X-ray crystal structures, spectroscopic and magnetic measurements of dinuclear alkoxo-bridged copper(II) compounds with substituted bis(2-benzimidazolyl)alkane ligands. First X-ray structure of a copper(II) dinuclear propoxo-bridged compound

Abstract

The synthesis and characterization of three new alkoxo-bridged dinuclear copper(II) compounds are described, all having the general formula [Cu 2(L) 2(RO −) 2](ClO 4) 2(ROH) y (H 2O) z , in which L=b2b (bis(2-benzimidazolyl)-2-butane) and b3b (bis(2-benzimidazolyl)-3-butane), ROH=MeOH, EtOH, 1-PrOH, y=1 or 2, z=0 or 3. The X-ray structure has been solved from two compounds; [Cu 2(b2b) 2(OCH 3) 2](ClO 4) 2(CH 3OH) 2(H 2O) 3 ( 1) and from compound [Cu 2(b3b) 2(C 3H 7O) 2](ClO 4) 2(C 3H 7OH) 2 ( 3). These two compounds consist of dinuclear Cu(II) units with bridging methoxo group for 1 and an unique bridging propoxo group for 3 with two ligands linked to each copper via N, providing square–planar CuN 2O 2 chromophores. The latter one is the first dinuclear Cu(II) X-ray structure with bridging propoxo groups. Both dinuclear compounds are diamagnetic.