			Home About us Contact

Dinuclear Units (dinuclear + unit)

Distribution by Scientific Domains

Chemistry	100%

Selected Abstracts

Poly[bis(,-benzene-1,4-dicarboxylato)bis[,-6-(4-pyridyl)-5H -imidazolo[4,5- f][1,10]phenanthroline]dilead(II)]: an interpenetrating ,-Po net

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2010
Zhan-Lin Xu
The asymmetric unit of the title compound, [Pb2(C8H4O4)2(C18H11N5)2]n, contains two PbII atoms, two benzene-1,4-dicarboxylate (1,4-bdc) dianions and two 6-(4-pyridyl)-5H -imidazolo[4,5- f][1,10]phenanthroline (L) ligands. Each PbII atom is eight-coordinated by three N atoms from two different L ligands and five carboxylate O atoms from three different 1,4-bdc dianions. The two 1,4-bdc dianions (1,4-bdc1 and 1,4-bdc2) show different coordination modes. Each 1,4-bdc1 coordinates to two PbII atoms in a chelating bis-bidentate mode. Each carboxylate group of the 1,4-bdc2 anion connects two PbII atoms in a chelating,bridging tridentate mode to form a dinuclear unit. Neighbouring dinuclear units are connected together by the aromatic backbone of the 1,4-bdc dianions and the L ligands into a three-dimensional six-connected ,-polonium framework. The most striking feature is that two identical three-dimensional single ,-polonium nets are interlocked with each other, thus leading directly to the formation of a twofold interpenetrated three-dimensional ,-polonium architecture. The framework is held together in part by strong N,H...O hydrogen bonds between the imidazole NH groups of the L ligands and the carboxylate O atoms of 1,4-bdc dianions within different ,-polonium nets. [source]

Anion-Directed Template Synthesis and Hydrolysis of Mono-Condensed Schiff Base of 1,3-Pentanediamine and o -Hydroxyacetophenone in NiII and CuII Complexes

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 21 2008
Pampa Mukherjee
Abstract Bis(o -hydroxyacetophenone)nickel(II) dihydrate, on reaction with 1,3-pentanediamine, yields a bis-chelate complex [NiL2]·2H2O (1) of mono-condensed tridentate Schiff baseligand HL {2-[1-(3-aminopentylimino)ethyl]phenol}. The Schiff base has been freed from the complex by precipitating the NiII as a dimethylglyoximato complex. HL reacts smoothly with Ni(SCN)2·4H2O furnishing the complex [NiL(NCS)] (2) and with CuCl2·2H2O in the presence of NaN3 or NH4SCN producing [CuL(N3)]2 (3) or [CuL(NCS)] (4). On the other hand, upon reaction with Cu(ClO4)2·6H2O and Cu(NO3)2·3H2O, the Schiff base undergoes hydrolysis to yield ternary complexes [Cu(hap)(pn)(H2O)]ClO4 (5) and [Cu(hap)(pn)(H2O)]NO3 (6), respectively (Hhap = o -hydroxyacetophenone and pn = 1,3-pentanediamine). The ligand HL undergoes hydrolysis also on reaction with Ni(ClO4)2·6H2O or Ni(NO3)2·6H2O to yield [Ni(hap)2] (7). The structures of the complexes 2, 3, 5, 6, and 7 have been confirmed by single-crystal X-ray analysis. In complex 2, NiII possesses square-planar geometry, being coordinated by the tridentate mono-negative Schiff base, L and the isothiocyanate group. The coordination environment around CuII in complex 3 is very similar to that in complex 2 but here two units are joined together by end-on, axial-equatorial azide bridges to result in a dimer in which the geometry around CuII is square pyramidal. In both 5 and 6, the CuII atoms display the square-pyramidal environment; the equatorial sites being coordinated by the two amine groups of 1,3-pentanediamine and two oxygen atoms of o -hydroxyacetophenone. The axial site is coordinated by a water molecule. Complex 7 is a square-planar complex with the Ni atom bonded to four oxygen atoms from two hap moieties. The mononuclear units of 2 and dinuclear units of 3 are linked by strong hydrogen bonds to form a one-dimensional network. The mononuclear units of 5 and 6 are joined together to form a dimer by very strong hydrogen bonds through the coordinated water molecule. These dimers are further involved in hydrogen bonding with the respective counteranions to form 2-D net-like open frameworks. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Dinuclear Complexes of MII Thiocyanate (M = Ni and Cu) Containing a Tridentate Schiff-Base Ligand: Synthesis, Structural Diversity and Magnetic Properties

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2005
Suparna Banerjee
Abstract A dinuclear NiII complex, [Ni2(L)2(H2O)(NCS)2]·3H2O (1) in which the metal atoms are bridged by one water molecule and two ,2 -phenolate ions, and a thiocyanato-bridged dimeric CuII complex, [Cu(L)NCS]2 (2) [L = tridentate Schiff-base ligand, N -(3-aminopropyl)salicylaldimine, derived from 1:1 condensation of salicylaldehyde and 1,3-diaminopropane], have been synthesized and characterized by IR and UV/Vis spectroscopy, cyclic voltammetry and single-crystal X-ray diffraction studies. The structure of 1 consists of dinuclear units with crystallographic C2 symmetry in which each NiII atom is in a distorted octahedral environment. The Ni,O distance and the Ni,O,Ni angle, through the bridged water molecule, are 2.240(11) Å and 82.5(5)°, respectively. The structure of 2 consists of dinuclear units bridged asymmetrically by di-,1,3 -NCS ions; each CuII ion is in a square-pyramidal environment with , = 0.25. Variable-temperature magnetic susceptibility studies indicate the presence of dominant ferromagnetic exchange coupling in complex 1 with J = 3.1 cm,1, whereas complex 2 exhibits weak antiferromagnetic coupling between the CuII centers with J = ,1.7 cm,1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]