Hai-Bin Zhu

Construction of a metal–organic framework by octuple intercatenation of discrete icosahedral coordination cages

Solvothermal reaction of the H3BTTC (benzo-(1,2;3,4;5,6)-tris(thiophene-2′-carboxylic acid)) ligand with Pb(NO3)2 produced a unique 3-D polycatenated architecture that was constructed by octuple intercatenation of discrete icosahedral coordination cages.

Copper coordination complexes of bis(4-(pyridin-2-yl)pyrimidin-2-ylthio)methane with in situ metal redox reactions

Five copper coordination complexes 1–5 with 2-bppm (2-bppm = bis(4-(pyridin-2-yl)pyrimidin-2-ylthio)methane) have been prepared and structurally elucidated. Complexes 1 and 2 are both discrete dinuclear [2 + 2] macrocyclic structures, simultaneously formed in one-pot reaction with Cu(NO3)2 with in situ reduction of Cu2+. Similarly, dinuclear [2 + 2] macrocyclic motifs are found with 3 and 4, which are also obtained by one-pot reaction but with CuCl accompanied by in situ air oxidation of Cu+. Compound 5 exhibits a 1-D chain structure with 2-bppm and Cu2I2 connected one by one. Luminescence is measured for 2, 4, and 5, all based on d10-closed shell Cu(I).

Metal-directed self-assembly of M3L2 (M=Zn, Cd) metal-organic architectures with a tripodal tris-bidentate chelator

Two discrete M3L2 metal-organic architectures, 1 and 2, have been constructed by reaction of a newly designed tripodal tris-bidentate ligand L with M(NO3)2 (1: M=Zn; 2: M=Cd). Both complexes together with L have been structurally elucidated by single-crystal X-ray crystallography. Complex 1 exhibits a cationic M3L2 coordination architecture bearing three positive charges balanced by three uncoordinated nitrates, while 2 shows a neutral M3L2. 1 and 2 both adopt a compressed trigonal prism shape but show no internal cavity due to close ligand-to-ligand interactions. They display totally different intermolecular packing modes in the solid state, which strongly influence the intermolecular π–π interactions. Complex 1 has been arrayed such that each M3L2 is surrounded by three neighboring C 3-symmetry related ones, whereas 2 exhibits a columnar molecular stacking. The distinctive intermolecular packing modes in the solid state between 1 and 2 bring about a small but discernible red shift (4 nm) corresponding to the π–π ∗ electronic absorption.

A 2-D coordination polymer with Cu4 IS4-core as joints

A coordination polymer based on copper(I) and a heterocyclic thione ligand, HPPT4 (HPPT4 = 4-pyridin-4-yl-pyrimidine-2-thiol) has been prepared. The compound C21H19Cu2N7OS2 (1) has a 2-D polymeric structure with -core as joints linked by μ-thiolate bridges. Crystal data for compound 1: Monoclinic, space group C2/c, a = 22.346(14) Å, b = 15.649(10) Å, c = 13.588(9) Å, β = 97.183(12)°, V = 4714(5) Å3, and Z = 8. Compound 1 displays multiple emissions with maximum wavelength at 391 and 469 nm under photoexcitation at 340 nm.

4,4′-Di-3-pyridyl-2,2′-dithio­dipyrimidine

The asymmetric unit of the title compound, C18H12N6S2, contains one half-molecule situated on a twofold rotational axis that passes through the mid-point of the S—S bond. In the molecule, the C—S—S—C torsion angle is 81.33 (7)°. The crystal packing exhibits no significantly short intermolecular contacts.

A comparative study of coordination architectures constructed by di[4-(pyridin-3-yl)pyrimidinyl]disulfide and different metal salts: crystal structures and luminescence properties

Assembly of di[4-(pyridin-3-yl)pyrimidinyl]disulfide (3-ppds) with different metal salts resulted in a variety of coordination polymers that were structurally elucidated. For MnCl2, a 1-D repeated rhomboidal chain structure [MnCl2(3-ppds)2]n (1) was obtained, whereas a 1-D helical chain structure [Zn(NO3)2(3-ppds)]n (2) was built from Zn(NO3)2. A 1-D zigzag chain structure [Cu2(OAc)4(3-ppds)]n (3) was produced from Cu(OAc)2. In all three complexes, the 3-ppds ligand plays the same role as a bis(monodentate) bridging linker but with variations in both C–S–S–C torsion angles and dihedral angles defined by its conjugated heteroaromatic rings (pyrimidine and pyridine). The luminescence properties of the complexes have been evaluated in the solid state.

A robust polyoxometalate-templated four-fold interpenetrating metal–organic framework showing efficient organic dye photodegradation in various pH aqueous solutions

A Keggin-type polyoxometalate (POM)-templated metal-organic framework, [Cd(TTPB-4)(DMF)3]4[PMo12O40]2[HPMo12O40]·6DMF·4H2O (1), based on a newly designed linker of TTPB-4 [TTPB-4 = 1,3,5-tris(4-(4H-1,2,4-triazol-4-yl)phenyl)benzene], has been hydrothermally synthesized and characterized using IR, XRD, TGA, UV-Vis and photoluminescence spectra. Single-crystal X-ray crystallography reveals that 1 represents a unique POM-templated four-fold interpenetrated 3-D coordination network. The POM-templated MOF of 1 exhibits strong chemical stability that can withstand aqueous solutions of various pH-values (2-10). Particularly, 1 possesses excellent photodegradation activity and recyclability towards the organic dyes of Crystal Violet (CV) and Basic Red 2 in aqueous solutions with different pH values.

Assembling Isomeric heterocyclic disulfide ligands with copper(I) iodide: effect of ligand structure on their assembly structures and S–S reactivity

Self-assembly of two isomeric heterocyclic disulfide ligands, n-ppds (n-ppds = di[n-(pyridin-2-yl)pyrimidinyl]disulfide, n = 3, 4), with copper(I) iodide in acetonitrile/toluene produced different assembled structures and S–S reactivity, exhibiting profound influence of disulfide structure. For 3-ppds, a 2D layered structure 1 based on [CuI(3-ppds)]2 was obtained. Homolytic cleavage of the S–S bond occurred in 4-ppds, resulting in a 1D staircase double-chain structure 2. 1 and 2 have been characterized by single-crystal X-ray diffraction; solid-state diffuse-reflectance UV–vis spectra show that 1 and 2 are semiconductors with band gaps of 2.88 and 2.16 eV, respectively.

{Bis[4-(2-pyrid­yl)pyrimidin-2-yl]sulfane}dichloridocobalt(II)

The asymmetric unit of the title compound, [CoCl2(C18H12N6S)], contains one half-molecule situated on a twofold rotation axis which passes through the Co and S atoms. The metal centre is in a distorted octahedral CoCl2N4 coordination with the Cl atoms in the axial positions. In the crystal structure, intermolecular C—H⋯Cl interactions help to establish the packing.

Tetra­aqua­bis{2-[4-(3-pyrid­yl)pyrimidin-2-ylsulfan­yl]acetato}manganese(II) dihydrate

In the title compound, [Mn(C11H8N3O2S)2(H2O)4]·2H2O, the MnII ion lies on an inversion centre and is coordinated by four water molecules in equatorial positions and two N atoms from two 2-[4-(3-pyridyl)pyrimidin-2-ylsulfanyl]acetate ligands in the axial positions. The water molecules, including the uncoordinated water molecules, and the acetate O atoms are involved in O—H⋯O and O—H⋯N hydrogen-bonding interactions, which link the components into layers parallel to the a (b + c) plane.