A predicted new type of directional noncovalent interaction

TLDR

Weak, directional noncovalent interactions are likely between Group V atoms with positive surface regions and nucleophiles, similar to those known for Groups VI and VII. The positive regions arise from σ‑hole effects, as demonstrated by natural bond orbital analyses. Electrostatic potential calculations show positive regions on Group V atoms, and MP2/6‑311++G(3df,2p) calculations confirm stable complexes with HCN. © 2007 Wiley Periodicals, Inc.; Int J Quantum Chem, 2007.

Abstract

Abstract The electrostatic potentials computed on the surfaces of a series of molecules R 3 X, where X is a Group V atom, show that some of these atoms have regions of positive potential on their outer surfaces, approximately on the extensions of the RX bonds. This suggests the likelihood of weak, directional noncovalent interactions between such atoms and nucleophiles, paralleling what has already been established for Groups VI and VII. The origins and relative strengths of the positive regions are explained in terms of the σ‐hole concept, supported by natural bond orbital analyses. MP2/6‐311++G(3df,2p) calculations confirm the formation of stable complexes between five such Group V molecules and the model nucleophile HCN. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007