Energetic Properties and Electronic Structure of [C,N,O,P] and [C,N,S,P] Isomers

Correlated molecular orbital theory at the coupled cluster CCSD­(T) level with augmented correlation consistent basis sets including F12 explicit correlation has been used to predict the structure and energetic properties of the isomers of [C,N,O,P] and [C,N,S,P]. The predicted ground states are the species derived from a trivalent P with a PO or PS bond and a cyano group bonded to the P. The other low energy isomers are the isonitriles and they are 1.4 kcal/mol and 6.6 less stable than the ground state for PO and PS, respectively. An analysis of the bond energies is provided and the values are compared to the corresponding [N,N,C,O] isomers. Data are provided for searching for these species in interstellar regions.