Zhenghe Peng

Spectroscopic and theoretical studies on copper(II) complex of maleinitriledithiolate and 1,10-phenanthroline

A complete vibrational spectra analysis of the title complex is performed in this paper. The molecular geometry, binding, electron structure and spectroscopic properties for the title complex are studied in detail by PM3 or ZINDO/S method. It has been found that this complex has a planar structure belonging to the symmetry point group C2v and its ground state is the spin doublet state. By comparison with the observed results, it can be concluded that PM3 methods are reliable to calculate the vibrational spectra of this molecule. It is worth noting that the scientific method of assigning vibrational spectra for a complicated molecule containing metal is established herein for the first time by giving main fixed points and pivotal vibrational units. Besides the regular symbols, the new defined symbols eta and M play an important role in describing the vibrational modes accurately and vividly.

Hexamine copper(II) coordination polymers: synthesis, structure and magnetic properties

Four new one-dimensional (1D) polymeric complexes, {[Cu4(L1)2(µ-Br)2(µ4-CO3)]Br(ClO4)3·3H2O}n (1), {[Cu2L2(µ-Cl)Cl2] (ClO4)2·H2O}n (2), {[Cu2L3(µ-Cl)2](ClO4)2}n (3), and {[Cu2L4(µ-Cl)2](ClO4)2}n (4), have been synthesized and characterized, where L1 = N,N,N′,N′-tetrakis(3′-aminopropyl)-1,3-propylenediamine, L2 = N,N,N′,N′-tetrakis(2′-aminoethyl)-1,3-propylenediamine, L3 = N,N,N′,N′-tetrakis(2′-aminoethyl)-1,4-butylenediamine, L4 = N,N,N′,N′-tetrakis(2′-aminoethyl)-1, 6-hexylenediamine. X-Ray structure analysis revealed that the polymeric complexes, created by the bridging groups which are exhibited in the formula, present different 1D coordination motifs: double-stranded chains with voids of 43.5 A2 for 1, sigmoid chains for 2, zigzag chains for 3 and 4 with different coordination polyhedra. Various hydrogen bonding interactions such as N–H⋯Cl, N–H⋯O, C–H⋯Cl, N–H⋯Br and O–H⋯Br join the polymeric chains to generate two-dimensional networks with bigger voids. Magnetic susceptibility data were fitted according to the molecular structures using Hamiltonians: H = −2J1(S2S3 + S1S4) − 2J2(S2S1) − 2J3(S1S3 + S2S4) − 2J4(S3S4), which corresponds to a rectangular array of spins for 1, and H = −2JS1S2 corresponds to a dinuclear array of spins for 2, 3 and 4. It was found that the coupling constants of 1 are −60, −113, −54 and −11 cm−1, and those of 2, 3, and 4 are −2.46, −1.56 and −0.15 cm−1, respectively.

Synthesis and crystal structure of maleonitriledithiolate metal complexes with N-methylacridine as cations

Abstract The synthesis of [N-MeA]2[M(mnt)2] (N-MeA=N-methylacridine; M=Ni (II), Zn (II), Cu (II) and Cd (II); mnt=maleonitriledithiolate) and crystal structure analysis of the Ni (1) and Zn (2) complexes are reported. The conductivities of almost all the complexes under 4 MPa pressure are above 10−5 S cm−1, which are characteristic of intrinsic semi-conductors. The complexes exhibit charge transfer transitions in both their absorption spectra and fluorescence spectroscopy.

A tetranuclear copper(II) complex: crystal structure, assembly, EPR, electrochemistry and magnetism

A tetranuclear copper(II) complex, [Cu2L]2(ClO4)2 · 4H2O (1), where H3L = N,N′-bis(4-(3′-formyl-5′-chlorosalicyclidene)iminoethyl)-4-chloro-2,6-bimethyliminophenol, has been synthesized and structurally characterized by ES-MS, IR and X-ray crystallography. The complex is a dimer of two dinuclear copper(II) acylic enantiomorph subunits ([Cu2L]ClO4 · 2H2O), held together by π–π, coordination and hydrogen bond interactions. The Cu–Cu separation in each subunit, bridged by one phenoxide, is 3.228 Å, and the shortest distance of Cu–Cu between the two subunits is 3.252 Å. There are two crystallographically unique copper(II) environments, one (Cu1) is square-based pyramidal with O3N2 donor set, another (Cu2) square planar with O2N2 donor set. The cyclic voltammogram of the complex shows that it undergoes two stepwise reduction processes, E pc = −0.707 and −0.850 V, respectively. Magnetic measurements in the 2–300 K range indicate strong antiferromagnetic interactions between Cu(II) ions in each subunit with the exchange constant J = −211(2) cm−1. The observation has been rationalized on the basis of the effective magnetic pathway.

Synthesis, X-ray crystal structure and electrochemical properties of (dithiolato)(diimine)copper(II) complexes: [Cu(mnt)(phen)] n and [Cu(dmit)(phen)] 2

Copper (II) complexes [Cu(dmit)(phen)]2 (1) and [Cu(mnt)(phen)] n (2) (mnt2− = maleonitriledithiolate, dmit2− = 1,3-dithiole-2-thione-4,5-dithiolate, phen = 1,10-phenanthroline) have been prepared by ligand-exchange between phen and [N(Bu)4]2[Cu(dmit)2] or [N(Bu)4]2[Cu(mnt)2]. Both complexes have been characterized by spectroscopic, electrochemical, and single-crystal X-ray analysis. In complex 1, dimers are extended into a two-dimensional array by weak S5–Cu contacts. In complex 2, monomers are extended into chains in a head-to-tail arrangement by weak Cu–S coordination bonds and π–π stacking interactions.

A novel low symmetry sulfur containing porphyrazine: synthesis and its interaction with serum albumin

A novel low symmetry sulfur-containing porphyrazine, 5,23,28,32-octabutoxy-10,11,17,18-tetrahydro-[9,12,16,19]-tetrathiino-33H, 35H-dinaphtho-porphyrazine (OTTDP), was synthesized by mixed condensation and characterized by NMR, FAB-MS and UV-visible spectra; this complex was found to be low aggregation in organic solvents and can interact with the serum albumin at several binding sites.