Metal complexes of quadridentate Schiff bases which can form a four-membered chelate ring
摘要:
The metal complexes of deprotonated N,N'-bis(2-hydroxybenzylidene) arylmethanediimines show a strong preference for tetrahedral structures. Oxidation of the Co(II) derivatives gives compounds with S = 1. (C) 1997 Elsevier Science S.A.
Novel copper(II) complexes of “short” salen homologues. Structure and magnetic properties of the tetranuclear complex [Cu2(L2)2]2 [H2L2 = phenyl-N,N ′-bis(salicylidene)methanediamine] †
Copper(II) complexes of Schiff bases derived from the condensation of two molecules of salicylaldehyde and methanediamine (L1) or some phenyl substituted methanediamines (L2âL5) have been synthesized and characterised. The crystal structure of the phenylmethanediamine (L2) derivative has been determined. The ligand acts as bis-bidentate, bridging two copper atoms which are co-ordinated to two phenolato and two imino groups of two ligands. Two binuclear moieties [Cu2(L2)2] are held together through CuâO(phenolato) interactions between adjacent units forming a pseudo-linear [Cu2L22]2 cluster. Variable temperature magnetic susceptibility data for this derivative reveal the presence of weak antiferromagnetic interactions (âJ â 2â3 cmâ1) between nearest neighbour spin centres. The structural factors that may be responsible for the sign and magnitude of the exchange interactions are discussed.