More crystal field theory in action: the metal-4-picoline (pic)-sulfate [M(pic) x ]SO 4 complexes (M = Fe, Co, Ni, Cu, Zn, and Cd)

• Published in: Acta crystallographica. Section C, Structural chemistry Structural chemistry, 2019-05, Vol.75 (Pt 5), p.568-574
• Main Authors: Pham, Duyen N K, Roy, Mrittika, Kreider-Mueller, Ava, Golen, James A, Manke, David R
• Format: Article
• Language: English
• ISSN: 2053-2296; 2053-2296
• DOI: 10.1107/S2053229619004625

Seven crystal structures of five first-row (Fe, Co, Ni, Cu, and Zn) and one second-row (Cd) transition metal-4-picoline (pic)-sulfate complexes of the form [M(pic) ]SO are reported. These complexes are catena-poly[[tetrakis(4-methylpyridine-κN)metal(II)]-μ-sulfato-κ O:O'], [M(SO )(C H N) ] , where the metal/M is iron, cobalt, nickel, and cadmium, di-μ-sulfato-κ O:O-bis[tris(4-methylpyridine-κN)copper(II)], [Cu (SO ) (C H N) ], catena-poly[[bis(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ O:O'], [Zn(SO )(C H N) ] , and catena-poly[[tris(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ O:O'], [Zn(SO )(C H N) ] . The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of M ions adopting an octahedral N O coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the Cu ions possessing square-pyramidal N O coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of Zn ions adopting a tetrahedral N O coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of Zn ions adopting a trigonal bipyramidal N O coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.