The adducts [MBr(2)(4-cyanopy)(n)] (where M is Mn(II), Fe(II), Co(II), Ni(II), Cu(II), or Zn(II), 4-cyanopy is 4-cyanopyridine, n = 1 or 2) were synthesized and characterized by melting points, elemental analysis, thermal analysis, and IR spectroscopy From calorimetric studies in solution, the standard enthalpies of formation of the adducts and several thermochemical parameters were determined. The mean standard enthalpies of the metal-nitrogen bonds wet e calculated