One of the newest members of the noncovalent interactions’family is the pnicogen bonding. 1-2 In this work, the nature of bonding interactions between P and N atoms (P…N) in some of the phosphinidenes compounds have been studied via the energy decomposition analysis (EDA) based on the ETS-NOCV. The focus of the EDA is the instantaneous interaction energy (〖∆E〗_int) which is the energy difference between the molecule and the fragments with the frozen geometry of the complex. In this work the geometries of all compounds were fully optimized at the B3LYP/6-311++G** level of theory using the Gaussian 09 package3 .Also, the energy decomposition analysis (EDA) of P…N was performed using the program package ADF 2009.01 at BP86/TZ2P//B3LYP/6-311++G** level of theory with C1 symmetry.
