Reactivity of phosphorus mononitride and interstellar formation of molecules containing phospazo linkage: A computational study on the reaction between HSi (X 2 II) and PN (X 1 ∑ +)

Phosphorus mononitride (PN) shows some interesting chemistry due to its low dissociation energy (compared to N₂) and small dipole moment (zero dipole moment for N₂). In this work, a reaction between HSi (X2 II) and PN (X1∑+) has been studied using various computational methods. Analysis of the doublet surface of the HSi+PN reaction indicates that the reaction is exothermic in nature leading to the formation of various products. In view of the barrierless association of the reactants and exothermic nature for the product formation, it is suggested that species like HPNSi, cyclic-SiN(H)P (these two most stable isomers have phosphazo linkage) and HSiNP (third most stable isomer has phosphdiazo linkage) can possibly be detected in the interstellar medium. In view of the potential applications of phosphazo compounds in amide synthesis and pervasive nature of amide linkages in the nature, possible interstellar prebiotic applications can be advocated for these compounds.