Mass spectrometric study of the vaporization of N,N′-o-phenylene-bis(salicylideniminate) nickel(II), copper(II), and zinc(II) and N,N′-ethylene-bis(salicylaldiminate) zinc(II) complexes

Abstract

The thermodynamics of vaporization of Ni(saloph), Cu(saloph), Zn(saloph), and Zn(salen) complexes are studied by Knudsen effusion method with mass spectrometric control of the vapor compo sition. It is noted that in the mass spectra of Zn(saloph) and Zn(salen), there are low intensity peaks cor responding to ions of dimer. The effect of the nature of a metal and a ligand on the behavior of fragmenta tion of the complexes during their ionization with electrons is discussed. The enthalpies of sublimation, (T), are calculated by second law of thermodynamics: Ni(saloph) (502-578 K), 163 ± 1 kJ/mol; Cu(saloph) (475-550 K), 162 ± 1 kJ/mol; Zn(saloph) (571-637 K), 176 ± 4 kJ/mol; Zn(salen) (568-634 K), 169 ± 2 kJ/mol.