Jianbo Qin

Reversible color changes of metal(II)-N1,N3-di(pyridin-4-yl)isophthalamide complexes via desolvation and solvation

Four metal(ii)-N(1),N(3)-di(pyridin-4-yl)isophthalamide (L) complexes formulated as [Cu(L)(2)Cl(2)]·5.5H(2)O (1), [Ni(L)(2)Cl(2)]·5.5H(2)O (2), [Co(L)(m-BDC)]·DMF (3) (m-BDC = 1, 3-benzenedicarboxylic dianion) and [Cd(2)(L)(2)(m-BDC)(2)]·DMF·0.2H(2)O (4) have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffractions. Complexes 1 and 2 are isomorphous, both of them exhibit chain-like frameworks, in which ligand L shows a cis-conformation. Complex 3 displays a three dimensional architecture constructed by ligand L with intermediate-conformation linking different chains. Complex 4 shows a corrugated two dimensional layer in which ligand L with trans-conformation and m-BDC act as bridging groups linking different Cd(ii) centers. The four complexes all possess stable host frameworks, and complexes 1-3 show reversible color changes via desolvation and solvation.

A homochiral network constructed by supramolecular packing of 2D chiral bilayer: synthesis, structure and property of metal(II) complex based on achiral 3,3′,4,4′-oxydiphthalate and coligand

Using achiral 3,3′,4,4′-oxydiphthalic acid (H4ODPA) and coligands, four metal(II) complexes formulated as Ni2(ODPA)(4,4′-bpy)2(H2O)4·H2O (bpy = bipyridine) (1), Cu4(H2ODPA)4(2,2′-bpy)4(H2O)2·2H2O (2), Co3(HODPA)2(2,2′-bpy)3(H2O)10·2H2O (3) and Zn2(H2ODPA)(L)2·6H2O (HL = gatifloxacin) (4) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 shows a uninodal 3-connected chiral 2D bilayer with {82.10} topology. Packing of the 2D bilayer leads to the homochiral architecture of complex 1. Complexes 2 and 3 are tetranuclear Cu(II) and mononuclear Co(II) complexes, respectively. Complex 4 shows a chain-like structure. Complex 1 shows strong CD signal, and complexes 2–4 are achiral. The twisted 4,4′-bpy plays an important role in the formation of the chiral complex 1. The supramolecular packing in complex 1 accounts for the chiral space group of the structure. The four complexes show different UV-vis absorption and photoluminescence properties as well as different thermal stability.

Organic molecules induced crystal transformation from a two dimensional coordination polymer to chain-like structures

Using exo-7-oxabicyclo-[2.2.1]-5-heptene-2,3-dicarboxylic acid (H22L), three Mn(II) complexes formulated as [Mn(L)(H2O)]·H2O (1), [Mn2(L)2(H2O)4]·(C6H6O)·5H2O (2) and [Mn(L)(H2O)2]·0.5(C6H6O2) (3) have been synthesized and structurally characterized by single-crystal X-ray diffractions. Complex 1 shows a uninodal 3-connected 2D layer with 63-hcb topology. In complexes 2 and 3, similar alternating left-handed and right-handed helical chains are observed. Complex 1 is transformed into complexes 2 and 3 upon the attack of phenol and hydroquinone, respectively. The centrosymmetric complex 1 is transformed into the acentric complex 2, which is induced by the acentric phenol molecule. L exhibits similar exo-configuration and different coordination modes in the three complexes. Due to the unsymmetrical coordination environments of two carboxylate groups, achiral L possesses four chiral carbon atoms in the three Mn(II) complexes. The three complexes show different photoluminescence properties.

Di-μ-sulfato-κ4O:O′-bis­[diaqua­(1H-imidazo[4,5-f][1,10]phenanthroline-κ2N7,N9)cobalt(II)] dihydrate

In the centrosymmetric dinuclear title compound, [Co2(SO4)2(C13H8N4)2(H2O)4]·2H2O, the CoII atom is coordinated by two N atoms from two 1H-imidazo[4,5-f][1,10]phenanthroline ligands, two O atoms from two sulfate anions and two O atoms from water molecules in a distorted octahedral geometry. The Co⋯Co separation is 5.1167 (7) Å. The coordinated and uncoordinated water molecules engage in N—H⋯O and O—H⋯O hydrogen-bonding interactions.

Bis(μ-3,5-dimethyl-1,2,4-triazol-4-amine-κN:N)bis-[dichlorido-cobalt(II)].

In the centrosymmetric dinuclear compound, [Co2Cl4(C4H8N4)2], the CoII atom is coordinated by N atoms from two 3,5-dimethyl-1,2,4-triazol-4-amine ligands and two Cl atoms in a distorted tetrahedral geometry. A six-membered ring is formed by four N atoms from two ligands and the two CoII centers; the Co⋯Co distance is 3.756 (9) Å.