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

Abstract

Abstract A dinuclear Ni II complex, [Ni 2 ( L ) 2 (H 2 O)(NCS) 2 ] · 3H 2 O ( 1 ) in which the metal atoms are bridged by one water molecule and two μ 2 ‐phenolate ions, and a thiocyanato‐bridged dimeric Cu II 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 C 2 symmetry in which each Ni II 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‐μ 1,3 ‐NCS ions; each Cu II ion is in a square‐pyramidal environment with τ = 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 Cu II centers with J = –1.7 cm –1 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)