₂O)]_n (H₄PDBAD=5,5′-((4,4′-((pyridine-3,5-dicarbonyl)bis(azanediyl))bis(benzoyl))bis(azanediyl))diisophthalic acid; NJU-Bai22: NJU-Bai for Nanjing University Bai's group), and mesoporous [Cu₂(PABAD)(H₂O)]_n (H₄PABAD=5,5′-((4,4′-((4,4′-((pyridine-3,5-dicarbonyl)bis(azanediyl))bis(benzoyl))bis (azanediyl))bis(benzoyl))bis(azanediyl))diisophthalic acid; NJU-Bai23). Compared with the prototypical MOF of [Cu₂(PDAD)(H₂O)]_n (H₄PDAD=5,5′-(pyridine-3,5-dicarbonyl)bis(azanediyl)diisophthalic acid; NJU-Bai21, also termed as PCN-124), both MOFs exhibit almost the same CO₂ adsorption enthalpy and CO₂ selectivity values, and better capacity for CO₂ storage under high pressure; these results make them promising candidate materials for CO₂ capture and sequestration. Interestingly, this new method, in comparison with traditional strategies of using phenyl or triple-bond spacers, is easier and cheaper, resulting in a better ability to retain high CO₂ affinity and selectivity in MOFs with large pores and high CO₂ storage capacity. Additionally, it may lead to the high thermal stability of the MOFs and also their tolerance to water, which is related to the balance between the density of functional groups and pore sizes. Therefore, this strategy could provide new opportunities to explore more functionalized mesoporous MOFs with high performance.

The Utilization of Amide Groups to Expand and Functionalize Metal-Organic Frameworks Simultaneously

Co-reporter:Dr. Zhiyong Lu;Dr. Junfeng Bai;Cheng Hang;Fei Meng;Dr. Wenlong Liu;Dr. Yi Pan;Dr. Xiaozeng You

Chemistry - A European Journal 2016 Volume 22( Issue 18) pp:

Publication Date(Web):

DOI:10.1002/chem.201601034

Abstract

Invited for the cover of this issue is the group of Junfeng Bai at Nanjing University. The image depicts how to obtain mesoporosity in MOFs by ligand extension with amide spacers. Read the full text of the article at 10.1002/chem.201504907.

Cover Picture: The Utilization of Amide Groups To Expand and Functionalize MetalOrganic Frameworks Simultaneously (Chem. Eur. J. 18/2016)

Co-reporter:Dr. Zhiyong Lu;Dr. Junfeng Bai;Cheng Hang;Fei Meng;Dr. Wenlong Liu;Dr. Yi Pan;Dr. Xiaozeng You

Chemistry - A European Journal 2016 Volume 22( Issue 18) pp:

Publication Date(Web):

DOI:10.1002/chem.201601009

Solvent- and metal-directed lanthanide-organic frameworks based on pamoic acid: observation of slow magnetization relaxation, magnetocaloric effect and luminescent sensing

Co-reporter:Suna Wang;Ranran Ma;Zhiwei Chen;Yunwu Li;Tingting Cao

Science China Chemistry 2016 Volume 59( Issue 8) pp:948-958

Publication Date(Web):2016 August

DOI:10.1007/s11426-015-0537-6

Two types of lanthanide coordination polymers, namely, [Ln(PA)(NO3)(DMA)3]n (Ln=Gd (1), Dy (2), Eu (3), Tb (4)) (type I), and {[Ln2(PA)3(DMF)4]·2DMF} (Ln=Eu (5), Tb (6)) (type II) (PA=Pamoic acid, DMA=dimethylacetamide, DMF=N,N-dimethylformamide), have been synthesized by the reaction of Ln(NO3)3·6H2O with pamoic acid through layer diffusion method. These complexes were characterized by single crystal X-ray diffraction, infrared spectroscopy (IR), thermogravimetric analysis (TGA), fluorescence and magnetic measurements. Solvents and lanthanide atoms in the reaction play an important role in controlling different structures. Type I demonstrated 1-D linear chain structure connected by Ln atoms and PA ligands. Type II exhibited non-interpenetrating 3-D 6-connected 43612 nets based on binuclear [Ln2(CO2)6(DMF)4] cores. Magnetic properties of complexes 1–4 were investigated in details. Complex 1 shows significant magnetocaloric effect with–ΔSm=20.37 J kg–1 K–1 at 3.0 K and 7 T. Complex 2 exhibits slow relaxation of the magnetization. Complexes 3–6 exhibit both ligand- and metal-centered fluorescent properties. Complex 6 demonstrates fluorescent sensing of DMF and Cu2+ ion.

Assembly of a series of d10 coordination polymers of pamoic acid through a mixed-ligand synthetic strategy: syntheses, structures and fluorescence properties

Co-reporter:Tingting Cao, Yanqiang Peng, Ting Liu, Suna Wang, Jianmin Dou, Yunwu Li, Changhui Zhou, Dacheng Li and Junfeng Bai

CrystEngComm 2014 vol. 16(Issue 46) pp:10658-10673

Publication Date(Web):22 Sep 2014

DOI:10.1039/C4CE01356E

Eight mixed-ligand coordination compounds, [Zn(PA)(bpp)]n (1), {[Cd(PA)2(Hbpp)2(H2O)2]·2H2O}n (2), [Zn(PA)(bbi)]n (3), [Cd(PA)(bbi)(H2O)]n (4), {[Cd3(PA)2(bbi)3(Cl)2]}n (5), {[Zn6(PA)5(datrz)2(Hdatrz)2(H2O)2]·16DMF}n (6), [Cd2(PA)(datrz)2(DMF)2]n (7), and {[Cd2(PA)2(bix)2(DMF)2]·4DMF}n (8) (bpp = 1,3-bi(4-pyridyl)propane, bbi = 1,4-bis(imidazol-1-yl)butane, H2datrz = 3,5-diamino-1,2,4-triazole, bix = 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized through the reaction of zinc and cadmium salts with pamoic acid (H2PA) and different N-donor ligands. The assembly of the ligands in different coordination modes and conformations leads to fascinating structures. 1 and 3 afford an interpenetrating polythreaded 2D → 3D motif composed of 44 sql undulated sheets, while right- and left-helices are alternatively arranged in 3. 2 possesses an interesting 3-D supramolecular network with 1-D hydrogen-bonded chains spanning different directions. 4 and 5 display both polyrotaxane and polycatenane characteristics. In 4, two 2,4-connected (4·85) nets interlocked with each other, forming a 2D → 2D polycatenating network. 5 exhibits a twofold interpenetrated (3,5,6)-connected (3·5·6)(3·52·67)(32·54·66·72·9) topology. 6 and 7 represent rare pentanodal (3,4)-connected and binodal (3,4)-connected frameworks with topologies of (4·5·6)(4·8·10)(52·6·8·9·11)(4·5·6·8·92)(4·5·7) and (4·6·8)(4·62·83), respectively. 8 displays 3-fold interpenetrated 4-connected SrAl2 topology with flexible bix ligands bridging Cd centers to form right- and left-helices. The mixed-ligand effect of the conformations of the PA ligand and N-heterocyclic coligands as well as the metal centers on the assembly of frameworks is unravelled in detail. Solid-state luminescence properties of all compounds were reported as well. Moreover, fluorescence properties of compounds 6 and 8 in various solvent suspensions at room temperature have also been investigated.

A nitro-decorated NbO-type metal–organic framework with a highly selective CO2 uptake and CH4 storage capacity

Co-reporter:Mingxing Zhang, Qian Wang, Zhiyong Lu, Huiyan Liu, Wenlong Liu and Junfeng Bai

CrystEngComm 2014 vol. 16(Issue 28) pp:6287-6290

Publication Date(Web):13 Mar 2014

DOI:10.1039/C4CE00202D

A nitro-decorated NbO-type metal–organic framework, Cu2NTPTB (NJU-Bai 14; H4NTPTB = 2′-nitro-[1,1′:4′,1′′-terphenyl]-3,3′′,5,5′′-tetracarboxylic acid), was synthesized and structurally characterized. It exhibited high permanent porosity with a BET surface area of 2384 m2 g−1, improved adsorption selectivity of CO2/CH4 (6.5) and CO2/N2 (20.8) at 298 K and 1 bar, high excess unsaturation CO2 uptake (94.0 wt%) at 273 K and 20 bar, and high methane total uptake of 184 cm3 cm−3 at 290 K and 35 bar.

Construction of Zn(II) microporous metal–organic frameworks based on 1,1′-ethynebenzene-3,3′,5,5′-tetracarboxylate

Co-reporter:Yun-Xia Hu, Yan-Tao Qian, Wen-Wei Zhang, Yi-Zhi Li, Jun-Feng Bai

Inorganic Chemistry Communications 2014 Volume 47() pp:102-107

Publication Date(Web):September 2014

DOI:10.1016/j.inoche.2014.07.025

•Three zinc MOFs based on H4EBTC with/without an auxiliary ligand are synthesized.•Zn(II) ions and carboxylates in different MOFs show different coordination modes.•The three MOFs are 3D microporous coordination polymers with intriguing topologies.•MOFs 1 and 3 exhibit good photoluminescence around the blue-violet region.Three novel microporous zinc MOFs, [Zn3(EBTC)2]∙2(CH3)2NH2∙ 0.5DMSO∙3H2O (1), [Zn(EBTC)0.5(BPY)]∙2DMSO∙0.5DMF∙2H2O (2) and [Zn2(EBTC)(BPP)2]∙3DMSO∙2DMF∙5H2O (3) (EBTC = 1,1′-ethynebenzene-3,3′,5,5′-tetracarboxylate, BPY = 4,4′-bipyridine, BPP = 1,3-bi(4-pyridyl)propane), have been synthesized under solvothermal conditions. The versatile coordination modes of EBTC are the key to such diverse MOFs. The results of X-ray single diffraction analyses indicate that 3D microporous MOF 1 with fla topology possesses 2D [Zn3(EBTC)2]∞ layer built from 1D double-chain-like motif containing trinuclear [Zn3(COO)8]2 − SBUs, in which the two phenyls of EBTC are almost perpendicularly arranged. Compound 2 is a 3D layer-pillar structure with Zn(II) ions bridged by planar EBTC to generate 2D [Zn(EBTC)0.5]∞ sheet, and the 2D sheets are further pillared by rigid BPY to form a 3D porous framework with fsc topology. Complex 3 exhibits a 3D 2-fold interpenetrating framework with (4.64.8)2(42.64) topology, in which the flexible BPP links the 1D [Zn2(EBTC)]∞ ladder to form a 2D [Zn2(EBTC)(BPP)2]∞ structure with large 1D channels, which leads the flexible 2D framework to 2-fold interpenetration and forms a 3D porous network. Complexes 1 and 3 exhibit good luminescent properties around the blue-violet region.Three novel zinc microporous MOFs with intriguing topologies have been synthesized by the self-assembly of H4EBTC with/without the corresponding auxiliary ligand of BPY/BPP, where Zn(II) modulates its coordination geometry from octahedron and tetragonal pyramid (1), trigonal bipyramid (2) to tetrahedron coordination (3) geometry as the carboxylates in EBTC adopt different coordination modes to meet the coordination requirement of the MOFs' rigidity/flexibility. MOFs 1 and 3 exhibit good photoluminescence around the blue-violet region.

Expanded Porous MOF-505 Analogue Exhibiting Large Hydrogen Storage Capacity and Selective Carbon Dioxide Adsorption

Co-reporter:Baishu Zheng, Ruirui Yun, Junfeng Bai, Zhiyong Lu, Liting Du, and Yizhi Li

Inorganic Chemistry 2013 Volume 52(Issue 6) pp:2823-2829

Publication Date(Web):March 4, 2013

DOI:10.1021/ic301598n

An expanded 4,4-paddlewheel-connected porous MOF-505-type metal–organic framework (MOF), [Cu2(PDEB)(H2O)2]·xS (NJU-Bai12; NJU-Bai represents the Nanjing University Bai group and S represents noncoordinated solvent molecules) has been designed from a nanosized rectangular diisophthalate linker containing alkyne groups 5,5′-(1,4-phenylenedi-2,1-ethynediyl)bis(1,3-benzenecarboxylic acid). This MOF material possesses permanent microporosity with the highest Brunauer–Emmett–Teller surface area of 3038 m2·g–1 and the largest unsaturated total hydrogen storage capacity of 62.7 mg·g–1 at 77 K and 20 bar among reported MOF-505 analogues. Additionally, NJU-Bai12 also exhibits excellent carbon dioxide (CO2) uptake capacity (23.83 and 19.85 mmol·g–1 at 20 bar for 273 and 298 K, respectively) and selective gas adsorption properties with CO2/CH4 selectivity of 5.0 and CO2/N2 selectivity of 24.6 at room temperature.

Fusing High Symmetric Coordination Polyhedrons of Cu6(PIP)4, Cu12(PIP)8, and Cu12(PIP)24 into an Unprecedented Porous MOF: Synthesis, Structure, and Its Remarkable CO2 Selectivity

Co-reporter:Ruirui Yun, Jingui Duan, Junfeng Bai, and Yizhi Li

Crystal Growth & Design 2013 Volume 13(Issue 1) pp:24-26

Publication Date(Web):December 3, 2012

DOI:10.1021/cg301577a

An unprecedented metal–organic framework, NJU-Bai6, formed by piling up the nanocages Cu6(PIP)4, Cu12(PIP)8, and Cu12(PIP)24 through sharing faces of the “opened” triangular and square windows, has been designed and structurally characterized. Very interestingly, it exhibits the third highest selectivity of CO2 over N2 with the value about 60 at room temperature.

High H2 and CH4 Adsorption Capacity of a Highly Porous (2,3,4)-Connected Metal–Organic Framework

Co-reporter:Zhiyong Lu, Liting Du, Kuanzhen Tang, and Junfeng Bai

Crystal Growth & Design 2013 Volume 13(Issue 6) pp:2252-2255

Publication Date(Web):May 7, 2013

DOI:10.1021/cg400449c

A porous metal–organic framework [Cu6(BDPP)3(H2O)6] (BDPP = 3,5-bis(3,5-dicarboxylphenyl)-pyridine) (NJU-Bai10) was synthesized. NJU-Bai10 exhibits a high BET surface area of 2883 m2 g–1, the highest excess H2 volumetric adsorption of 48.0 g L–1 (60 bar, 77 K), and a high methane uptake of 198.6 cm3 cm–3 that surpasses the DOE target.

Porous NbO-type metal–organic framework with inserted acylamide groups exhibiting highly selective CO2 capture

Co-reporter:Baishu Zheng, Heting Liu, Zhaoxu Wang, Xianyong Yu, Pinggui Yi and Junfeng Bai

CrystEngComm 2013 vol. 15(Issue 18) pp:3517-3520

Publication Date(Web):16 Jan 2013

DOI:10.1039/C3CE26177H

A new expanded microporous NbO-type metal–organic framework [Cu2(BDPT4−)]n with inserted acylamide groups has been designed and synthesized, which shows both a large CO2-uptake capacity (156.4 cm3 g−1 at 1 bar) and a high selectivity for CO2 over N2 (39.8) and CH4 (7.2) at 273 K.

Positional isomeric and substituent effect on the assemblies of a series of d10 coordination polymers based upon unsymmetric tricarboxylate acids and nitrogen-containing ligands

Co-reporter:Ting Liu, Suna Wang, Jing Lu, Jianmin Dou, Meiju Niu, Dacheng Li and Junfeng Bai

CrystEngComm 2013 vol. 15(Issue 27) pp:5476-5489

Publication Date(Web):02 May 2013

DOI:10.1039/C3CE40583D

Seven novel compounds, {[Zn2(L1)2]·2H2N(CH3)2·DMF}n (1), {[Cd2(L1)2]·2H2N(CH3)2·DMF}n (2), [Zn(HL2)(bpe)]n (3), [Zn2(HL2)2(bpea)2(H2O)]n (4), {[Cd2(HL2)2(bpe)(H2O)2]·2H2O}n (5), {[Cd2(HL2)2(bpea)(H2O)2]·2H2O}n (6) and {[Zn(HL3)(bpea)]·2H2O}n (7), were constructed based on three unsymmetrical tricarboxylate ligands and nitrogen-containing ligands (H3L1 = biphenyl-3,4′,5-tricarboxylic acid, H3L2 = biphenyl-3,3′,5-tricarboxylic acid, H3L3 = biphenyl-3-nitro-5,3′,5′-tricarboxylic acid, bpe = 1,2-bi(4-pyridyl)ethylene, bpea = 1,2-bi(4-pyridyl)ethane) under hydrothermal conditions. The positional isomeric and substituent effects of these ligands lead to fascinating structures. Compounds 1 and 2 afford 3D (3,6)-connected (4.62)2(42.610.83) rutile topologies based on dinuclear M2(CO2)2 SBUs. Compounds 3 and 4 are 4-connected diamondoid nets, which exhibit unusual roto-translational [2 + 2]-fold and common 4-fold interpenetration due to the different weak interactions among each interpenetrating motif, respectively. Compounds 5 and 6 are isostructural, both presenting 2D unique undulated (3,4)-connected (42.6)(42.63.8) topologies. Compound 7 possesses a 2D → 3D parallel polycatenation framework composed of (4,4) undulated sheets. The effects of the positions of the carboxylate groups and the substituent groups on the aromatic rings, the flexibility of the N-containing coligands as well as the coordination geometry of the metal centers are discussed in details. The fluorescence properties and thermal stability of the ligands and compounds have also been performed.

A highly porous agw-type metal–organic framework and its CO2 and H2 adsorption capacity

Co-reporter:Zhiyong Lu, Liting Du, Baishu Zheng, Junfeng Bai, Mingxing Zhang and Ruirui Yun

CrystEngComm 2013 vol. 15(Issue 45) pp:9348-9351

Publication Date(Web):15 Aug 2013

DOI:10.1039/C3CE41119B

An unsymmetrical tricarboxylate ligand with linking alkyne moiety has been used to construct a highly porous metal–organic framework with agw topology. The obtained Cu(II) MOF exhibits a high BET surface area of 3337.0 m2 g−1, a large capacity of CO2 (21.2 mmol g−1 at 298 K and 20 bar) and a good H2 adsorption (5.8 wt% at 77 K and 20 bar).

Formation of a MetalOrganic Framework with High Surface Area and Gas Uptake by Breaking Edges Off Truncated Cuboctahedral Cages

Co-reporter:Ruirui Yun;Zhiyong Lu; Yi Pan; Xiaozeng You ; Junfeng Bai

Angewandte Chemie International Edition 2013 Volume 52( Issue 43) pp:11282-11285

Publication Date(Web):

DOI:10.1002/anie.201302715

Formation of a MetalOrganic Framework with High Surface Area and Gas Uptake by Breaking Edges Off Truncated Cuboctahedral Cages

Co-reporter:Ruirui Yun;Zhiyong Lu; Yi Pan; Xiaozeng You ; Junfeng Bai

Angewandte Chemie 2013 Volume 125( Issue 43) pp:11492-11495

Publication Date(Web):

DOI:10.1002/ange.201302715

Fine-Tuning Pore Size by Shifting Coordination Sites of Ligands and Surface Polarization of Metal–Organic Frameworks To Sharply Enhance the Selectivity for CO2

Co-reporter:Liting Du ; Zhiyong Lu ; Kaiyuan Zheng ; Junyi Wang ; Xin Zheng ; Yi Pan ; Xiaozeng You ;Junfeng Bai

Journal of the American Chemical Society 2012 Volume 135(Issue 2) pp:562-565

Publication Date(Web):December 26, 2012

DOI:10.1021/ja309992a

Based upon the (3,6)-connected metal–organic framework {Cu(L1)·2H2O·1.5DMF}∞ (L1 = 5-(pyridin-4-yl)isophthalic acid) (SYSU, for Sun Yat-Sen University), iso-reticular {Cu(L2)·DMF}∞ (L2 = 5-(pyridin-3-yl)isophthalic acid) (NJU-Bai7; NJU-Bai for Nanjing University Bai group) and {Cu(L3)·DMF·H2O}∞ (L3 = 5-(pyrimidin-5-yl)isophthalic acid) (NJU-Bai8) were designed by shifting the coordination sites of ligands to fine-tune pore size and polarizing the inner surface with uncoordinated nitrogen atoms, respectively, with almost no changes in surface area or porosity. Compared with those of the prototype SYSU, both the adsorption enthalpy and selectivity of CO2 for NJU-Bai7 and NJU-Bai8 have been greatly enhanced, which makes NJU-Bai7 and NJU-Bai8 good candidates for postcombustion CO2 capture. Notably, the CO2 adsorption enthalpy of NJU-Bai7 is the highest reported so far among the MOFs without any polarizing functional groups or open metal sites. Meanwhile, NJU-Bai8 exhibits high uptake of CO2 and good CO2/CH4 selectivity at high pressure, which are quite valuable characteristics in the purification of natural gases.

High and selective CO2 capture by two mesoporous acylamide-functionalized rht-type metal–organic frameworks

Co-reporter:Baishu Zheng, Zhen Yang, Junfeng Bai, Yizhi Li and Shuhua Li

Chemical Communications 2012 vol. 48(Issue 56) pp:7025-7027

Publication Date(Web):20 Jan 2012

DOI:10.1039/C2CC17593B

Two mesoporous and flexible acylamide-functionalized rht-type MOFs exhibit not only high excess unsaturation CO2 uptake (157 wt%) at 20 bar and 273 K, but also good selectivity of CO2/CH4 (8.6) and CO2/N2 (34.3). The advantages of acylamide groups for CO2 capture have been further confirmed by GCMC and first-principles calculations.

Highly selective CO2 capture of an agw-type metal–organic framework with inserted amides: experimental and theoretical studies

Co-reporter:Jingui Duan, Zhen Yang, Junfeng Bai, Baishu Zheng, Yizhi Li and Shuhua Li

Chemical Communications 2012 vol. 48(Issue 25) pp:3058-3060

Publication Date(Web):12 Dec 2011

DOI:10.1039/C2CC16231H

An amide-inserted metal–organic framework (NJU-Bai3) presents high storage and high selectivity toward CO2 and combines these two interesting characters which strongly support our expectation that amide groups can significantly enhance the CO2 binding ability and selectivity of MOFs.

Three Novel Isomeric Zinc Metal–Organic Frameworks from a Tetracarboxylate Linker

Co-reporter:Yun-Xia Hu, Hai-Bo Ma, Bo Zheng, Wen-Wei Zhang, Shengchang Xiang, Lu Zhai, Li-Feng Wang, Banglin Chen, Xiao-Ming Ren, and Junfeng Bai

Inorganic Chemistry 2012 Volume 51(Issue 13) pp:7066-7074

Publication Date(Web):June 18, 2012

DOI:10.1021/ic202085j

Three porous supramolecular isomers (IZE-1, IZE-2, and IZE-3) with the same framework component [Zn2(EBTC)(H2O)2] (EBTC = 1,1′-ethynebenzene-3,3′,5,5′-tetracarboxylate) were successfully constructed by finely tuning the reaction condition. Although both IZE-1 and IZE-2 are constructed from the linear EBTC subunits and one kind of regular [Zn2(CO2)4] paddlewheels, their frameworks exhibit two different (3,4)-c net of fof (sqc1575) and sqc1572, respectively, resulting in cavities with different size and shape. However, as for isomer IZE-3, the EBTC ligands are bent and one-half of the [Zn2(CO2)4] paddlewheels are distorted, leading to a novel (3,4,4)-c hyx net with point symbol (6.72)4(62.82.102)(72.82.112) and vertex symbol (6.7.7)4(72.72.8.8.12.12)(6.6.8.8.102.102). Quantum chemical calculations by DFT indicate that the three isomers have very close thermodynamic stabilities, which may explain that subtle condition change leads to variation of the frameworks. Further theoretical semiempirical investigation on the interactions between solvent molecules and compounds shows different hydrogen binding patterns in good agreement with the experimental observations. Furthermore, they exhibit good solid-state luminescence properties with long lifetime.

A Series of Four-Connected Entangled Metal–Organic Frameworks Assembled from Pamoic Acid and Pyridine-Containing Ligands: Interpenetrating, Self-Penetrating, and Supramolecular Isomerism

Co-reporter:Suna Wang, Ruirui Yun, Yanqiang Peng, Qingfu Zhang, Jing Lu, Jianmin Dou, Junfeng Bai, Dacheng Li, and Daqi Wang

Crystal Growth & Design 2012 Volume 12(Issue 1) pp:79-92

Publication Date(Web):November 7, 2011

DOI:10.1021/cg2008057

Five novel compounds, {[Ni(PA)(bpe)(H2O)2]·DMF}n (1), {[Zn(PA)(bpe)]·DMF}n (2), {[Zn(PA)(bpe)]·2DMF·CH3OH}n (3), {[Cd2(PA)2(bpe)2(H2O)]·3.5H2O}n (4), {[Ni2(PA)2(bpp)2(H2O)3]·2DMF}n (5), based on pamoic acid (H2PA) (bpe = 1,2-bi(4-pyridyl)ethane, bpp = 1,3-bi(4-pyridyl)propane) have been synthesized. In such a system, both the PA2– anion ligand and dipyridyl ligands act as bipodal linkers, connecting the metal centers in square or tetrahedral geometries into 4-connected topologies with different entangled modes: 3-fold interpenetrating CdSO4 net (65.8) (1), roto-translational [2 + 2] interpenetrating diamond pseudosupramolecular isomers (2 and 3), 3-fold interpenetrating (6.74.8)(64.7.8) (4) and (6.85)(64.82) net with both 2-fold interpenetrating and self-penetrating characters (5), respectively. The formation of unique penetrating frameworks was investigated in detail. Gas adsorption and photoluminescent properties of the compounds have also been explored.

Water Stable Metal–Organic Framework Evolutionally Formed from a Flexible Multidentate Ligand with Acylamide Groups for Selective CO2 Adsorption

Co-reporter:Zhiyong Lu, Hang Xing, Ran Sun, Junfeng Bai, Baishu Zheng, and Yizhi Li

Crystal Growth & Design 2012 Volume 12(Issue 3) pp:1081-1084

Publication Date(Web):January 18, 2012

DOI:10.1021/cg201594p

A water stable porous metal–organic framework has been synthesized through an evolution approach in terms of both structures and properties. This interesting pillar-layered MOF ({[Cu2(TCMBT)(bpp)(μ3-OH)]·6H2O}n (1)) constructed from a flexible ligand possesses a BET surface area of 808.5 m2 g–1 and exhibits good selectivities of CO2/N2 (20.1:1) and CO2/CH4(4.0:1), which are comparable to those of the ZIF materials reported by Yaghi’s group. The excellent water stability of complex 1 would be quite preferable in practical application.

Synthesis, crystal structures, and photoluminescence of two novel zinc coordination polymers built from 2,2’-(ethyne-1,2-diyl)diterephthalate

Co-reporter:Yun-Xia Hu, Li-Feng Wang, Wen-Wei Zhang, Yi-Zhi Li, Xiao-Ming Ren, Junfeng Bai

Inorganic Chemistry Communications 2012 Volume 17() pp:173-176

Publication Date(Web):March 2012

DOI:10.1016/j.inoche.2011.12.048

Two coordination polymers, [Zn(EDDT)0.5(H2O)2] (1) and [Zn(EDDT)0.5(BPE)]⋅xG (2) (EDDT = 2,2’-(ethyne-1,2-diyl)diterephthalate, BPE = 1,2-bi(4-pyridyl)ethane, G = guest molecule), were solvothermally synthesized from the rigid planar linker of EDDT and the coligand of BPE, respectively, in which complex 1 displays 2D [Zn(EDDT)0.5] coordination layer, and the resulting 3D supramolecular network is formed via interlayer H-bonding interactions, whereas complex 2 exhibits an intriguing micropourous framework via the coordination of auxiliary ligand BPE. Interestingly, both of them show enhanced strong blue luminescence.Two novel coordination polymers, 2D layer motif of [Zn(EDDT)0.5 ∙ 2H2O] (1) and 3D microporous network of [Zn(EDDT)0.5∙(BPE)]⋅xG (2), built from the rigid planar ligand 2,2'-(ethyne-1,2-diyl)diterephthalate (EDDT) and the pillaring auxiliary ligand 1, 2-bi(4-pyridyl)ethane (BPE), exhibit enhanced strong solid-state luminescence.Highlights► Zinc coordination polymers built from rigid planar tetracarboxylate ligand of 2, 2'-(ethyne-1, 2-diyl)diterephthalate (EDDT). ► 2D layered or 3D micropourous supramolecular network. ► Strong blue emission in the solid state at room temperature.

Synthesis, structure, novel topology and reversible crystal-to-amorphous transformation of calcium coordination polymers from a flexible tripodal acid with additional amide groups

Co-reporter:Congyu Zuo, Junfeng Bai, Ran Sun, Yizhi Li

Inorganica Chimica Acta 2012 Volume 383() pp:305-311

Publication Date(Web):30 March 2012

DOI:10.1016/j.ica.2011.11.029

Two novel coordination polymers, [Ca(HTCMBT)(H2O)2]n (1) and {[Ca6(TCMBT)4(H2O)14]·(H2O)3}n (2), have been successfully synthesized from a tripodal flexible ligand, N,N′,N″-tris(carboxymethyl)-1,3,5-benzenetricarboxamide (H3TCMBT). Single crystal X-ray diffraction analyses reveal that 1 possesses a 2D network, in which each double layer is composed of dinuclear calcium clusters and OSBUs, and such layers further stack through hydrogen bonds to form a 3D supramolecular framework, while 2 exhibits a 3D architecture comprising mononuclear and dinuclear calcium units and OSBUs, which is a quite rare (5,6,8)-connected net with an unprecedented {3.46.52.6}2{32.44.54.64.7}{32.48.57.69.72} topology. In addition, 2 displays an interesting reversible crystal-to-amorphous transformation.Graphical abstractOne of two novel calcium(II) complexes from a flexible tripodal acid with amide groups exhibits a rare (5,6,8)-connected net with an unprecedented {3.46.52.6}2{32.44.54.64.7}{32.48.57.69.72} topology and an interesting reversible crystal-to-amorphous transformation.Highlights► Two calcium coordination polymers have been synthesized from a tripodal flexible ligand. ► Complex 1 and 2 possess 2D and 3D networks, respectively. ► They all have organic secondary building units with each constructed by two ligands. ► Complex 2 exhibits an unprecedented topology and reversible crystal-to-amorphous transformation.

Controlling the shifting degree of interpenetrated metal–organic frameworks by modulator and temperature and their hydrogen adsorption properties

Co-reporter:Jingui Duan, Junfeng Bai, Baishu Zheng, Yizhi Li and Wenchao Ren

Chemical Communications 2011 vol. 47(Issue 9) pp:2556-2558

Publication Date(Web):06 Jan 2011

DOI:10.1039/C0CC04146G

For the first time, the shifting degree of pcu-type interpenetrated framework was well controlled by employing a modulator and changing the temperature, in which their evacuated samples are almost non-crystalline products with different meso- and microstructures, resulting in different hydrogen adsorption properties.

A hierarchical supra-nanostructure of HKUST-1 featuring enhanced H2 adsorption enthalpy and higher mesoporosity

Co-reporter:Haiqiang Du, Junfeng Bai, Congyu Zuo, Zhifeng Xin and Jinbo Hu

CrystEngComm 2011 vol. 13(Issue 10) pp:3314-3316

Publication Date(Web):16 Mar 2011

DOI:10.1039/C1CE05124E

A hierarchical supra-nanostructure of HKUST-1 was synthesized by directly mixing solutions of copper acetate and H3BTC (H3BTC = 1,3,5-benzenetricarboxylic acid) under ambient conditions, which exhibits enhanced H2 adsorption enthalpy and higher mesoporosity.

Temperature-dependent supramolecular isomerism in three zinc coordination polymers with pamoic acid and 1,4-bis(imidazol-1-ylmethyl)-benzene

Co-reporter:Suna Wang, Yanqiang Peng, Xilian Wei, Qingfu Zhang, Daqi Wang, Jianmin Dou, Dacheng Li and Junfeng Bai

CrystEngComm 2011 vol. 13(Issue 17) pp:5313-5316

Publication Date(Web):18 Jul 2011

DOI:10.1039/C1CE05463E

Three supramolecular isomeric metal–organic frameworks (MOFs) have been synthesized at different temperatures, exhibiting a structural progression from 2D (4,4) layer structures (α and β) to a 3D acentric 3-fold diamondoid network (γ).

Enhanced CO2 Binding Affinity of a High-Uptake rht-Type Metal−Organic Framework Decorated with Acylamide Groups

Co-reporter:Baishu Zheng ; Junfeng Bai ; Jingui Duan ; Lukasz Wojtas ;Michael J. Zaworotko

Journal of the American Chemical Society 2010 Volume 133(Issue 4) pp:748-751

Publication Date(Web):December 21, 2010

DOI:10.1021/ja110042b

An rht-type metal−organic framework (MOF) prepared from M2(carboxylate)4 (M = Cu, Co) paddlewheel clusters and a flexible C3-symmetric hexacarboxylate ligand with acylamide groups exhibits larger CO2 uptake, an enhanced heat of adsorption, and higher selectivity toward CO2/N2 in comparison with what was previously observed for an analogous MOF with alkyne groups.

A new kind CO2/CH4 separation material: open ended nitrogen doped carbon nanotubes formed by direct pyrolysis of metal organic frameworks

Co-reporter:Yongming Shen and Junfeng Bai

Chemical Communications 2010 vol. 46(Issue 8) pp:1308-1310

Publication Date(Web):15 Jan 2010

DOI:10.1039/B913820J

Unprecedented open ended nitrogen doped carbon nanotubes prepared by direct pyrolysis of [Co(HTTG)(H2O)2]n (TTG= N,N′,N′′-1,3,5-triazine-2,4,6-triyltris-glycine) show among the largest surface area of multiwalled nanotubes and high CO2/CH4 adsorption selectivity which increases with increasing of nitrogen content.

Topology diversity and reversible crystal-to-amorphous transformation properties of 3D cobalt coordination polymers from a series of 1D rodlike dipyridyl-containing building blocks and a flexible tripodal acid with additional amide groups

Co-reporter:Tianyin Min, Bo Zheng, Junfeng Bai, Ran Sun, Yizhi Li and Zhuxiu Zhang

CrystEngComm 2010 vol. 12(Issue 1) pp:70-72

Publication Date(Web):25 Aug 2009

DOI:10.1039/B911380K

Three novel cobalt(II) coordination polymers based on 1D rodlike dipyridyl-containing chains and a flexible tripodal acid with additional amide groups with unprecedented (3, 5) and (4, 4, 5) connected topology with a Schläfli symbol of (5, 62) (53, 64, 7, 82), and (5, 65)2 (53, 66, 7)2 (64, 8, 10) were reported along with interesting reversible crystal-to-amorphous transformation properties.

Hierarchically Micro- and Mesoporous Coordination Polymer Nanostructures with High Adsorption Performance

Co-reporter:Zhifeng Xin, Junfeng Bai, Yongming Shen and Yi Pan

Crystal Growth & Design 2010 Volume 10(Issue 6) pp:2451

Publication Date(Web):April 20, 2010

DOI:10.1021/cg901520r

Hierarchically micro- and mesoporous supra-nanostructure, Cu-BDC and Cr-BDC (BDC = 1,4-benzenedicarboxylate), were prepared in which the mesopores are arranged in a disordered fashion. N2, H2, CO2, and CH4 adsorption properties of them have been investigated at low and higher pressures, indicating that they are new porous materials with relatively high performance. Most interestingly, Cr-BDC exhibits high H2 adsorption isosteric heat and higher uptakes of CO2 and H2 among these coordination polymer particle materials.

Metal-dependent dimensionality in coordination polymers of a semi-rigid dicarboxylate ligand with additional amide groups: Syntheses, structures and luminescent properties

Co-reporter:Jingui Duan, Baishu Zheng, Junfeng Bai, Qiang Zhang, Congyu Zuo

Inorganica Chimica Acta 2010 Volume 363(Issue 13) pp:3172-3177

Publication Date(Web):25 October 2010

DOI:10.1016/j.ica.2010.05.057

Three new coordination polymers, [CdL(H2O)3·H2O]n (1), [MnL(H2O)2]n (2) and [ZnL]n (3) (L = 2,2′-[1,4-bis(-benzamido)]diacetate) have been hydrothermally synthesized. Complex 1 and complex 2 are 1-D infinite zigzag chain and 2-D rectangular grid networks, respectively, in which are further stabilized by hydrogen bonds, thus affording two 3-D supramolecular frameworks. Complex 3 exhibits a (4, 4)-connected PtS topology. Moreover, an unusual phenomenon has been observed that the dimension of these coordination polymers gradually increases with the decrease of coordination numbers of metal ions. In addition, complex 1 exhibits a strong blue luminescence in the solid state at room temperature and may be potential candidate for luminescent materials.Three different dimensional transition metal polymers with a semi-rigid ligand have been hydrothermally synthesized and structural characterized, in which unusually, the dimension of these coordination polymers gradually increases with the decrease of coordination number of metal center.

Synthesis and Enhanced H2 Adsorption Properties of a Mesoporous Nanocrystal of MOF-5: Controlling Nano-/Mesostructures of MOFs To Improve Their H2 Heat of Adsorption

Co-reporter:Dr. Zhifeng Xin; Junfeng Bai; Yi Pan; Michael J. Zaworotko

Chemistry - A European Journal 2010 Volume 16( Issue 44) pp:13049-13052

Publication Date(Web):

DOI:10.1002/chem.201001700

An unprecedented nanoscale trilayered polythreading coordination array hierarchically formed from 2D square grid networks and induced by protonated 1,2-bis(4-pyridyl)ethane

Co-reporter:Bo Zheng and Junfeng Bai

CrystEngComm 2009 vol. 11(Issue 2) pp:271-273

Publication Date(Web):05 Nov 2008

DOI:10.1039/B815555K

An unprecedented nanoscale trilayered coordination assembly hierarchically formed from 2D square grid networks by the reaction of CdII hydroxide with mixed ligands squarate and 1,2-bis(4-pyridyl)ethane, which also exhibits a novel polythreading topology of 2D(+) + 2 × 2D(−) → 2D.

Novel symmetrical coralloid Cu 3D superstructures: Solid-state synthesis from a Cu-carboxylate MOF and their in-situ thermal conversion

Co-reporter:Lingyun Chen, Yongming Shen, Junfeng Bai, Chunzhao Wang

Journal of Solid State Chemistry 2009 Volume 182(Issue 8) pp:2298-2306

Publication Date(Web):August 2009

DOI:10.1016/j.jssc.2009.06.007

We describe here a one-step solid-state process for the synthesis of metal three-dimensional (3D) superstructures from a metal-organic framework (MOF). Novel symmetrical coralloid Cu 3D superstructures with surface interspersed with clusters of Cu nanoparticles were successfully synthesized by thermolysis of the [Cu3(btc)2] (btc=benzene-1,3,5-tricarboxylato) MOF in a one-end closed horizontal tube furnace (OCTF). The obtained products were characterized by TGA, FT-IR, XRD, EDX, SEM, TEM, HRTEM and SAED. Different reaction conditions were discussed. Furthermore, the synthesized Cu samples were converted into CuO microstructures by in-situ calcination in the air. In addition, the possible formation mechanism was also proposed. This method is a simple and facile route, which builds a direct linkage between metal-carboxylate MOF crystals and metal nano- or microstructures and also opens a new application field of MOFs.Novel symmetrical coralloid Cu 3D superstructures were synthesized by thermolysis of the [Cu3(btc)2] (btc=benzene-1,3,5-tricarboxylato) MOF microcrystals in a one-end closed horizontal tube furnace (OCTF).

Solid-state thermolysis of [MnO]12 containing molecular clusters into novel MnO nano- and microparticles

Co-reporter:Lingyun Chen, Hang Xing, Yongming Shen, Junfeng Bai, Guoqing Jiang

Journal of Solid State Chemistry 2009 Volume 182(Issue 6) pp:1387-1395

Publication Date(Web):June 2009

DOI:10.1016/j.jssc.2009.03.002

Novel MnO nano- and microparticles including spherical nanoparticles and various micropolyhedra of pyramid-like, truncated rectangular pyramid-like, cubic, and rhombic dodecahedral particles, were controllably synthesized via solid-state thermolysis of inorganic core containing molecular clusters [Mn12O12(O2CR)16(H2O)4] (R=C6H5, CH3, and C6H5OCH2) in a conventional horizontal tube furnace. Among them, pyramid-like, truncated rectangular pyramid-like, cubic, and rhombic dodecahedral MnO submicroscale particles were reported for the first time. The products were characterized by XRD, XPS, Raman spectrum, SEM, EDX, TEM and HRTEM. During the reaction process, thermolysis temperature, reaction time, and different molecular clusters {Mn12} precursors with different organic ligands as well play important roles in determining the sizes and shapes of the final products. The formed MnO nanospheres from [Mn12O12(O2CC6H5)16(H2O)4] at 400 °C for 10 h exhibited weak ferromagnetic behavior at low temperature which may be due to the size-effect of nanomaterials. Furthermore, the possible formation mechanism was also discussed.Novel MnO nano- and microparticles were controlled synthesized by solid-state thermolysis of inorganic core containing molecular clusters [Mn12O12(O2CR)16(H2O)4] (R=C6H5, CH3, and C6H5OCH2) in a conventional tubular furnace.

Large-scale synthesis of uniform spinel ferrite nanoparticles from hydrothermal decomposition of trinuclear heterometallic oxo-centered acetate clusters

Co-reporter:Lingyun Chen, Yongming Shen, Junfeng Bai

Materials Letters 2009 Volume 63(Issue 12) pp:1099-1101

Publication Date(Web):15 May 2009

DOI:10.1016/j.matlet.2009.02.034

A series of uniform spinel ferrite MFe2O4 (M = Ni, Co, Mn, and Zn) nanoparticles (NPs) were successfully synthesized on a large scale by direct hydrothermal decomposition of the trinuclear heterometallic oxo-centered acetate cluster of [MFe2O(CH3CO2)6(H2O)3]nH2O in solution. The crystal structure, composition and size of the synthesized NPs were characterized by X-ray diffraction (XRD), inductively coupled plasma atomic emission spectrometer (ICP-AES), transmission electron microscope (TEM) and high-resolution (HRTEM). Magnetic investigation revealed that all the synthesized MFe2O4 NPs showed superparamagnetic properties at room temperature. The possible formation mechanism was also proposed.

One-step solid-state thermolysis of a metal–organic framework: a simple and facile route to large-scale of multiwalled carbon nanotubes

Co-reporter:Linyun Chen, Junfeng Bai, Chunzhao Wang, Yi Pan, Manfred Scheer and Xiaozeng You

Chemical Communications 2008 (Issue 13) pp:1581-1583

Publication Date(Web):31 Jan 2008

DOI:10.1039/B718476J

We report a simple and facile solid-state approach to large-scale synthesis of multiwalled carbon nanotubes (MCNTs), for the first time, by one-step direct thermolysis of a metal–organic framework [Ni3(btc)2·12H2O] (btc = benzene-1,3,5-tricarboxylato) in a one-end closed conventional horizontal tube furnace under relatively low temperature without using any additional carrier gas or catalyst.

An unprecedented nanoporous and fluorescent supramolecular framework with an SrAl2 topology controllably synthesized from a flexible ditopic acid

Co-reporter:Su-Na Wang, Yong Yang, Junfeng Bai, Yi-Zhi Li, Manfred Scheer, Yi Pan and Xiao-Zeng You

Chemical Communications 2007 (Issue 42) pp:4416-4418

Publication Date(Web):17 Aug 2007

DOI:10.1039/B710389A

A novel supramolecular framework was obtained from the ligand H2BDOA (benzene-1,3-dioxyacetic acid) that exhibited an SrAl2 topology with 1.7 × 1.7 nm channels formed by strong hydrogen bonds and demonstrated an interesting crystal-to-crystal transformation property.

Unprecedented interweaving of single-helical and unequal double-helical chains into chiral metal–organic open frameworks with multiwalled tubular structures

Co-reporter:Su-Na Wang, Hang Xing, Yi-Zhi Li, Junfeng Bai, Manfred Scheer, Yi Pan and Xiao-Zeng You

Chemical Communications 2007 (Issue 22) pp:2293-2295

Publication Date(Web):07 Mar 2007

DOI:10.1039/B701186E

Two novel chiral metal–organic open frameworks with unprecedented multiwalled tubular channels and interweaving of single-helical and unequal double-helical units were reported, which possess novel four-connected 428310 topology and represent the first examples of functional metal–organic frameworks based on both flexible tripodal and flexible bisdentate ligands.

2D and 3D Cadmium(II) Coordination Polymers from a Flexible Tripodal Ligand of 1,3,5-Tris(carboxymethoxy)benzene and Bidentate Pyridyl-Containing Ligands with Three-, Eight- and Ten-Connected Topologies

Co-reporter:Suna Wang;Hang Xing;Yizhi Li;Junfeng Bai;Yi Pan;Manfred Scheer;Xiaozeng You

European Journal of Inorganic Chemistry 2006 Volume 2006(Issue 15) pp:

Publication Date(Web):1 JUN 2006

DOI:10.1002/ejic.200600189

Four novel cadmium(II) coordination polymers, [Cd₃(TCMB)₂(4,4′-bipy)(H₂O)₁₆]_n (1), [Cd₃(TCMB)₂(bpe)(H₂O)₁₃]_n (2), [Cd₃(TCMB)₂(bpe)₂(H₂O)₄]_n (3), and [Cd₃(TCMB)₂(dpp)₂(H₂O)₃]_n (4), [TCMB = 1,3,5-tris(carboxymethoxy)benzene, 4,4-bipy = (4,4-bipyridine), bpe = 1,2-bis(4-pyridyl)ethane, dpp = 1,3-bis(4-pyridyl)propane] have been hydrothermally synthesized by the self-assembly of the flexible tripodal acid TCMB and Cd(OAc)₂·2H₂O with pyridyl-containing ligands possessing different flexibilities. Single-crystal X-ray diffraction analysis reveals that the four polymers exhibit novel frameworks due to diverse coordination modes and different conformations of the flexible TCMB as well as pyridyl-containing ligands. Complex 1 shows a unique twofold parallel interpenetrating 2D honeycomb network structure with an unusual 6³ topology, in which two different large hexagonal rings are arranged alternately, with extraordinarydimensions of ca. 22.172(6) × 12.947(2) Å (A) and 17.233(2) × 12.947(2) Å (B) based on the distances of the atoms at the opposite positions of the rings. Complex 2 is almost isostructural to complex 1, except that the bidentate bpe ligands bridge the cadmium centers in an anti conformation, rendering the network more flexible. Complex 3 features a 3D network with one of the scarce eight-connected (4⁶, 6¹⁴, 8⁸)(4³)₂ topologies based on the rare CdI₂-type layer constructed from secondary building units (SBUs) of rare [Cd₃(CO₂)₄]^2– isosceles triangle cadmium clusters. Complex 4 possesses distorted CdI₂-type layers constructed from unprecedented ten-connected Cd₃ clusters which are linked by more flexible dpp ligands in a trans-gauche (TG) conformation in (4,4) networks, leading to another 3D framework of the unusual (4¹⁸, 6²⁴, 8³)(4³)₂ topology. Such an arrangement represents the highest connected topology presently known for the frameworks. Among them, complex 1 displays photoluminescent properties at 460 nm due to the ligand-to-metal charge transfer (LMCT). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Luminescent Open-Framework Antiferromagnet – Hydrothermal Syntheses, Structures, and Luminescent and Magnetic Properties of Two Novel Coordination Polymers: [Zn(pdoa)(bipy)]n and {[Mn(pdoa)(bipy)](bipy)}n [pdoa = 2,2′-(1,3-phenylenedioxy)bis(acetate); bipy = 4,4′-bipyridine]

Co-reporter:Xian-Lan Hong;Junfeng Bai;You Song;Yi-Zhi Li;Yi Pan

European Journal of Inorganic Chemistry 2006 Volume 2006(Issue 18) pp:

Publication Date(Web):31 JUL 2006

DOI:10.1002/ejic.200600198

Two coordination polymers of mixed ligands, 2,2′-(1,3-phenylenedioxy)bis(acetate) (pdoa) and 4,4′-bipyridine (bipy),namely [Zn(pdoa)(bipy)]_n (1) and {[Mn(pdoa)(bipy)](bipy)}_n (2), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction and IR spectra. Complex 1 crystallizes in the triclinic space group P with a = 6.8826(18) Å, b = 11.202(3) Å, c = 12.295(3) Å, α = 86.854(4)°, β = 85.759(5)°, γ = 72.629(4)° and is a novel folded-paper-shaped coordination compound with polymeric sheets formed by the five-coordinate Zn^II centers and bridging pdoa and bipy. Complex 2 crystallizes in the monoclinic space group P2₁/c with a = 11.507(2) Å, b = 23.254(5) Å, c = 9.8710(19) Å, β = 96.418(4)° and exhibits a robust three-dimensional framework with nanosized rectangular channels (11.627 × 11.507 Å). They both display blue fluorescent emission and could be considered as new luminescent materials. In addition, the magnetic properties of complex 2 were investigated and the magnetic susceptibility data were rationally fitted with g = 2.072(5), J = –1.11(4) cm^–1, and zJ′ =–0.161(7) cm^–1, showing it is an unprecedented luminescent open-framework antiferromagnet.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Synthesis, structures and properties of alkaline earth metal benzene-1,4-dioxylacetates with three-dimensional hybrid networks

Co-reporter:Yong Yang, Guoqing Jiang, Yi-Zhi Li, Junfeng Bai, Yi Pan, Xiao-Zeng You

Inorganica Chimica Acta 2006 Volume 359(Issue 10) pp:3257-3263

Publication Date(Web):1 July 2006

DOI:10.1016/j.ica.2006.03.038

Three novel alkaline earth metal benzene-1,4-dioxylacetates M(L)H2O (M = Ca, Sr or Ba, L = benzene-1,4-dioxylacetate) with three-dimensional (3D) hybrid frameworks were reported. Both Ca(L)H2O (1) and Sr(L)H2O (2) crystallize in the monoclinic space group P21/c while Ba(L)H2O (3) in the monoclinic space group P21. As determined by X-ray single-crystal analysis, in these compounds each metal ion is coordinated by eight O atoms: four from different carboxylate groups, two from one carboxylate group, one from the ether oxygen and one from one water molecule. Each L2− ligand coordinates to five alkaline earth metal centers through one of its ether oxygen atoms and two carboxylate groups adopting novel μ3-η2:η2-bridging and μ2-η1:η1-bridging coordination modes to give rise to a 3D network. The luminescence analysis shows that complexes 1 and 2 exhibit fluorescence in the solid state at room temperature.Three novel alkaline earth metal benzene-1,4-dioxylacetates M(L)H2O (M = Ca, Sr or Ba, L = benzene-1,4-dioxylacetate) with three-dimensional frameworks were synthesized and characterized. The luminescence analysis found that 1 and 2 showed fluorescence in the solid state at room temperature.

Finely tuning MOFs towards high-performance post-combustion CO2 capture materials

Co-reporter:Qian Wang, Junfeng Bai, Zhiyong Lu, Yi Pan and Xiaozeng You

Chemical Communications 2016 - vol. 52(Issue 3) pp:NaN452-452

Publication Date(Web):2015/10/15

DOI:10.1039/C5CC07751F

CO2 capture science and technology, particularly for the post-combustion CO2 capture, has become one of very important research fields, due to great concern of global warming. Metal–organic frameworks (MOFs) with a unique feature of structural fine-tunability, unlike the traditional porous solid materials, can provide many and powerful platforms to explore high-performance adsorbents for post-combustion CO2 capture. Until now, several strategies for finely tuning MOF structures have been developed, in which either the larger quadrupole moment and polarizability of CO2 are considered: metal ion change (I), functional groups attachment (II) and functional group insertion (III), vary the electronic nature of the pore surface; or targeting the smaller kinetic diameter of CO2 over N2 is focused on: framework interpenetration (IV), ligand shortening (V) and coordination site shifting (VI) contract the pore size of frameworks to improve their CO2 capture properties. In this review, from the viewpoint of synthetic materials scientists/chemists, we would like to introduce and summarize these strategies based upon recent work published by other groups and ourselves.

Finely tuning MOFs towards high performance in C2H2 storage: synthesis and properties of a new MOF-505 analogue with an inserted amide functional group

Co-reporter:Mingxing Zhang, Bin Li, Yunzhi Li, Qian Wang, Wenwei Zhang, Banglin Chen, Shuhua Li, Yi Pan, Xiaozeng You and Junfeng Bai

Chemical Communications 2016 - vol. 52(Issue 45) pp:NaN7244-7244

Publication Date(Web):2016/05/04

DOI:10.1039/C6CC03198F

Aiming to improve the acetylene (C2H2) storage capability of MOFs, we successfully designed NJU-Bai 17, a new analogue of MOF-505 with an inserted amide functional group which exhibits almost record high C2H2 uptakes of 222.4 cm3 g−1 at 296 K and 296 cm3 g−1 at 273 K under 1 bar. This result has been further supported by the determination of the heat of C2H2 adsorption and Grand Canonical Monte Carlo (GCMC) and first-principle calculations.

Highly selective CO2 capture of an agw-type metal–organic framework with inserted amides: experimental and theoretical studies

Co-reporter:Jingui Duan, Zhen Yang, Junfeng Bai, Baishu Zheng, Yizhi Li and Shuhua Li

Chemical Communications 2012 - vol. 48(Issue 25) pp:NaN3060-3060

Publication Date(Web):2011/12/12

DOI:10.1039/C2CC16231H

An amide-inserted metal–organic framework (NJU-Bai3) presents high storage and high selectivity toward CO2 and combines these two interesting characters which strongly support our expectation that amide groups can significantly enhance the CO2 binding ability and selectivity of MOFs.

High and selective CO2 capture by two mesoporous acylamide-functionalized rht-type metal–organic frameworks

Co-reporter:Baishu Zheng, Zhen Yang, Junfeng Bai, Yizhi Li and Shuhua Li

Chemical Communications 2012 - vol. 48(Issue 56) pp:NaN7027-7027

Publication Date(Web):2012/01/20

DOI:10.1039/C2CC17593B

Two mesoporous and flexible acylamide-functionalized rht-type MOFs exhibit not only high excess unsaturation CO2 uptake (157 wt%) at 20 bar and 273 K, but also good selectivity of CO2/CH4 (8.6) and CO2/N2 (34.3). The advantages of acylamide groups for CO2 capture have been further confirmed by GCMC and first-principles calculations.

Controlling the shifting degree of interpenetrated metal–organic frameworks by modulator and temperature and their hydrogen adsorption properties

Co-reporter:Jingui Duan, Junfeng Bai, Baishu Zheng, Yizhi Li and Wenchao Ren

Chemical Communications 2011 - vol. 47(Issue 9) pp:NaN2558-2558

Publication Date(Web):2011/01/06

DOI:10.1039/C0CC04146G

For the first time, the shifting degree of pcu-type interpenetrated framework was well controlled by employing a modulator and changing the temperature, in which their evacuated samples are almost non-crystalline products with different meso- and microstructures, resulting in different hydrogen adsorption properties.

One-step solid-state thermolysis of a metal–organic framework: a simple and facile route to large-scale of multiwalled carbon nanotubes

Co-reporter:Linyun Chen, Junfeng Bai, Chunzhao Wang, Yi Pan, Manfred Scheer and Xiaozeng You

Chemical Communications 2008(Issue 13) pp:NaN1583-1583

Publication Date(Web):2008/01/31

DOI:10.1039/B718476J

We report a simple and facile solid-state approach to large-scale synthesis of multiwalled carbon nanotubes (MCNTs), for the first time, by one-step direct thermolysis of a metal–organic framework [Ni3(btc)2·12H2O] (btc = benzene-1,3,5-tricarboxylato) in a one-end closed conventional horizontal tube furnace under relatively low temperature without using any additional carrier gas or catalyst.

Unprecedented interweaving of single-helical and unequal double-helical chains into chiral metal–organic open frameworks with multiwalled tubular structures

Co-reporter:Su-Na Wang, Hang Xing, Yi-Zhi Li, Junfeng Bai, Manfred Scheer, Yi Pan and Xiao-Zeng You

Chemical Communications 2007(Issue 22) pp:NaN2295-2295

Publication Date(Web):2007/03/07

DOI:10.1039/B701186E

Two novel chiral metal–organic open frameworks with unprecedented multiwalled tubular channels and interweaving of single-helical and unequal double-helical units were reported, which possess novel four-connected 428310 topology and represent the first examples of functional metal–organic frameworks based on both flexible tripodal and flexible bisdentate ligands.

An unprecedented nanoporous and fluorescent supramolecular framework with an SrAl2 topology controllably synthesized from a flexible ditopic acid

Co-reporter:Su-Na Wang, Yong Yang, Junfeng Bai, Yi-Zhi Li, Manfred Scheer, Yi Pan and Xiao-Zeng You

Chemical Communications 2007(Issue 42) pp:NaN4418-4418

Publication Date(Web):2007/08/17

DOI:10.1039/B710389A

A novel supramolecular framework was obtained from the ligand H2BDOA (benzene-1,3-dioxyacetic acid) that exhibited an SrAl2 topology with 1.7 × 1.7 nm channels formed by strong hydrogen bonds and demonstrated an interesting crystal-to-crystal transformation property.

A new kind CO2/CH4 separation material: open ended nitrogen doped carbon nanotubes formed by direct pyrolysis of metal organic frameworks

Co-reporter:Yongming Shen and Junfeng Bai

Chemical Communications 2010 - vol. 46(Issue 8) pp:NaN1310-1310

Publication Date(Web):2010/01/15

DOI:10.1039/B913820J

Unprecedented open ended nitrogen doped carbon nanotubes prepared by direct pyrolysis of [Co(HTTG)(H2O)2]n (TTG= N,N′,N′′-1,3,5-triazine-2,4,6-triyltris-glycine) show among the largest surface area of multiwalled nanotubes and high CO2/CH4 adsorption selectivity which increases with increasing of nitrogen content.

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Abstract

Abstract