Anisotropic temperature factors as mechanism indicators of thermal processes

Abstract

The crystal structures and TG curves of trans-tetrakis(pyrazole)bisisothiocyanatomanganese(II) [(C 3H 4N 2) 4(NCS) 2Mn(II), C2/ c, Z = 4], trans-tetrakis(pyrazole)bisaquamanganese(II)bispyrazolebisnitrate [(((C 3H 4N 2) 4(H 2O) 2Mn(II))(C 3H 4N 2) 2(NO 3) 2), P 1 , Z = 1], trans-hexakis(pyrazole)manganese(II)bisperchlorate [((C 3H 4N 2) 6Mn(II))(ClO 4) 2, P 3 , Z = 1] and trans-tetrakis(pyrazole)bischloromanganese(II) [(C 3H 4N 2) 4(Cl) 2Mn(II), C2/ c, Z = 4] were determined recently. The TG curves point for the first complex to two, for the second to three, for the third to one and for the fourth to two kinds of pyrazole with different bonding strengths in the structures and in accord to the anisotropic temperature factors, coordination (symmetry) and hydrogen bonds. It seems that the anisotropic temperature factor coefficients or their equivalent values, U eq (Å 2), could be used as indicators of the thermal decomposition processes.