Structure determination and bonding properties of gas-phase OPt anion and its neutral form.

Using anion photoelectron spectroscopy and quantum chemical calculations, the structures and properties of OPt are investigated. The vertical detachment energies (VDEs) of OPt are measured to be 3.28 eV and 3.23 eV through the use of 355 and 266 nm photons, respectively. The high experimental VDEs of OPt can be attributed to the strong Pt-Pt and Pt-O σ bonds and low orbital energy of the SOMO. It is found that neutral OPt has an OPt triangular structure with symmetry and A electronic state. In the neutral OPt, the O atom interacts with the Pt moiety by two 2c-2e PtO bonds, one 3c-2e PtO σ bond, and one 3c-2e PtO π bond. On the other hand, anionic OPt adopts a Pt-Pt-O bent structure with symmetry and A' electronic state. NPA and ELF analyses indicate charge transfer upon complexation from the metal atoms to the O atom. Chemical bonding analyses show that OPt have the strong covalent Pt-Pt and Pt-O bonds, and neutral OPt exhibits σ aromaticity and π antiaromaticity.