Reconciling Electrostatic and n??* Orbital Contributions in Carbonyl Interactions.

ABSTRACT: Interactions between carbonyl groups are prevalent in protein structures. Earlier investigations identified dominant electrostatic dipolar interactions, while others implicated lone pair n??* orbital delocalisation. Here these observations are reconciled. A combined experimental and computational approach confirmed the dominance of electrostatic interactions in a new series of synthetic molecular balances, while also highlighting the distance-dependent observation of inductive polarisation manifested by n??* orbital delocalisation. Computational fiSAPT energy decomposition and natural bonding orbital analyses correlated with experimental data to reveal the contexts in which short-range inductive polarisation augment electrostatic dipolar interactions. Thus, we provide a framework for reconciling the context dependency of the dominance of electrostatic interactions and the occurrence of n??* orbital delocalisation in C=O???C=O interactions.

SUBMITTER: Muchowska KB 

PROVIDER: S-EPMC7496118 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature