The Charge State of Pt in Binary Compounds and Synthetic Minerals Determined by X-ray Absorption Spectroscopy and Quantum Chemical Calculations

The binary synthetic compounds of Pt with chalcogens (O, S, Se, Te), pnictogens (As, Sb, Bi), and intermetallic Ga, In, Sn various stoichiometry were studied via X-ray absorption spectroscopy (XAS). partial atomic charges in the computed using quantum chemical density functional theory (DFT) based methods: Bader (QTAIM) method, density-derived electrostatic (DDEC6) approach. Strong positive correlations established between calculated electronegativity (?) ligands. charge PtL2 increases much sharply when ligand than PtL compounds. effect ligand-to-Pt ratio on depended electronegativity. DDEC6 growth number ligands PtSn (n = 1, 2; ?(S) >> ?(Pt)), weakly depends phase composition PtTen ?(Te) is slightly lower decreases (becomes more negative) increase electron donors (?(L) < ?(Pt), L Sn). According to XANES spectroscopy, 5d (L2,3 edges) 6p (L1-edge) electrons at site decreased increased chalcogenides pnictides groups. An resulted L3-edge white line intensity area all In case pnictides, this behavior was consistent rule as it indicated a loss caused by ligands, i.e., acceptors electrons. However, ligands–electron (Te, Sn, In) observation apparent contradiction arguments indicates 5d-shell vacancies (holes) for which opposite trend expected. This can be explained framework compensation model. d-electrons low (?(Pt) > ?(L)) overcompensated gain hybridized s-p density, confirmed L1 - edge spectra analysis. As result, total followed rule, ligands-electron donors. empirical parameters spectral features used identify state pyrite, applied determine other ore minerals.