Standard enthalpies of formation of solid complexes of lanthanide nitrates with alanine

The combustion energies of fourteen solid complexes of lanthanide nitrate with alanine were determined. The standard enthalpies of combustion, Delta(c,coor(s))Hdegrees, and standard enthalpies of formation, Delta(f,coor(s))Hdegrees, were calculated for these complexes. The relationship Of Delta(c,coor(s))Hdegrees and Delta(f,coor(s))Hdegrees with the atomic numbers of the elements in the lanthanide series were examined. The results show that a certain amount of covalence is present in the chemical bond between the lanthanide cations and alanine.