XPS and quantum chemical investigation of electronic structure of Co complexes with calix[4]arenes modified by R2PO groups in upper or lower rim

Abstract

Interatomic interactions and charge state of atoms in calix[4]arenes functionalized by phosphoryl groups in the upper (L1) and lower (L2) rims, in complexes [Co2(NO3)4*L1], [Co2(NO3)4*L2] and in heterometallic complex [RuNO(NO2)4OH(H2O)Co*L2] have been studied with the methods of quantum chemistry, X-ray photoelectron spectroscopy and static magnetochemistry.According to the experimental and calculated data, the Co atoms are in the oxidation state 2+ for all compounds. The energies and shapes of the Ru(3p3/2)-lines indicate formal oxidation states of Ru(II). Magnetic properties of investigated compounds are characterized by ferromagnetic interaction of high spin Co(II) atoms. Coordination of the Co(NO3)2 fragments by the P = O-groups in the complexes leads to decreasing in the electron density on O and P atoms comparatively to L1 and L2.