SYNTHESIS, CRYSTAL-STRUCTURE AND THERMAL-STABILITY OF THE MGCL2 FORMAMIDE ADDUCT

The reaction of alpha-MgCl2 with formamide affords the MgCl2(HCONH2)6 adduct which was obtained as crystals suitable for X-ray analysis. M(r) = 730.91, monoclinic, space group P2(1)/a with a = 9.199(4), b = 7.413(2), c = 12.227(6) angstrom, alpha = 90.00, beta = 91.5(l), gamma = 90.00-degrees, V = 833.5(6) angstrom3, D(x) = 1.46 g cm-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 4.17 cm-1, F(000) = 380, T = 298 K; observed reflections 1198, R = 0.048, R(w) = 0.047. Such adduct shows a three-dimensional polymeric structure formed through hydrogen bonds between the -NH2 groups and the chloride ions. Each magnesium atom appears to be octahedrally coordinated by six formamide molecules through the carbonyl oxygen atom. The thermal stability of the adduct has also been investigated by thermogravimetric analysis and the obtained TG curve shows that the thermal elimination of the coordinated Lewis base appears to be the result of more than one step.