Substituent effects on geometry and bonding properties of asymmetric bifurcated pnicogen bonds: A theoretical study

We demonstrate for the first time the existence of bifurcated pnicogen bonds (BPBs) interactions formed between PX3 (X=F and Cl) and 1,10 phenanthroline derivatives. The nature of these BPBs interactions is studied by means of molecular electrostatic potential, quantum theory of atoms in molecules and natural bond orbital analysis. The interaction energies of these binary complexes vary in a relatively narrow range, approximately between -8.8 and -10.0 kcal/mol. There is an important charge-transfer interaction associated with each P center dot center dot center dot N interaction. A good linear correlation is found between the interaction energies and shifts in the N-14 nuclear quadrupole coupling constants. (C) 2016 Elsevier B.V. All rights reserved.