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

摘要

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 Co(II) pivalate with 4-ptz. Desolvation of 1 led to formation of [Co(Piv)(2)(4-ptz)]n (compound 2), which adsorbed N-2 and H-2 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 Co(II). 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 (chi(M)) in the temperature range from 2 to 300 K. Resolvation of 2 by ethanol or water resulted in restoration of spectral characteristics and chi(M) values almost to the level of that of 1. chi T-M versus T curves for 1 and samples, obtained by resolvation of 2 by H2O or C2H5OH, were fitted using a model for Co(II) complex with zero-field splitting of this ion.