Structural studies of metal complexes with ω-nitroacetophenone. Crystal structures of bis-(ω-nitroacetophenonato)copper(II), and of its addition complexes with 2- and 4-methylpyridine (α-and γ-picoline)

Abstract

The crystal and molecular structure of bis-(ω-nitroacetophenonato)copper(II)(1) and of its addition complexes, (2) and (3), with α- and γ-picoline (2- and 4-methylpyridine respectively) have been determined and refined by anisotropic least-squares methods to final R values of 0·072, 0·096, and 0·072. Crystal data: (1), triclinic, space group P, a= 5·453 ± 0·01, b= 8·183 ± 0·01, c= 9·506 ± 0·01 Å, α= 109° 55′± 10′, β= 104° 52′± 10′, γ= 90° 21′± 10′, Z= 1; (2), triclinic, space group P, a= 10·537 ± 0·01, b= 8·624 ± 0·01, c= 12·089 ± 0·01 Å, α= 93° 18′± 10′, β= 94° 20′± 10′, γ= 92° 21′± 10′, Z= 2; (3), monoclinic, space group C2/c, a= 19·238 ± 0·010, b= 9·268 ± 0·005, c= 17·710 ± 0·010 Å, β= 120° 5′± 5′, Z= 4. The environment of the copper atom is pseudo-octahedral for (1). The copper atom co-ordination is tetragonal pyramidal for (2) and pseudo-octahedral for (3). The N-bases are co-ordinated on the basal plane of the pyramid in (2) and on the equatorial plane in (3). This causes displacement in the axial position of one of the oxygen atoms for one ligand molecule in (2) and for both the ligand molecules in (3).