Phosphorus Analogues of Methyl Nitrite and Nitromethane: CH3OPO and CH3PO2
Xiaofang Zhao1, Xianxu Chu1, Guntram Rauhut2, Changyun Chen1, Chao Song1, Bo Lu1, and Xiaoqing Zeng1, 2,*（曾小庆）
1 College of Chemistry, Chemical Engineering and Materials Science Soochow University, Suzhou 215123 (China)
2 Institute for Theoretical Chemistry, University of Stuttgart Pfaffenwaldring 55, 70569 Stuttgart (Germany)
3 Department of Chemistry, Fudan University Shanghai 200433 (China)
Angew. Chem. Int. Ed.2019, 58, 12164--12169
Methoxyphosphinidene oxide (CH3OPO) and isomeric methyldioxophosphorane (CH3PO2 ) are key intermediates in the degradation of organophosphorus compounds (OPCs). Unlike the nitrogen analogues CH3ONO and CH3NO2 , the experimental data for these two prototypical OPCs are scarce. By high-vacuum flash pyrolysis (HVFP) of the diazide CH3OP(O)(N3)2 at 1000 K, the cis and trans conformers of CH3OPO have been generated in the gas phase and subsequently isolated in cryogenic Ar and N2 matrices for IR spectroscopic characterization. Upon 266 nm laser irradiation of CH3OPO, cis!trans conformational conversion occurs with concurrent isomerization to CH3PO2 . The spectroscopic identification of CH3OPO and CH3PO2 is supported by D-, 13C-, and 18O-isotope labeling and quantum chemical calculations at the CCSD(T)-F12a/cc-pVTZ-F12 level using configuration-selective vibrational configuration interaction (VCI).