Crystal and molecular structures and magnetic properties of four new exchange-coupled copper(II) complexes derived from different 3-N,N-dialkylamino-1-propanols and pseudohalogens

Abstract

The crystal and molecular structures of (3-N,N-dimethylamino-1-propanolato) isocyanatocopper(II)(1), (3-N,N-dimethylamino-1-propanolato) isothiocyanatocopper(II)(2), (3-N,N-diethylamino-1-propanolato) isothiocyanatocopper(II)(3), and (3-N,N-di-n-butylamino-1-propanolato)isothiocyanatocopper(II)(4) have been determined using three-dimensional X-ray diffractometer data. Final R values were 0.0237 for (1), 0.0250 for (2), 0.0297 for (3), and 0.0464 for (4). Compounds (1) and (2) crystallize in monoclinic lattices (space group P2₁/c), (3) and (4) in triclinic ones (space group P). The structure of (1) consists of an infinite two-dimensional network of alkoxo-bridged dimers connected by cyanato-groups in the plane (100); the three remaining structures consist of infinite chains of alkoxo-bridged dimers connected by the thiocyanato-groups. Within the dimeric units the copper atoms have distorted square-planar co-ordination. The connection between the dimers leads to a fifth co-ordination with longer copper–ligand bonds. The magnetic susceptibilities measured from 11.1 K show for all four compounds very strong antiferromagnetic spin coupling (|2J| > 850 cm^–1). A correlation between the exchange constants and the Cu–O–Cu′ bridging angles within the dimers for all known (3-N,N-dialkylamino-1-propanolato)-halogenocopper(II) and -pseudohalogenocopper(II) complexes is given and shows that these complexes are systematically more strongly coupled than the related complexes derived from analogous aminoethanols.