QUANTUM-CHEMICAL STUDY OF CHANGES IN THE MAGNETIC STATE OF NI(AA)(2) AND NI(KTF)(2) ADSORBED ON THE SURFACE OF NATURAL SILICA

For nickel(II) bis-acetylacetonate [Ni(AA)(2)] and nickel(II) bis-trif luoroketoiminate [Ni(ktf)(2)], quantum chemical cluster modeling of th e effect of chelate node distortion and changed coordination number of the central atom on the magnetic state of the molecules adsorbed on t he surface of hydrated natural oxide on silicon by the SCF-X-alpha-SW method is reported. Differences between the energies of the lowest sin glet and triplet states are obtained for the clusters. It is shown tha t the diamagnetic state of Ni(ktf)(2) molecules changes to paramagneti c when the coordination number of the central atom increases due to it s donor-acceptor interaction with the Si-O groups of the real surface of silicon provided that the molecules are adsorbed by the planes of t he chelate rings.