مهدی اسرافیلی دیزجی

Ab initio calculations at the MP2/aug-cc-pVTZ level of theory are performed to investigate the effect of hydrogen-bonding cooperativity on the strength and bonding properties of σ-hole interaction in linear FCl•••(NCH)n=2-5, FHS•••(NCH)n=2-5, FH2P•••(NCH)n=2-5 and FH3Si•••(NCH)n=2-5 clusters. It is found that the cooperative effects in the hydrogen-bonding tend to strengthen the σ-hole interaction. However, these effects are almost saturated in the larger clusters (n > 5). For a given cluster, the amount of bond contraction in FCl•••(NCH)n is more important than other systems. A nice linear relationship is found between the σ-hole bond energies and absolute 15N chemical shieldings or spin-spin coupling constants across the σ-hole bond.