Thermochemistry of 3-Cyanopyridine Adducts of Some Bivalent Transition Metal Bromides

Abstract

The adducts [MBr2(3-cyanopy) n ] (where M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), or Zn(II); 3-cyanopy = 3-cyanopyridine; n = 4 or 2) were synthesized and characterized by melting points, elemental analysis, thermal studies, and IR and electronic spectroscopy. From calorimetric studies in solution, their standard enthalpies of formation and several other thermochemical parameters have been determined. The mean standard enthalpies of the metal–nitrogen bonds were calculated as well as the enthalpies of the adduct formation in the gaseous phase.

Síntese e termoquímica de adutos de brometos de metais bivalentes com aminas hetrocíclicas

“…Aplicando-se a lei de Hess, tem-se a seguinte expressão: b Ref. [58] c Ref. [93] Empregando-se os valores de variação entálpica padrão reticular para os adutos do ligante 3-cianopiridina, obtem-se a seguinte ordem de estabilidade termodinâmica: Ao se aplicando a lei de Hess ao ciclo acima, obtemos:…”