Two D–A type asymmetrical Zn(II) coordination complexes, [ZnL1(C2H5OH)] (1) (H2L1 = 2,4-di-tert-butyl-6-((E)-((2-((E)-(2-hydroxybenzylidene)amino)-4-nitrophenyl)imino)methyl)phenol) and [ZnL2(DMF)]·DMF (2) (H2L2 = 1-((E)-((2-((E)-(3,5-di-tert-butyl-2-hydroxybenzylidene)amino)-5-nitrophenyl)imino)methyl)naphthalen-2-ol), were designed, synthesized, and studied. Their fluorescence properties were comprehensively analysed based on their single-crystal structures. The results showed that the red-shift of fluorescence emission from complex 1 to complex 2 was successfully pushed via the strategy of extending the π–π stacking interaction.

•A novel copper coordination polymer based on γ-aminobutyric acid ligand is synthesized and structurally characterized.•Complex 1 exhibits a 1D chain structure including μ3-OH-Cu3 cluster as a building block.•The magnetism studies show that complex 1 exhibit antiferromagnetic interactions.•Two different magnetic topologies have been applied to analysis the magnetic exchange coupling.A copper coordination polymer with γ-aminobutyric acid (GABA), {[Cu3(GABA)2(NO3)2(OH)2(H2O)2] (NO3)2·2H2O}n (1), has been synthesized and characterized by single-crystal X-ray diffraction, IR, PXRD, TGA and elemental analysis. It exhibits a 1D chain structure including μ3-OH-Cu3 cluster as a building block. The strong H-bonding links these chains to form 2D sheet structure and the main intermolecular interaction between the 2D sheets is electrostatic interaction. According to the crystal structure of complex 1, the magnetic properties of complex 1 have been investigated by the cluster and cycle magnetic coupling models. There are three different magnetic coupling pathways of Cu(II) (J1, J2, J3) from each method and the resulting fitted curves based on the magnetic parameters of both methods compare well with the experiment values.A novel copper coordination polymer based on γ-aminobutyric acid ligand which exhibits a 1D chain structure including the tri-nuclear copper cluster as building block has been synthesized. The magnetic couplings between the different Cu pairs in this 1D coordination polymer have been calculated through cluster and cycle models.Download high-res image (109KB)Download full-size image

Two types of Cu(II)–UMP-L coordination polymers, {[Cu2(UMP)2(bpda)2(H2O)3]·10H2O}n (1) and {[Cu2(UMP)2(bpe)2(H2O)2]·7H2O}n (2) (UMP = uridine 5′-monophosphate, bpda = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, bpe = 1,2-bis(4-pyridyl)ethylene), were designed and synthesized for researching the effect of auxiliary ligand. X-ray single-crystal diffraction analysis revealed that complex 1 is the first example of a 1D parallel double-bridged coordination polymer in a nucleotide–metal coordination complex, while complex 2 is a 2D grid coordination polymer. Based on their crystal structure analysis, their chirality, including molecular chirality, supramolecular helical chirality and auxiliary ligand's extended axial chirality (EAC), was studied by aqueous solution and solid state circular dichroism (CD) spectroscopy. The length and conjugated auxiliary ligand had an influence on the EAC.

Three complexes, [Zn(H2L1)(CH3COO)]2·CH3OH (1), [Zn4(H2L2)2(CH3COO)4]·4DMF (2) and {[Zn4(L3)2(CH3COO)4]·DMSO}n (3) (H3L1 = 4-hydroxybenzoic acid (2-hydroxy-5-nitro-benzylidene)-hydrazide, H4L2 = 4-hydroxy-3-methoxybenzoic acid (2,3-dihydroxy-benzylidene)-hydrazide, H2L3 = (4-nitro-phenoxy)acetic acid (2-hydroxy-3-methoxy-benzylidene)-hydrazide)), have been synthesized and studied, in which three kinds of ligands have been designed by introducing diversified bridging-functional groups. The single-crystal X-ray diffraction analysis showed that 1–3 are dinuclear, linear tetranuclear and 1D chain coordination complexes, respectively, which were achieved by controlled synthesis of multinuclear complexes through ligand design. The luminescence properties of these crystallized complexes have been investigated both in solution and the solid state.

Four types of perylene diimide–amino acid derivatives (H2PDIAla, H2PDIGlu, H2PDIPhe, H2PDITyr) were chosen to interact with anions. The UV-vis, fluorescence (in DMF solution) and NMR spectra in DMSO-d6 solution were studied. The results indicated that the four types of derivatives exhibit specific selectivity and high sensitivity for F− and OH− ions. The NMR titrations of the derivatives with F− and OH− ions confirmed the synergetic effect of hydrogen bonding and anion–π interaction between the derivatives and the anions (F−, OH−). In addition, we made a simple test-paper to develop its potential applications.

•Asymmetric Schiff bases derived from diaminomaleonitrile (DAMN).•Metal coordination complexes with DAMN-based asymmetric Schiff bases.•Applications of complexes with DAMN-based asymmetric Schiff bases.Asymmetric Schiff bases, due to its asymmetric structure, can be used as asymmetric catalyst, antibacterial, and mimic molecules during simulate biological processes, etc. In recent years, research on synthesis and properties of asymmetric Schiff bases have become an increase interest of chemists. This review summarizes asymmetric Schiff bases derived from diaminomaleonitrile (DAMN) and DAMN-based asymmetric Schiff bases metal complexes. Applications of DAMN-based asymmetric Schiff bases are also discussed in this review.

•Three novel amino acid complexes with helical frameworks were obtained.•l-asparagine induces a chiral metal center and M-helixes into complex 1.•l-asparagine acts as both a tridentate and a bidentate ligand in complex 1.•The liquid and solid state CD spectra of both ligands and complexes were analyzed.Three novel complexes with helical two dimensional (2D) frameworks, [Ni(Asn)2(H2O)] (1) (HAsn = l-asparagine), [Cd(Gln)2]n (2) (HGln = l-glutamine) and [Zn(Gln)2]n (3), have been studied based on X-ray single crystal diffraction analysis. l-asparagine induces two kinds of chirality, the chiral Ni(II) center and the supramolecular M-helixes, into complex 1. l-glutamine induces one kind of chirality, the helixes, into complexes 2 and 3, respectively. Combining the crystal structures of complexes 1–3, the final aggregate chirality induced by coordinated bond interactions can be detected by the liquid state circular dichroism (CD) spectra while the solid state CD spectra of complexes 1–3 additionally reflect the final aggregate chirality induced by weak interactions.The chirality transfer in three novel amino acid complexes was discussed in crystallography. The solution and solid state circular dichroism (CD) spectra of both ligands and complexes were measured to research the sign-to-configuration relationship.

•The first single crystal structure of neutral coordination complex of adenosine-5'-diphosphaten (ADP-Cu) was reported.•Molecular and supramolecular chirality of ADP-Cu were investigated intensively for the first time.•The research results in this work are unique and fundamental for coordination and supramolecular chemistry of diphosphate nucleotide.The first neutral coordination complex of adenosine-5′-diphosphate (ADP) with transition metal Cu(II) ion, [Cu(phen)(H2ADP)(NO3)]·H2O (ADP–Cu) (ADP = adenosine-5′-diphosphate, phen = 1, 10-phenanthroline monohydrate) has been synthesized and investigated by X-ray single-crystal diffraction method. Based on its crystal structure and supramolecular assembly analysis, the molecular and supramolecular chirality of ADP–Cu was studied comprehensively by liquid- and solid-state circular dichroism (CD) spectroscopy. It is the first example of the study about the chirality and supramolecular chirality for polyphosphate nucleotide coordination complex.The chirality and supramolecular chirality for polyphosphate nucleotide coordination complex was studied based on single crystal structure analysis combined with liquid and solid state circular dichroism (CD) spectroscopy for the first time.

Halogen substituted β-amino acids, D,L-3-amino-3-(4-fluoro)phenylpropionic acid(D,L-HL1, 1) and D,L-3-amino-3-(4-bromo)phenylpropionic acid(D,L-HL2, 2), as well as their Cu(II) coordination complexes [Cu(L1)2(CH3OH)2]·2CH3OH(3) and [Cu(L2)2(CH3OH)2]·2CH3OH(4) were investigated and their single crystal structures were discussed in details. Supramolecular helical chains were found in β-amino acids 1 and 2 while there was no helix in their coordination complexes 3 and 4. The formation of supramolecular helixes could be due to the hydrogen bonds between terminal ―NH3+ and adjacent ―COO– in β-amino acids 1 and 2. While, this kind of hydrogen bonds could not be observed in their Cu(II) coordination complexes 3 and 4, in which central-symmetrical dimers could be formed via coplanar coordinated bonds(N―Cu―O) between ―NH2 and ―COO–.

Although complexation of hydrophilic guests inside the cavities of hydrophobic hosts is considered to be unlikely, we demonstrate herein the complexation between γ- and β-cyclodextrins (γ- and β-CDs) with an archetypal polyoxometalate (POM)—namely, the [PMo12O40]3– trianion—which has led to the formation of two organic–inorganic hybrid 2:1 complexes, namely [La(H2O)9]{[PMo12O40]⊂[γ-CD]2} (CD-POM-1) and [La(H2O)9] {[PMo12O40]⊂[β-CD]2} (CD-POM-2), in the solid state. The extent to which these complexes assemble in solution has been investigated by (i) 1H, 13C, and 31P NMR spectroscopies and (ii) small- and wide-angle X-ray scattering, as well as (iii) mass spectrometry. Single-crystal X-ray diffraction reveals that both complexes have a sandwich-like structure, wherein one [PMo12O40]3– trianion is encapsulated by the primary faces of two CD tori through intermolecular [C–H···O═Mo] interactions. X-ray crystal superstructures of CD-POM-1 and CD-POM-2 show also that both of these 2:1 complexes are lined up longitudinally in a one-dimensional columnar fashion by means of [O–H···O] interactions. A beneficial nanoconfinement-induced stabilizing effect is supported by the observation of slow color changes for these supermolecules in aqueous solution phase. Electrochemical studies show that the redox properties of [PMo12O40]3– trianions encapsulated by CDs in the complexes are largely preserved in solution. The supramolecular complementarity between the CDs and the [PMo12O40]3– trianion provides yet another opportunity for the functionalization of POMs under mild conditions by using host−guest chemistry.

•Structural diversity, pH sensitivity, and chirality of nucleotide ligands.•Nucleotide–metal complexes analyzed based on X-ray single crystal structures.•Rules of supramolecular self-assembly of nucleotide–metal coordination complexes.•Chirality and chirality delivery in nucleotide complex systems.•Functional nanomaterials with nucleotide complex as building blocks are summarized, including fluorescence, adaptive inclusion properties, molecular recognition, chiral resolution and so on.Nucleotides are essential components of DNA and RNA, and their functions depend mainly on the participation of metal ions. Thus, research into nucleotide–metal coordination complexes, including the affinities of different coordination donors for metal ions, molecular and crystal structures, supramolecular assembly, and functional nanoparticles, will contribute to the interdisciplinary field of chemistry, biology, and materials. Numerous achievements have been reported in this area but few comprehensive reviews have considered nucleotide–metal complexes from the viewpoints of crystallography and supramolecular chemistry, or aspects of their chirality and chirality delivery. In this review, we describe the coordination ability of nucleotide ligands, the structures and properties of nucleotide–metal coordination complexes, and supramolecular assemblies. We review mononuclear complexes, multinuclear complexes, 1D and 2D coordination polymers, and 3D supramolecular assemblies in terms of their structures, mainly based on their X-ray single crystal diffraction data. In particular, we highlight the chirality of nucleotide–metal complex, including their molecular chirality, supramolecular helical chirality, and extended axial chirality. Furthermore, we summarize the functional properties of nucleotide–metal nanomaterials, such as their luminescence, magnetism, and adaptive inclusion properties. We discuss the future challenges and opportunities of research into nucleotide–metal complex.

Different CMP–bpe–M(II) (CMP = cytidine monophosphate, bpe = bis(4-pyridyl)ethylene, M(II) = Mn2+ and Co2+) complexes are synthesized controllably based on pH control and well studied by X-ray single-crystal diffraction analysis. Interestingly, the suitable pH conditions are explored by considering the pre-organization modes of CMP, bpe, and M2+ in aqueous solution by fluorescence spectroscopy based on acid/basic titration. The organic base bpe serves as a small-molecule fluorescent probe to indicate the changes of pre-organization modes along with the changes of the solution acidity. Furthermore, a perfect self-complementary sugar–base hydrogen bond is first reported based on the crystal structure analysis in this work, and different chiralities and SHG activities of CMP–bpe–Mn(II) complexes obtained at different pH values are studied.

Two MOF-74 analogs with OH groups on 1D channel surfaces have been synthesized through multi-component self-assembly at room temperature. Their guest-free forms demonstrate a potential luminescent probe or sensor for small molecules, and OH-MOF-74 (2a) also showed exceptional fluorescence quenching and enhancement behavior for different types of aromatic molecules.

Reactions of deprotonated (E)-3-(quinolin-4-yl) acrylic acid (QCA) with nitrates of cadmium, in the presence or absence of auxiliary 4,4′-bipyridine (4,4′-bipy) ligand in CH3OH–DMF–H2O, produce three novel compounds with the formula of [Cd(QCA)2(H2O)]n (1), [Cd(QCA)2(4,4′-bipy)]n (2) and{[Cd(QCA)2(4,4′-bipy)1.5]·2.5H2O}n (3). Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra, thermogravimetric (TGA) and powder X-ray diffraction (PXRD) analysis. Compounds 1 and 2 displays 2D undulated and planar layered structures respectively, which are further connected by intermolecular hydrogen bonds to form a 3D supramolecular architecture. In compound 3, QCA and 4,4′-bipy ligands link Cd centers to generate 1D ladder-like chain. An unusual uudd cyclic water tetramer in the crystal lattice of 3 is observed as the second example reported until now. Obviously, the structural differences among them are attributable to the different molar ratio of QCA to auxiliary 4,4′-bipy ligand. Moreover, the photoluminescent properties of all the compounds have been investigated.

The synthesis, crystal structures, fluorescent properties and chirality of Zn(II) coordination complexes with two kinds of salen-type Schiff based ligands are reported. One of them is a chiral molecule and exhibits an unusually intense orange–red visible fluorescent emission in the present of THF, while the other is silent in photoluminescent emission.

Two kinds of tetranuclear Zn(II) molecular clusters with the designed aroylhydrazone Schiff base ligand (H3333L), [Zn4(HL)4]·3(DMF)·3(H2O) (1) and [Zn4(HL)2(CH3COO)4]·2(DMF)·2(CH3OH) (2), have been synthesized and studied. Molecular cluster 1 displayed a Zn4O4 boat-shaped core and 2 presented a discrete linear tetranuclear Zn(II) structure. The luminescent properties of the two molecular clusters have been investigated, which exhibit a wide range of photo-luminescence in different organic solvents.

•The chirality delivery in the crystallized coordination complex has been studied.•The path of chirality delivery in this complex is multiple and helical H-bonding.•Liquid- and solid-state CD spectroscopy confirm the mechanism of chirality delivery.The path of the chirality delivery in the crystalline and chiral nucleotide–Co(II) complex, [Co(GMP)(H2O)5]·3H2O (GMP = guanosine-5′-monophosphate), has been studied based on X-ray single crystal diffraction analysis, liquid- and solid-state circular dichroism (CD) spectroscopy. The multiple and helical H-bonding is a distinctive way of chirality delivery from the discrete molecules to three-dimensional supramolecular architecture.The molecular chirality of crystallized nucleotide-transition metal coordination complex is delivered to three-dimensional supramolecular architecture through multiple and helical H-bonding in its crystal lattice. Liquid- and solid-state CD spectroscopy confirm the novel path of chirality delivery.Figure optionsDownload full-size imageDownload as PowerPoint slide

A C–C coupling reaction has been achieved at room temperature by in situ ligand transformation. The iron(III) complexes before and after the in situ transformation, [FeNaL12(H2O)4]2·2H2O (1) (H2L1 = (Z)-2-(2-hydroxyl)benzylideneamino) and [FeL2]2·7.5H2O (2) (H3L2 = (E)-2-(2-hydroxyl-benzylideneamino)-3-hydroxyl-3-(2-hydroxyphenyl), have been studied by elemental analyses, FT-IR, UV–vis, TGA and X-ray single crystal diffraction analysis. The proposed mechanism of this in situ transformation has been determined based on structural evidence and theoretical calculations using the density functional theory (DFT) M06 method.

Chirality of a nucleotide–Cu(II) complex molecule, [CuNa(GMP)(HGMP)(H2O)7]·6(H2O)·CH3OH (GMP = guanosine 5′-monophosphate), is delivered to the three-dimensional supramolecular architecture by hydrogen bonding. Liquid- and solid-state circular dichroism (CD) spectroscopy are used to analyse the molecular and supramolecular chirality.

Four new complexes of fluoro-phenyl-acrylic acids (E)-3-(3-fluoro-phenyl)-acrylic acid (L1) [Mn3(L1)6(L2)2]·H2O·CH3CN (1), [Zn2(L1)4(L3)]n (2), [Mn(L1)2(H2O)2]n (3) and [Co(L1)2(H2O)2]n (4) (L2=1,10-phenanthroline, L3=4,4′-bipy) have been synthesized based on the molecular design and research of halogen–halogen interactions (especially fluoro–fluoro contact). The structure analyses reveal that complex 1 is a trinuclear complex, which is blocked by L2. Complex 2 is a 1D chain bridged through L3. Complexes 3 and 4 exhibit 2D grid like metal–organic framework structures through carboxylato bridge ligand. Variable-temperature magnetic measurements showed an antiferromagnetic interaction between Mn(II) ions and between Co(II) ions in complexes 3 and 4, respectively. A short C−F…F−C contact with a distance of 2.953 Å was found between the trinuclear coordination compound 1.Graphical AbstractThe short distance between F…F (2.953 Å) was found in the complex of [Mn3(L1)6(L2)2]·H2O·CH3CN (L1=(E)-3-(3–fluoro-phenyl)-acrylic acid, L2=1,–10–phenanthroline).Research highlights► Four new complexes of fluoro-phenyl-acrylic acids (E)-3-(3-fluoro-phenyl)-acrylic acid (L1) [Mn3(L1)6(L2)2]·H2O·CH3CN (1), [Zn2(L1)4(L3)]n (2), [Mn(L1)2(H2O)2]n (3) and [Co(L1)2(H2O)2]n (4) (L2=1,10-phenanthroline, L3=4,4′-bipy) have been synthesized based on the molecular design and research of halogen–halogen interactions (especially fluoro–fluoro contact). ► A short C−F…F−C contact with a distance of 2.953 Å was found between the trinuclear coordination compound 1. ► Variable-temperature magnetic measurements showed an antiferromagnetic interaction between Mn(II) ions and between Co(II) ions in complexes 3 and 4, respectively.

The asymmetrical tridentate Schiff base (H2L = (E)-N′-(2-hydroxybenzylidene)-4-hydroxybenzohydrazide) has been designed and synthesized. The four transition metal complexes with this ligand [Cu(HL)(NO3)](H2O) (1), [Zn2(HL)2(bipy)(H2O)2](NO3)2 (2), [Cu(HL)(H2O)]2(NO3)2 (3) and [Cu(HL)(Me2NCO)]2 (4) have been studied. The unsaturated coordination site of metal ion in complexes 1 and 2 is occupied by secondary ligand of nitrate and 4,4′-bipyridine. The crystal structure of complex 1 exhibits supramolecular framework with homochirality. Complexes 3 and 4 are dinuclear complexes bridged by the phenol oxygen atoms and the fifth coordination is occupied by H2O molecular and DMF anion respectively. Hydrogen bonding and π–π stacking exist in all four complexes to construct supramolecular architecture.

One-dimensional alternative chains of two lanthanum complexes: [La(L1)3(CH3OH)(H2O)2]·5H2O (L1=anion of α-cyano-4-hydroxycinnamic acid ) 1 and [La(L2)3(H2O)2]·3H2O (L2=anion of trans-3-(4-methyl-benzoyl)-acrylic acid) 2 were synthesized and structurally characterized by single-crystal X-ray diffraction, element analysis, IR and thermogravimetric analysis. The crystal structure data are as follows for 1: C31H36LaN3O17, triclinic, P  -1, a=9.8279(4)Å, b=11.8278(5)Å, c=17.8730(7)Å, α=72.7960(10)°α=72.7960(10)°, β=83.3820(10)°β=83.3820(10)°, γ=67.1650(10)ºγ=67.1650(10)º, Z=2Z=2, R1=0.0377R1=0.0377, wR2=0.0746wR2=0.0746; for 2: C33H37LaO14, triclinic, P  -1, a=8.7174(5)Å, b=9.9377(5)Å, c=21.153(2)Å, α=81.145(2)°α=81.145(2)°, β=87.591(2)°β=87.591(2)°, γ=67.345(5)°γ=67.345(5)°, Z=2Z=2, R1=0.0869R1=0.0869, wR2=0.220wR2=0.220. 1 is a rare example of the alternative chain constructed by syn–syn and anti–syn coordination mode of carboxylato ligand arranged along the chain alternatively. La(III) ions in 2 are linked by two η3–O bridges and four bridges (two η2–O and two η3–O) alternatively. Both of the linear coordination polymers grow into two- and three-dimensional networks by packing through extending hydrogen-bond network directed by ligands.3D H-bonding network directed by the ligand based on the rare alternative chain of lanthanum complex containing syn–syn and anti–syn coordination mode of α-cyano-4-hydroxycinnamic acid.

Two lanthanide complexes with acrylic acid ligand: [Ho(L)3(CH3OH)2]2·CH3OH·H2O (1) and [NH(Et)3]2[Lu(L)4]2·6CH3OH (2) (L=(E)-3-(2-hydroxyl-phenyl)-acrylic acid) are studied. The crystal structure data for 1: C59H60Ho2O24, orthorhombic, Pbcn, a=15.4289(12) Å, b=7.9585(6) Å, c=23.041(2) Å, β=99.657(2)°, Z=4, R1=0.0637, wR2=0.0919; for 2: C27H30.50LaO13.75, triclinic, P−1, a=13.3034(4) Å, b=13.3087(4) Å, c=14.5461(6) Å, α=85.932(2)°, β=64.611(2)°, γ=81.595(2)°, Z=2, R1=0.0394, wR2=0.0446. Two structure data were collected using graphite monochromated molybdenum Kα radiation and refined using full-matrix least square techniques on F2. Complex 2 is the first dimeric lanthanide complex anion. Two structures show dinuclear complexes with bis-monodentate and bidentate chelate bridge modes of carboxylato ligand. Bidentate chelate coordination mode were also included in these two complexes. The smallest bridge angle of bidentate chelate carboxylato bridge (η3-O, 104.70(9)°) has been found for the first time. Complexes 1 and 2 act as supramolecular synthons assembled by 2D and 3D hydrogen bonding in the crystal lattices.

The synthesis, crystal structures and molecular packing of the three trichromium metal string complexes [Cr3(dpa)4Cl(OC2H5)]OH·C2H5OC2H5·2.5H2O (1), [Cr3(dpa)4(OH)2]ClO4·3H2O (2) and [Cr3(dpa)4F2Na(H2O)BF4]BF4·CH3OH (3) (dpa−=bis(2-pyridyl)amido) have been studied. The crystal structure data for 1: C46H54ClCr3N12O5.5, monoclinic, P21/c, a=19.9998(4) Å, b=15.9756(3) Å, c=16.9943(3) Å, β=114.0548(8)°, Z=4, R1=0.0791, wR2=0.1927; for 2: C40H40ClCr3N12O9, orthogonal, Pna21, a=18.3373(2) Å, b=16.8220(2) Å, c=14.0268(2) Å, Z=4, R1=0.0683, wR2=0.1804; for 3: C41H38B2Cr3F10N12NaO2, monoclinic, P21/n, a=12.3902(1) Å, b=16.2081(2) Å, c=23.4119(3) Å, β=98.8725(6)°, Z=4, R1=0.0670, wR2=0.1568. The structure data were collected using graphite monochromated molybdenum Kα radiation and refined using full-matrix least square techniques on F2. The magnetic property of complex 1 was carried out on polycrystalline samples with a SQUID magnetometer. The IR, FAB-MS mass spectra of all complexes were also measured. In the three complexes, trichromium metal string complexes can be considered as mini-1D asymmetrically chains since the distance between the two axial ligands is around 1 nm. The types of hydrogen bonding in three complexes are C–H⋯O, C–H⋯Cl, C–H⋯F and O–H⋯O). 1 and 2 have a one-dimensional double-chain structures. 1 is a rare example of three-dimensional novel sandwich structure. In 3, one of the axial ligand, F− acts as a bridge ligand to link the sodium ion to the Cr3 axis with a bond angle of Cr(1)–F(1)–Na in 169.90(13)°. It can be considered as a metal string complex with an extra long axis.

Two MOF-74 analogs with OH groups on 1D channel surfaces have been synthesized through multi-component self-assembly at room temperature. Their guest-free forms demonstrate a potential luminescent probe or sensor for small molecules, and OH-MOF-74 (2a) also showed exceptional fluorescence quenching and enhancement behavior for different types of aromatic molecules.

A C–C coupling reaction has been achieved at room temperature by in situ ligand transformation. The iron(III) complexes before and after the in situ transformation, [FeNaL12(H2O)4]2·2H2O (1) (H2L1 = (Z)-2-(2-hydroxyl)benzylideneamino) and [FeL2]2·7.5H2O (2) (H3L2 = (E)-2-(2-hydroxyl-benzylideneamino)-3-hydroxyl-3-(2-hydroxyphenyl), have been studied by elemental analyses, FT-IR, UV–vis, TGA and X-ray single crystal diffraction analysis. The proposed mechanism of this in situ transformation has been determined based on structural evidence and theoretical calculations using the density functional theory (DFT) M06 method.

Different CMP–bpe–M(II) (CMP = cytidine monophosphate, bpe = bis(4-pyridyl)ethylene, M(II) = Mn2+ and Co2+) complexes are synthesized controllably based on pH control and well studied by X-ray single-crystal diffraction analysis. Interestingly, the suitable pH conditions are explored by considering the pre-organization modes of CMP, bpe, and M2+ in aqueous solution by fluorescence spectroscopy based on acid/basic titration. The organic base bpe serves as a small-molecule fluorescent probe to indicate the changes of pre-organization modes along with the changes of the solution acidity. Furthermore, a perfect self-complementary sugar–base hydrogen bond is first reported based on the crystal structure analysis in this work, and different chiralities and SHG activities of CMP–bpe–Mn(II) complexes obtained at different pH values are studied.

Chirality of a nucleotide–Cu(II) complex molecule, [CuNa(GMP)(HGMP)(H2O)7]·6(H2O)·CH3OH (GMP = guanosine 5′-monophosphate), is delivered to the three-dimensional supramolecular architecture by hydrogen bonding. Liquid- and solid-state circular dichroism (CD) spectroscopy are used to analyse the molecular and supramolecular chirality.