Physical Nature of Substituent Effects in XH/π Interactions

XH/π interactions (e.g.: CH/π, OH/π, etc.) are ubiquitous in chemical and biochemical contexts. Although there have been many studies of substituent effects in XH/π interactions, there have been only limited systematic studies covering a broad range of substituents. We provide a comprehensive and systematic study aimed at unraveling the nature of aryl substituent effects on model BH/π, CH/π, NH/π, OH/π, and F/π interactions (e.g.: BH3···C6H5Y, CH4···C6H5Y, etc.) based on estimated CCSD(T)/aug-cc-pVTZ interaction energies as well as symmetry-adapted perturbation theory (SAPT) results. We show that the impact of substituents on XH/π interactions depends strongly on the identity of the XH group, and the strength of these effects increases with increasing polarization of the XH bond. Overall, the results are in accord with previous work and follow expected trends from basic physical principles. That is, electrostatic effects dominate the substituent effects for the polar XH/π interactions (NH/π, OH/π, and FH/π), while dispersion effects are more important for the nonpolar BH/π and CH/π interactions. The electrostatic component of these interactions is shown to correlate well with Hammett constants (σm), while accounting for the dispersion component requires consideration of molar refractivities (MR) and interaction distances concurrently. The correlation of the dispersion component of these interactions with MR values alone is rather weak.

Related Products

Cat.No. Product Name Information
S1077 SB202190 (FHPI) SB202190 (FHPI) is a potent p38 MAPK inhibitor targeting p38α/β with IC50 of 50 nM/100 nM in cell-free assays, sometimes used instead of SB 203580 to investigate potential roles for SAPK2a/p38 in vivo. SB202190 inhibits endothelial cell apoptosis via induction of autophagy and heme oxygenase-1. SB202190 significantly suppresses Erastin‐dependent ferroptosis.

Related Targets

Autophagy p38 MAPK Ferroptosis Apoptosis related