Cobalt and zinc halide complexes of 4-chloro and 4-methylaniline: Syntheses, structures and magnetic behavior

Jonathan E. Chellali, Clark University
Cailyn Keely, Clark University
Graham Bell, Clark University
Kimberly L. Dimanno, Clark University
Tran Tran, Clark University
Christopher P. Landee, Clark University
Diane A. Dickie, Brandeis University
Melanie Rademeyer, University of Pretoria
Mark M. Turnbull, Clark University
Fan Xiao, Laboratory for Neutron Scattering, Villigen

Abstract

A family of cobalt(II)and zinc(II)compounds with the general formula (4-subC6H4NH2)2MX2, (M = Co, Zn; X = Cl, Br; sub = CH3, Cl)has been prepared and the compounds characterized by single-crystal X-ray diffraction. The eight compounds crystallize in the monoclinic space group I2/a and are isocoordinate, but show different crystal packing for the 4-methyl and 4-chloroaniline complexes as a result of halogen bonding in the 4-chloroaniline family. The cobalt complexes have also been studied via variable temperature magnetic susceptibility measurements. All four Co(II)compounds exhibit antiferromagnetic exchange (maxima in χ are observed)and have been fitted with a 1D-chain model (cobalt chloride complexes, J ∼ −3 K)or a 2D-model (cobalt bromide complexes, J ∼ −4 K). Analysis of potential superexchange pathways is provided.