Rf. De Farias et C. Airoldi, Calorimetric study of ethyleneurea, ethylenethiourea and propyleneurea cadmium chloride adducts, THERMOC ACT, 378(1-2), 2001, pp. 113-116
Adducts of the general formula CdCl2. nL [n = 1 and 2; L = ethyleneurea (eu
), ethylenethiourea (etu) and propyleneurea (pu)] were synthesized by a sol
id state route and characterized by elemental analysis, infrared spectrosco
py, and reaction solution calorimetry. The infrared results showed that eu
and pu coordinate through carbonylic oxygen atoms, whereas etu uses the nit
rogen as coordinating site. The standard molar reaction enthalpy in condens
ed phase: CdCl2(c) + nL(c) = CdCl2. nL(c); Delta H-r(m)0, were obtained fro
m reaction-solution calorimetry, to give the following values for mono and
bisadducts: -20.0 +/- 0.1; -19.9 +/- 0.1; -13.3 +/- 0.1 and -38.6 +/- 0.1;
-56.9 +/- 0.1; -17.0 +/- 0.1 kJ mol(-1) for eu, etu and pu, respectively. T
he values of decomposition (Delta H-D(m)theta) and lattice enthalpy (Delta
H-M(m)theta) as well as the mean cadmium-ligand bond dissociation enthalpy,
D (Cd-L), were calculated for all adducts. (C) 2001 Elsevier Science B.V.
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