Solvent-Induced Change of Electronic Spectra and Magnetic
Susceptibility of Co<sup>II</sup> Coordination Polymer with 2,4,6-Tris(4-pyridyl)-1,3,5-triazine
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Abstract
One-dimensional coordination polymer
[Co(Piv)<sub>2</sub>(4-ptz)(C<sub>2</sub>H<sub>5</sub>OH)<sub>2</sub>]<sub><i>n</i></sub> (compound <b>1</b>, Piv<sup>–</sup> = pivalate, 4-ptz
= 2,4,6-tris(4-pyridyl)-1,3,5-triazine) was synthesized by interaction
of Co<sup>II</sup> pivalate with 4-ptz. Desolvation of <b>1</b> led to formation of [Co(Piv)<sub>2</sub>(4-ptz)]<i><sub>n</sub></i> (compound <b>2</b>), which adsorbed N<sub>2</sub> and H<sub>2</sub> at 78 K as a typical microporous sorbent. In contrast,
absorption of methanol and ethanol by <b>2</b> at 295 K led
to structural transformation probably connected with coordination
of these alcohols to Co<sup>II</sup>. Formation of <b>2</b> from <b>1</b> was accompanied by change of color of sample from orange
to brown and more than 2-fold decrease of molar magnetic susceptibility
(χ<sub>M</sub>) in the temperature range from 2 to 300 K. Resolvation
of <b>2</b> by ethanol or water resulted in restoration of spectral
characteristics and χ<sub>M</sub> values almost to the level
of that of <b>1</b>. χ<sub>M</sub><i>T</i> versus <i>T</i> curves for <b>1</b> and samples, obtained by resolvation
of <b>2</b> by H<sub>2</sub>O or C<sub>2</sub>H<sub>5</sub>OH,
were fitted using a model for Co<sup>II</sup> complex with zero-field
splitting of this ion