Observation of unsaturated platinum carbenes Pt2C2n− (n = 1–3) clusters: A photoelectron imaging spectroscopic and theoretical study.

The structural and bonding properties of the Pt₂C_2n⁻ (n = 1–3) complexes have been investigated by mass-selected photoelectron velocity-map imaging spectroscopy with quantum chemical calculations. The adiabatic detachment energies and vertical detachment energies of Pt₂C_2n⁻ have been obtained from the measured photoelectron imaging spectra. Theoretical results indicate that the lowest-energy isomers of Pt₂C_2n⁻ (n = 1–3) possess linear chain-shaped configurations. The binding motif in the most stable isomer of Pt₂C₂⁻ has a linear cumulenic structure with a Pt=C=C=Pt configuration, and the structural characteristic persists up to all the lowest-energy isomers of the Pt₂C₄⁻ and Pt₂C₆⁻ anions. The chemical bonding analyses indicate that the Pt₂C_2n⁻ (n = 1–3) complexes have multicenter two-electron characteristics. [ABSTRACT FROM AUTHOR]