Zhong-Ning Chen

Cyano-bridged extended heteronuclear supramolecular architectures with hexacyanoferrates(II) as building blocks

Abstract Two cyano-bridged heteronuclear coordination polymers [{Cu(bipn)} 3 Fe(CN) 6 ] n (ClO 4 ) 2 n ·4 n H 2 O (bipn=bis(3-aminopropyl)amine) ( 1 ) and [{Cd(tet)} 2 Fe(CN) 6 ] n ·3 n H 2 O (tet=triethylenetetramine) ( 2 ) were synthesized and their structures determined. Both complexes were obtained from the assembly reactions of [ML n ] 2+ (M=Cu, Cd; n =1, 2) and [Fe(CN) 6 ] 4− in aqueous solutions. Complex 1 exhibits a honeycomb structure with twisty rings formed by Cu(II), Fe(II), and cyanides. The anions ClO 4 − weakly coordinate to Cu(II) and form hydrogen bonds with amino groups of bipn, while water molecules link to the 2D network via hydrogen bonds. In complex 2 , the neutral polymer [{Cd(tet)} 2 Fe(CN) 6 ] n forms zigzag chains. The water molecules insert between chains and pull them together to form a layered structure via a series of interchain hydrogen bonds. Thermal analyses over the temperature range 30–700°C show both complexes decompose completely above 460°C.

Function of the hydrogen bond in the conversion of α- to β-Mo8O264− ions: Formation and structure of tetra(tributylhydrogenammonium) β-octamolybdate

Abstract Complex β-(Bu3NH)4Mo8O26 has been transformed from α-(Bu4N)4Mo8O26 in the presence of o-mercaptophenol (H2mp) and CuCl2 in MeOH, and structurally characterized. It can be considered as a dimer [(Bu3NH)2Mo4O13]2 with a center of symmetry. Each molybdenum atom is in a severely distorted octahedral environment. Two types of H bond between the cations and the anions have been found in the complex: N–H⋯O and C–H⋯O, which may play important roles in the α→β transformation.

A trinuclear nickel(II) complex with alternating square-planar and octahedral geometries. Synthesis, crystal structure and magnetic properties of [Ni3(oxen)2(en)][ClO4]2

Abstract The reaction of Ni(oxen)[oxen = N , N ′-bis(2-aminoethyl)oxamido dianion], NiCl 2 and the disodium salt of EDTA (ethylenediamine tetraacetic acid) in 1:1:1 molar ratio gave the trinuclear complex [Ni 3 (oxen) 2 (en)][ClO 4 ] 2 (en = 1,2-ethylenediamine), where en came from the partial decomposition of oxen. The complex exhibits a curved Ni 3 metal arrangement with the angle Ni(2)ue5f8Ni(1)ue5f8Ni(2a) of 119.0°. The structure consists of a Ni 3 II unit with three nickel(II) atoms chelated and bridged by two oxamidato (oxen) groups in cis -conformation. The central nickel atom has a distorted octahedral geometry whereas the two on the sides have square-planar surroundings. The complex is paramagnetic and its magnetic behaviour can be interpreted by single-ion anisotropy with D = 5.22 cm −1 and m s = 0 singlet ground state.

Syntheses and X-ray structural characterization of phosphine cobalt(II) complexes with 2-mercaptobenzothiazole

Abstract Mononuclear cobalt(II) complexes Co(mbt-N)2(PBu3n)2 (1) (Hmbt = 2-mercaptobenzothiazole; PBu3n = tri-n-butyphosphine) and Co(mbt-S, N)2(dppe)·MeCN (2) [dppe = 1, 2-bis(diphenylphosphino) ethane] were synthesized and characterized by X-ray crystallography, IR and EPR spectra, cyclic voltammetric data and magnetic susceptibility measurements. The Co atom in (1) exhibits an approximate square-planar geometry with the heterocyclic N-donors from mbt bonding to the cobalt atom in a monodentate mode. Complex (2) has a distorted octahedral environment of Co with both the exocyclic-S and the hetero-N donors of mbt bound to the cobalt atom in a bidentate chelating mode. The Co atom in both complexes shows spin state of S =3/2 with μeff of 4.25 and 4.40μB for 1 and 2, respectively.

2D hexagonal grids assembled into 3D nets via Ag···Ag interactions

AbstractA three-dimensional coordination polymer [Ni(en)2Ag3(CN)5]n (en = 1,2-diaminoethane) was synthesized and characterized by X-ray crystallography. It crystallizes in the triclinic space group n

Supramolecular Architectures Based on trans -Oxamidato-Bridged Copper(II) Synthons and Intramolecular Synergism

Pbar 1

Supramolecular architectures from the self-assembly of trans-oxamidato-bridged dicopper(II) building blocks and phenyldicarboxylates

n,a = 7.520(2) Å, b = 8.194(2) Å, c = 8.426(2) Å, α = 65.35(3)°, β = 69.57(3)°, γ = 68.91(3)°, V = 428.0(2), Å3Z = 1. The 2D hexagonal grids are constructed using cyanides as bridges, and the Ag···Ag interactions between layers lead to a three-dimensional network.

2D structure with rectangular grids woven by coordination chains and pseudo-metal wires

Mono-, di-, tri-, and tetra-nuclear cobalt (iron) complexes containing co-ligands phosphine and thiolate are presented according to the classification by combination of different dentates of the two ligands. Emphasis is being put on the triand tetranuclear cluster complexes of monodentate phosphines and 1,2-bidentate thiolates. These complexes are considered to be constructed based on the general structural fragment (or building block) ML2L′ (L=1,2-bidentate thiolate,L′=tertiary phosphine). Structural regularities are presented in Tables I, III, IV, and V and discussed. FAB mass spectroscopic data showed the possible fragmentation patterns. Synergism of the cluster skeletons is proposed to explain the occurrence of the distinct structural modes.