Spectroscopic Identification of Diphosphene HPPH and Isomeric Diphosphinyldene PPH<sub>2</sub>
Bo Lü, Lina Wang, Xin Jiang, Guntram Rauhut, Xiaoqing Zeng
Abstract
Abstract The simplest diphosphene HPPH and isomeric diphosphinyldene PPH 2 features prototype phosphorus‐phosphorus multiple bonding properties that have been of long‐standing interest in main‐group chemistry. Herein, we report the observation of cis ‐HPPH, trans ‐HPPH, and PPH 2 among the respective laser photolysis products of phosphine (PH 3 ) and diphosphine (P 2 H 4 ) in solid N 2 ‐ and Ar‐matrices at 10 K. The identification of these P 2 H 2 isomers with matrix‐isolation IR and UV/Vis spectroscopy is supported by D‐isotope labeling and the quantum chemical calculations at the CCSD(T)‐F12a/cc‐pVTZ‐F12 level using configuration‐selective vibrational configuration interaction theory (VCI). Bonding analyses suggest that the two conformers of HPPH contain standard PP double bonds, whereas, PPH 2 resembles P 2 in having partial PP triple bond due to the H 2 P←P π bonding interaction.