Dicopper(II) complexes of chiral C2-symmetric diamino-bis(2-methylpyridyl) and diamino-bis(2-methylbenzimidazolyl) ligands

Abstract

Reaction of the chiral ligands (1 S ,4 S )-2,5-bis(6-methylpyridyl)-diazabicyclo[2.2.1]heptane ( L 1 ), and (1 S ,4 S )-2,5-bis(2-methylbenzimidazolyl)-diazabicyclo[2.2.1]heptane ( L 2 ) with copper(II) acetate results in the hydroxo-bridged dicopper complexes [( L 1 )Cu 2 (μ-OH)(H 2 O)(OAc) 2 Cl] ( 1-Cl ·H 2 O), and [( L 2 )Cu(μ-OH)(H 2 O)(MeOH)(OAc) 2 ]OAc ( 2 . H 2 O,MeOH). Both chiral complexes were characterized spectroscopically, as well as in the solid state by X-ray crystallography. ► C 2 -symmetric diazabicycle allows preparation of tetradentate ligands. ► Chiral ligands with diamino-bis(pyridine) and diamino-bis(benzimidazole) N 4 donor sets were obtained. ► Reactions with copper(II) acetate result in chiral μ-hydroxo-bridged dicopper complexes. Chiral tetradentate ligands with diamino-bis(2-methylpyridyl) and diamino-bis(2-methylbenzimidazolyl) donor sets react with copper(II) acetate affording chiral bimetallic complexes.