Structural, thermal, and magnetic properties of three transition metal-4,4′-bipyridine coordination polymers:: [Ni(4,4′-bipy)3(H2O)2](ClO4)2•1.4(4,4′-bipy)•3(H2O); [Co(4,4′-bipy)3(H2O)2](ClO4)2•1.4(4,4′-bipy)•3(H2O); [Cu(4,4′-bipy)3(DMSO)2](ClO4)2•2(4,4′-bipy)

Three new transition metal coordination polymers based on 4,4'-bipyridine (4,4'-bipy) are reported. The reaction of I equiv. of nickel(II) perchlorate hexahydrate or cobalt(II) perchlorate hexahydrate with 3 equiv. of 4,4'-bipy under inert atmosphere, hydrothermal conditions yields [Ni(4,4'-bipy)(3)(H2O)(2)](ClO4)(2).1.4(4,4'-bipy).3(H2O) (1) and the isostructural [Co(4,4'-bipy)(3)(H2O)(2)](ClO4)(2).1.4(4,4'-bipy).3(H2O) (2), respectively, while the combination of one equivalent of copper(II) perchlorate hexahydrate with three equivalents of 4,4'-bipy under ambient laboratory conditions in dimethyl sulfoxide produces the structurally related [Cu(4.4'-bipy)(3)(DMSO)(2)](ClO4)(2).2(4,4'-bipy) (3). The metal:bipy molar ratio within the framework is 1:3 for each structure. Each sample consists of coordinate covalent metal-(4,4'-bipy) chains that pack through a combination of weaker hydrogen bonding and pi-stacking interactions to form two-dimensional sheets. The sheets in turn pack to form three-dimensional structures with oblique channels that extend throughout the solid and contain enclathrated guest molecules. All three samples are susceptible to loss of enclathrated guest molecules. Magnetic data indicate that each sample behaves essentially Curie-like, with only small exchange coupling (Jlk(B) < 1 K) observed in each case. (C) 2003 Elsevier Ltd. All rights reserved.