Three complexes of bis(N-methylbenzohydroxamato-O,O')copper(II)

Abstract

The first single-crystal studies of three bis-transoid Cu–hydrox­amate salts, bis(3-methoxy-4,N-dimethyl­benzo­hydrox­amato-O,O′)copper(II), [Cu(C10H12NO3)2], bis(4-chloro-N-methyl­benzo­hydro­xamato-O,O′)copper(II), [Cu­(C8­H7­Cl­NO2)2], bis(N-methyl-3,5-di­nitro­benzo­hydro­xamato-O,O′)copper(II)–chloro­form (1/2), [Cu­(C8­H6­N3O6)2]·­2CHCl3, are presented. The Cu atom in each of the title compounds sits at a center of inversion and displays a nearly square-planar geometry with the hydro­xamate-O atoms connected to it in a syn configuration. The N atoms are in a transoid configuration. Each five-membered Cu–hydro­xamate ring is planar, thus providing evidence that a planar N atom is present in each ring. The phenyl groups are twisted with respect to the hydro­xamate group by ∼40–54°. The angular strain of the sp2 carbonyl oxy­gen is significant (∼10° from ideal).