Solvent-Induced Change of Electronic Spectra and Magnetic Susceptibility of Co^II Coordination Polymer with 2,4,6-Tris(4-pyridyl)-1,3,5-triazine

One-dimensional coordination polymer [Co­(Piv)2(4-ptz)­(C2H5OH)2]n (compound 1, Piv– = pivalate, 4-ptz = 2,4,6-tris­(4-pyridyl)-1,3,5-triazine) was synthesized by interaction of CoII pivalate with 4-ptz. Desolvation of 1 led to formation of [Co­(Piv)2(4-ptz)]n (compound 2), which adsorbed N2 and H2 at 78 K as a typical microporous sorbent. In contrast, absorption of methanol and ethanol by 2 at 295 K led to structural transformation probably connected with coordination of these alcohols to CoII. Formation of 2 from 1 was accompanied by change of color of sample from orange to brown and more than 2-fold decrease of molar magnetic susceptibility (χM) in the temperature range from 2 to 300 K. Resolvation of 2 by ethanol or water resulted in restoration of spectral characteristics and χM values almost to the level of that of 1. χMT versus T curves for 1 and samples, obtained by resolvation of 2 by H2O or C2H5OH, were fitted using a model for CoII complex with zero-field splitting of this ion.