Co-reporter:Jiang Sun, Yanxia Yu, Chunhua Liu, and Shengbin Lei
The Journal of Physical Chemistry C 2017 Volume 121(Issue 6) pp:
Publication Date(Web):January 17, 2017
DOI:10.1021/acs.jpcc.6b12180
Surface-assisted reaction has gained much attention in the field of nanoscience and nanotechnology, due largely to its irreplaceability in the fabrication of one- and two-dimensional polymers on various substrates. In this work, surface- and guest-molecule-promoted product selection from a dynamic covalent library as well as transimination were investigated at the liquid/solid interface by virtue of scanning tunneling microscopy (STM). The significant role played by the substrate in the selection and redistribution of the products is highlighted, which arises from the self-assembling and competitive adsorption of the products. Furthermore, our result demonstrated that the surface-assisted redistribution of the products can be further promoted by addition of a proper guest, which, by forming supramolecular assemblies, enhances the selection toward specific products.
Co-reporter:Lirong Xu, Yanxia Yu, Jianbin Lin, Xin Zhou, Wei Quan Tian, Damian Nieckarz, Pawel Szabelski and Shengbin Lei
Nanoscale 2016 vol. 8(Issue 16) pp:8568-8574
Publication Date(Web):21 Mar 2016
DOI:10.1039/C5NR07663C
Two-dimensional polymers are of great interest for many potential applications in nanotechnology. The preparation of crystalline 2D polymers with a tunable band gap is critical for their applications in nano-electronics and optoelectronics. In this work, we try to tune the band gap of 2D imine polymers by expanding the conjugation of the backbone of aromatic diamines both laterally and longitudinally. STM characterization reveals that the regularity of the 2D polymers can be affected by the existence of lateral bulky groups. Density functional theory (DFT) simulations discovered a significant narrowing of the band gap of imine 2D polymers upon the expansion of the conjugation of the monomer backbone, which has been confirmed experimentally by UV absorption measurements. Monte Carlo simulations help us to gain further insight into the controlling factors of the formation of regular 2D polymers, which demonstrated that based on the all rigid assumption, the coexistence of different conformations of the imine moiety has a significant effect on the regularity of the imine 2D polymers.
Co-reporter:Jiang Sun, Xin Zhou and Shengbin Lei
Chemical Communications 2016 vol. 52(Issue 56) pp:8691-8694
Publication Date(Web):08 Jun 2016
DOI:10.1039/C5CC09276K
A two-dimensional covalent organic framework (2D COF), synthesized on a highly oriented pyrolytic graphite (HOPG) surface with benzene-1,3,5-tricarbaldehyde and p-phenylenediamine as the precursors, is used as a host to accommodate three guest molecules, coronene, copper phthalocyanine (CuPc), and fluorine-substituted copper phthalocyanine (F16CuPc). The host–guest interaction and dynamic behavior were investigated by scanning tunneling microscopy and density functional theory.
Co-reporter:Yanxia Yu, Ling Yang, Chunhua Liu, Wei Quan Tian, Yan Wang and Shengbin Lei
Chemical Communications 2016 vol. 52(Issue 53) pp:8317-8320
Publication Date(Web):02 Jun 2016
DOI:10.1039/C6CC02975B
Hierarchical networks, constructed by non-covalent bond stabilized cross-junctions of covalent one-dimensional molecular wires, are synergistically formed at the liquid/solid interface through in situ on-surface condensation of aromatic amines and aldehydes. Our investigation demonstrates the significant impact of the concentration and structure of monomers on the hierarchical construction of these nanoarchitectures at the interface.
Co-reporter:Chunhua Liu;Dr. Wei Zhang;Dr. Qingdao Zeng;Dr. Shengbin Lei
Chemistry - A European Journal 2016 Volume 22( Issue 20) pp:6768-6773
Publication Date(Web):
DOI:10.1002/chem.201601199
Abstract
By introducing an azobenzene group to the backbone of diboronic acid, we have obtained a surface-confined, photoresponsive single-layer covalent organic framework with long-range order and almost entire surface coverage. Scanning tunneling microscopic characterization indicates that though the covalent linkage provides a significant locking effect, isomerization can still happen under UV irradiation, which causes destruction of the surface COF. Furthermore, the decomposed surface COF can recover upon annealing. This photoinduced decomposition provides a facile approach for the controlled capture and release of targeted objects using these nanoporous surface COFs as a host, which has been demonstrated in this work using copper phthalocyanine as a model guest.
Co-reporter:Zeqi Zha, Lirong Xu, Zhikui Wang, Xiaoguang Li, Qinmin Pan, Pingan Hu, and Shengbin Lei
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 32) pp:17837
Publication Date(Web):July 23, 2015
DOI:10.1021/acsami.5b04185
To harness the electroactivity of anthraquinone as an electrode material, a great recent effort have been invested to composite anthraquinone with carbon materials to improve the conductivity. Here we report on a noncovalent way to modify three-dimensional graphene with anthraquinone moieties through on-surface synthesis of two-dimensional covalent organic frameworks. We incorporate 2,6-diamino-anthraquinone moieties into COF through Schiff-base reaction with benzene-1,3,5-tricarbaldehyde. The synthesized COF -graphene composite exhibits large specific capacitance of 31.7 mF/cm2. Long-term galvanostatic charge/discharge cycling experiments revealed a decrease of capacitance, which was attributed to the loss of COF materials and electrostatic repulsion accumulated during charge–discharge circles which result in the poor electrical conductivity between 2D COF layers.Keywords: alkaline electrolyte; anthraquinone; capacitor; covalent organic framework; graphene; noncovalent functionalization
Co-reporter:Xin Zhou, Longtao Jiang, Shengbin Lei, Wei Quan Tian, and Gaohui Wu
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 23) pp:12688
Publication Date(Web):May 26, 2015
DOI:10.1021/acsami.5b02906
The authors discovered the self-lubrication behavior of TiB2/Al composite and pointed out that the materials responsible for the self-lubrication behavior comes from the oxidation of TiB2. Atomic/friction force microscopy and first-principles calculations have been employed to study the self-lubrication microscopic mechanism of TiB2/Al composite. Atomic force microscopy confirms the existence of a soft film with nanometer thickness on the TiB2 surface, which was attributed to H3BO3 film. Friction measurements revealed much smaller friction force on this H3BO3 nanofilm than that on Al matrix. The detailed structure and interactions among H3BO3 molecules and between the H3BO3 sheet and substrate were explored by density functional theory based calculations. The details of adsorption of H3BO3 sheet on TiB2 and TiO2 surface were scrutinized and the potential of the relative movement between H3BO3 sheets were scanned and compared with that of graphite. The generation of H3BO3 film, the strong chemical adsorption of H3BO3 film on the surface of the composite, the strong hydrogen bonding in H3BO3 film, and small potential in the relative slide between H3BO3 sheets warrant the good self-lubricant properties of TiB2/Al metal matrix composites.Keywords: first-principles calculations; friction measurements; H3BO3 sheets; hydrogen bond; self-lubrication microscopic mechanism; TiB2/Al composite;
Co-reporter:Lirong Xu, Lili Cao, Zongxia Guo, Zeqi Zha and Shengbin Lei
Chemical Communications 2015 vol. 51(Issue 41) pp:8664-8667
Publication Date(Web):13 Apr 2015
DOI:10.1039/C5CC02232K
An imine-based 2D polymer side-functionalized with o-hydroxyl group was designed in regard to its potential ability to serve as a chelating agent and synthesized on a highly oriented pyrolytic graphite surface with a relatively low annealing temperature. When annealed to a higher temperature the o-hydroxyl group reacts further with the imine group, leading to the formation of oxazoline, which causes significant distortion to the network. The formation of oxazoline was further confirmed by ATR-FTIR.
Co-reporter:Yanxia Yu
The Journal of Physical Chemistry C 2015 Volume 119(Issue 29) pp:16777-16784
Publication Date(Web):July 1, 2015
DOI:10.1021/acs.jpcc.5b04938
The surface-mediated synthesis of ordered linear or zigzag polymers on a highly oriented pyrolytic graphite surface was investigated either at a solid/liquid interface or with moderate heating under low vacuum. Scanning tunneling microscopy (STM) reveals the submolecular details of the structure and growth dynamics of surface-confined one-dimensional polymers. We discovered that the substituent and concentration of monomers have a significant effect on the assembling structure of the in-situ-synthesized one-dimensional polymer at the octanoic acid/graphite interface.
Co-reporter:Lili Cao, Lirong Xu, Dahui Zhao, Kazukuni Tahara, Yoshito Tobe, Steven De Feyter and Shengbin Lei
Chemical Communications 2014 vol. 50(Issue 80) pp:11946-11949
Publication Date(Web):14 Aug 2014
DOI:10.1039/C4CC03658A
A highly efficient recognition phenomenon was observed between alkoxylated arylene–ethynylene macrocycles bearing identical side chains but different core size, which is based on van der Waals interactions between alkoxy chains. The ratio of both molecules and the environment of each molecule have been statistically analyzed to quantify the recognition efficiency.
Co-reporter:Lirong Xu;Xin Zhou; Wei Quan Tian;Teng Gao;Yan Feng Zhang; Shengbin Lei; Zhong Fan Liu
Angewandte Chemie International Edition 2014 Volume 53( Issue 36) pp:9564-9568
Publication Date(Web):
DOI:10.1002/anie.201400273
Abstract
The integration of 2D covalent organic frameworks (COFs) with atomic thickness with graphene will lead to intriguing two-dimensional materials. A surface-confined covalently bonded Schiff base network was prepared on single-layer graphene grown on copper foil and the dynamic reaction process was investigated with scanning tunneling microscopy. DFT simulations provide an understanding of the electronic structures and the interactions between the surface COF and graphene. Strong coupling between the surface COF and graphene was confirmed by the dispersive bands of the surface COF after interaction with graphene, and also by the experimental observation of tunneling condition dependent contrast of the surface COF.
Co-reporter:Lirong Xu;Xin Zhou; Wei Quan Tian;Teng Gao;Yan Feng Zhang; Shengbin Lei; Zhong Fan Liu
Angewandte Chemie 2014 Volume 126( Issue 36) pp:9718-9722
Publication Date(Web):
DOI:10.1002/ange.201400273
Abstract
The integration of 2D covalent organic frameworks (COFs) with atomic thickness with graphene will lead to intriguing two-dimensional materials. A surface-confined covalently bonded Schiff base network was prepared on single-layer graphene grown on copper foil and the dynamic reaction process was investigated with scanning tunneling microscopy. DFT simulations provide an understanding of the electronic structures and the interactions between the surface COF and graphene. Strong coupling between the surface COF and graphene was confirmed by the dispersive bands of the surface COF after interaction with graphene, and also by the experimental observation of tunneling condition dependent contrast of the surface COF.
Co-reporter:Xiuling Sun, Jia Zhang, Xiaona Wang, Cuiyun Zhang, Pingan Hu, Youbing Mu, Xiaobo Wan, Zongxia Guo and Shengbin Lei
Chemical Communications 2013 vol. 49(Issue 87) pp:10317-10319
Publication Date(Web):11 Sep 2013
DOI:10.1039/C3CC45431B
On graphene grown on copper foil, oligothiophenes form identical supramolecular assemblies on different copper facets. Most importantly, we found that the graphene ripple structures, even with a height as small as ∼0.5 nm, can significantly alter the molecule–substrate interaction, which has never been observed previously.
Co-reporter:Lirong Xu, Liu Yang, Lili Cao, Tian Li, Shusen Chen, Dahui Zhao, Shengbin Lei and Jun Ma
Physical Chemistry Chemical Physics 2013 vol. 15(Issue 28) pp:11748-11757
Publication Date(Web):14 May 2013
DOI:10.1039/C3CP51413G
In this work we provide a systematic scanning tunneling microscopy (STM) study on the self-assembling and mixing behavior of Arylene Ethynylene Macrocycles (AEMs) containing 1,4-phenylene, 1,4-naphthylene or 9,10-anthrylene substituents at the solid/liquid interface. The effect of bulky substituents on the self-assembly structure was investigated and we found that 1,4-phenylene ethynylene macrocycle (AEM-B) and 1,4-naphthylene ethynylene macrocycle (AEM-N) form four and three different patterns at the 1,2,4-trichloride benzene (TCB)/graphite interface, respectively, and a significant concentration effect was observed for both molecules. 9,10-anthrylene ethynylene macrocycle (AEM-A) only forms a filled honeycomb structure at relatively high concentrations. The effect of bulky substituents was attributed to the steric hindrance, which hinders full interdigitation of alkoxy chains. The mixing behavior of binary mixtures of arylene ethynylene macrocycles was also investigated at the TCB/HOPG interface. The results demonstrate that the steric hindrance brought by the bulky groups does not enable sufficient recognition between identical molecules at the interface and random mixing was observed for binary mixtures of AEM-B and AEM-N. The mixing behavior of AEMs could also be predicted by the parameter called the 2D isomorphism coefficient.
Co-reporter:Lirong Xu, Xin Zhou, Yanxia Yu, Wei Quan Tian, Jun Ma, and Shengbin Lei
ACS Nano 2013 Volume 7(Issue 9) pp:8066
Publication Date(Web):August 8, 2013
DOI:10.1021/nn403328h
We performed a co-condensation reaction between aromatic aldehyde and aromatic diamine monomers on a highly oriented pyrolytic graphite surface either at a solid/liquid interface at room temperature or in low vacuum with moderate heating. With this simple and moderate methodology, we have obtained surface-confined 2D covalent organic frameworks (COFs) with few defects and almost entire surface coverage. The single crystalline domain can extend to more than 1 μm2. By varying the backbone length of aromatic diamines the pore size of 2D surface COFs is tunable from ∼1.7 to 3.5 nm. In addition, the nature of the surface COF can be modified by introducing functional groups into the aromatic amine precursor, which has been demonstrated by introducing methyl groups to the backbone of the diamine. Formation of small portions of bilayers was observed by both scanning tunneling microscopy (STM) and AFM, which clearly reveals an eclipsed stacking manner.Keywords: co-condensation; covalent organic framework; Schiff base; STM; surface-confined reaction
Co-reporter:Lirong Xu, Liu Yang and Shengbin Lei
Nanoscale 2012 vol. 4(Issue 15) pp:4399-4415
Publication Date(Web):03 May 2012
DOI:10.1039/C2NR30122A
In this review, we give a brief account on the recent scanning tunneling microscopy investigation of interfacial structures and properties of π-conjugated semiconducting oligomers and polymers, either at the solid–air (including solid–vacuum) or at the solid–liquid interface. The structural aspects of the self-assembly of both oligomers and polymers are highlighted. Conjugated oligomers can form well ordered supramolecular assemblies either at the air–solid or liquid–solid interface, thanks to the relatively high mobility and structural uniformity in comparison with polymers. The backbone structure, substitution of side chains and functional groups can affect the assembling behavior significantly, which offers the opportunity to tune the supramolecular structure of these conjugated oligomers at the interface. For conjugated polymers, the large molecular weight limits the mobility on the surface and the distribution in size also prevents the formation of long range ordered supramolecular assembly. The submolecular resolution obtained on the assembling monolayers enables a detailed investigation of the chain folding at the interface, both the structural details and the effect on electronic properties. Besides the ability in studying the assembling structures at the interfaces, STM also provides a reasonable way to evaluate the distribution of the molecular weight of conjugated polymers by statistic of the contour length of the adsorbed polymer chains. Both conjugated oligomers and polymers can form composite assemblies with other materials. The ordered assembly of oligomers can act as a template to controllably disperse other molecules such as coronene or fullerene. These investigations open a new avenue to fine tune the assembling structure at the interface and in turn the properties of the composite materials. To summarize scanning tunneling microscopy has demonstrated its surprising ability in the investigation of the assembling structures and properties of conjugated oligomers and polymers. The information obtained could benefit the understanding of the elements affecting the film morphology and helps the optimization of device performance.
Co-reporter:Jinne Adisoejoso, Kazukuni Tahara, Shengbin Lei, Paweł Szabelski, Wojciech Rżysko, Koji Inukai, Matthew O. Blunt, Yoshito Tobe, and Steven De Feyter
ACS Nano 2012 Volume 6(Issue 1) pp:897
Publication Date(Web):December 29, 2011
DOI:10.1021/nn204398m
With the use of a single building block, two nanoporous patterns with nearly equal packing density can be formed upon self-assembly at a liquid–solid interface. Moreover, the formation of both of these porous networks can be selectively and homogenously induced by changing external parameters like solvent, concentration, and temperature. Finally, their porous properties are exploited to host up to three different guest molecules in a spatially resolved way.Keywords: Monte Carlo simulations; multicomponent; phase behavior; scanning tunneling microscopy; self-assembly
Co-reporter:Shengbin Lei, Ke Deng, Zhun Ma, Wei Huang and Chen Wang
Chemical Communications 2011 vol. 47(Issue 31) pp:8829-8831
Publication Date(Web):20 Jun 2011
DOI:10.1039/C1CC12468D
Copper phthalocyanine can assemble along PPE backbones into molecular arrays and 2D assemblies with structural parameters different from its intrinsic 2D crystal. The template effect depends on the match between the size of phthalocyanine and the repeating period of the PPE backbone.
Co-reporter:Shengbin Lei, Kazukuni Tahara, Klaus Müllen, Paweł Szabelski, Yoshito Tobe, and Steven De Feyter
ACS Nano 2011 Volume 5(Issue 5) pp:4145
Publication Date(Web):April 18, 2011
DOI:10.1021/nn200874k
We present a systematic scanning tunneling microscopic study on the mixing behavior of molecules (DBAs) with different alkyl substituents at the solid–liquid interface to reveal the phase behavior of complex systems. The phase behavior of binary mixtures of alkylated DBAs at the solid–liquid interface can be predicted by the 2D isomorphism coefficient. In addition, we also investigated the influence of coadsorption of template molecules on the phase behavior of DBA mixtures. Coadsorption of these molecules significantly promotes mixing of DBAs, possibly by affecting the recognition between alkyl chains. Monte Carlo simulations prove that the 2D isomorphism coefficient can predict the phase behavior at the interface. These results are helpful for the understanding of phase behavior of complex assembling systems and also for the design of programmable porous networks and hierarchical architectures at the solid–liquid interface.Keywords: multicomponent; phase behavior; physisorption; scanning tunneling microscopy; self-assembly
Co-reporter:Shengbin Lei, Yanlian Yang, Qingdao Zeng, and Chen Wang
Langmuir 2011 Volume 27(Issue 7) pp:3496-3501
Publication Date(Web):February 22, 2011
DOI:10.1021/la104219z
The morphology of the composite film of organic semiconductors determines the properties and performances of devices to a large extent. In this work, we present a combined AFM and STM study on the interfacial structures of CuPcOC8 and CuPcOC8/PmPV composite films on graphite surface. For CuPcOC8 thin films, the face-on epitaxial growth of CuPcOC8 could persist within 3 to 5 monolayers and the formation of π−π stacked columns will occur with edge-on configuration when the film thickness further increases. For the CuPcOC8/PmPV composite film with 1:1 weight ratio, STM results reveal a preferential adsorption of PmPV on graphite surface, while AFM results indicate the phase segregation in the upper layer. STM also reveals in the molecular scale good compatibility of CuPcOC8 with PmPV.
Co-reporter:Dr. Yong-Tao Shen ;Ningbo Zhu;Xue-Mei Zhang;Dr. Ke Deng; Wei Feng;Qifan Yan; Shengbin Lei; Dahui Zhao; Qing-Dao Zeng; Chen Wang
Chemistry - A European Journal 2011 Volume 17( Issue 25) pp:7061-7068
Publication Date(Web):
DOI:10.1002/chem.201003589
Abstract
The unfolding process and self-assembly of a foldable oligomer (foldamer 1) at the liquid/graphite interface were investigated by scanning tunnelling microscopy. At the level of molecular conformation, we identified several molecular conformations (Az, B, C, D, E) that represent intermediate states during unfolding, which may help to elucidate the unfolding process at the liquid/graphite interface. Adsorption at the interface traps the intermediate states of the unfolding process, and STM has proved to be a powerful technique for investigating folding and unfolding of a foldamer at the molecular level, which are not accessible by other methods. The STM observations also revealed that varying the solvent and/or concentration results in different self-assemblies of foldamer 1 as a result of variations in molecular conformations. The solvent and concentration effects were attributed to the changes in existing states (extended or folded) of foldamers in solution, which in turn affect the distribution of adsorbed molecular conformations at the interface. This mechanism is quite different from other systems in which solvent and concentration effects were also observed.
Co-reporter:Zhun Ma, Yi-Bao Li, Ke Deng, Sheng-Bin Lei, Yan-Yan Wang, Pei Wang, Yan-Lian Yang, Chen Wang and Wei Huang
The Journal of Physical Chemistry C 2010 Volume 114(Issue 26) pp:11460-11465
Publication Date(Web):June 10, 2010
DOI:10.1021/jp1002353
An oligo(phenyleneethynylene), with hydroxyl as end-groups of cross-shaped four alkoxy side chains (OH-OPE), was designed and synthesized to investigate the effects of the symmetry of molecular structure as well as the hydrogen bonding and interaction between alkoxy side chains on its supramolecular assemblies by scanning tunneling microscopy (STM). OH-OPEs fabricate by themselves two distinct patterns on highly orientated pyrolytic graphite (HOPG) surface with dissimilar surface coverages, symmetries, and stabilities. The surface coverage of both patterns shows a clear dependence on the concentration of OH-OPE. Contrary to the general concept, in the present case, the D1 pattern with higher packing density is favored at low concentration, which is possibly due to the existence of specific interactions (H-bonds) between the molecules and the difference in the number of H-bonds in these patterns. Coadsorption of diacids of shorter alkyl chains could help to stabilize the low density, porous pattern, whereas diacids with too long alkyl chains destabilize it. Due to the flexibility of the side chains, the coadsorption of shorter diacids does not significantly change the packing of OH-OPE. Our results point to the conclusion that the coadsorption is due to host−guest accommodation rather than hydrogen bond complexation.
Co-reporter:Yanxia Yu, Ling Yang, Chunhua Liu, Wei Quan Tian, Yan Wang and Shengbin Lei
Chemical Communications 2016 - vol. 52(Issue 53) pp:NaN8320-8320
Publication Date(Web):2016/06/02
DOI:10.1039/C6CC02975B
Hierarchical networks, constructed by non-covalent bond stabilized cross-junctions of covalent one-dimensional molecular wires, are synergistically formed at the liquid/solid interface through in situ on-surface condensation of aromatic amines and aldehydes. Our investigation demonstrates the significant impact of the concentration and structure of monomers on the hierarchical construction of these nanoarchitectures at the interface.
Co-reporter:Lili Cao, Lirong Xu, Dahui Zhao, Kazukuni Tahara, Yoshito Tobe, Steven De Feyter and Shengbin Lei
Chemical Communications 2014 - vol. 50(Issue 80) pp:NaN11949-11949
Publication Date(Web):2014/08/14
DOI:10.1039/C4CC03658A
A highly efficient recognition phenomenon was observed between alkoxylated arylene–ethynylene macrocycles bearing identical side chains but different core size, which is based on van der Waals interactions between alkoxy chains. The ratio of both molecules and the environment of each molecule have been statistically analyzed to quantify the recognition efficiency.
Co-reporter:Xiuling Sun, Jia Zhang, Xiaona Wang, Cuiyun Zhang, Pingan Hu, Youbing Mu, Xiaobo Wan, Zongxia Guo and Shengbin Lei
Chemical Communications 2013 - vol. 49(Issue 87) pp:NaN10319-10319
Publication Date(Web):2013/09/11
DOI:10.1039/C3CC45431B
On graphene grown on copper foil, oligothiophenes form identical supramolecular assemblies on different copper facets. Most importantly, we found that the graphene ripple structures, even with a height as small as ∼0.5 nm, can significantly alter the molecule–substrate interaction, which has never been observed previously.
Co-reporter:Jiang Sun, Xin Zhou and Shengbin Lei
Chemical Communications 2016 - vol. 52(Issue 56) pp:NaN8694-8694
Publication Date(Web):2016/06/08
DOI:10.1039/C5CC09276K
A two-dimensional covalent organic framework (2D COF), synthesized on a highly oriented pyrolytic graphite (HOPG) surface with benzene-1,3,5-tricarbaldehyde and p-phenylenediamine as the precursors, is used as a host to accommodate three guest molecules, coronene, copper phthalocyanine (CuPc), and fluorine-substituted copper phthalocyanine (F16CuPc). The host–guest interaction and dynamic behavior were investigated by scanning tunneling microscopy and density functional theory.
Co-reporter:Lirong Xu, Lili Cao, Zongxia Guo, Zeqi Zha and Shengbin Lei
Chemical Communications 2015 - vol. 51(Issue 41) pp:NaN8667-8667
Publication Date(Web):2015/04/13
DOI:10.1039/C5CC02232K
An imine-based 2D polymer side-functionalized with o-hydroxyl group was designed in regard to its potential ability to serve as a chelating agent and synthesized on a highly oriented pyrolytic graphite surface with a relatively low annealing temperature. When annealed to a higher temperature the o-hydroxyl group reacts further with the imine group, leading to the formation of oxazoline, which causes significant distortion to the network. The formation of oxazoline was further confirmed by ATR-FTIR.
Co-reporter:Shengbin Lei, Ke Deng, Zhun Ma, Wei Huang and Chen Wang
Chemical Communications 2011 - vol. 47(Issue 31) pp:NaN8831-8831
Publication Date(Web):2011/06/20
DOI:10.1039/C1CC12468D
Copper phthalocyanine can assemble along PPE backbones into molecular arrays and 2D assemblies with structural parameters different from its intrinsic 2D crystal. The template effect depends on the match between the size of phthalocyanine and the repeating period of the PPE backbone.
Co-reporter:Lirong Xu, Liu Yang, Lili Cao, Tian Li, Shusen Chen, Dahui Zhao, Shengbin Lei and Jun Ma
Physical Chemistry Chemical Physics 2013 - vol. 15(Issue 28) pp:NaN11757-11757
Publication Date(Web):2013/05/14
DOI:10.1039/C3CP51413G
In this work we provide a systematic scanning tunneling microscopy (STM) study on the self-assembling and mixing behavior of Arylene Ethynylene Macrocycles (AEMs) containing 1,4-phenylene, 1,4-naphthylene or 9,10-anthrylene substituents at the solid/liquid interface. The effect of bulky substituents on the self-assembly structure was investigated and we found that 1,4-phenylene ethynylene macrocycle (AEM-B) and 1,4-naphthylene ethynylene macrocycle (AEM-N) form four and three different patterns at the 1,2,4-trichloride benzene (TCB)/graphite interface, respectively, and a significant concentration effect was observed for both molecules. 9,10-anthrylene ethynylene macrocycle (AEM-A) only forms a filled honeycomb structure at relatively high concentrations. The effect of bulky substituents was attributed to the steric hindrance, which hinders full interdigitation of alkoxy chains. The mixing behavior of binary mixtures of arylene ethynylene macrocycles was also investigated at the TCB/HOPG interface. The results demonstrate that the steric hindrance brought by the bulky groups does not enable sufficient recognition between identical molecules at the interface and random mixing was observed for binary mixtures of AEM-B and AEM-N. The mixing behavior of AEMs could also be predicted by the parameter called the 2D isomorphism coefficient.
![[2,2':5',2'':5'',2'''-QUATERTHIOPHENE]-5-CARBOXALDEHYDE, 3,3'''-DIOCTYL-](http://img.cochemist.com/ccimg/635300/635299-27-3.png)
![[2,2':5',2'':5'',2'''-QUATERTHIOPHENE]-5-CARBOXALDEHYDE, 3,3'''-DIOCTYL-](http://img.cochemist.com/ccimg/635300/635299-27-3_b.png)
