Characterization of intermolecular interactions in crystalline aspirin: A computational NQR study

A computational study at the level of density functional theory was carried out to characterize the 17O and 2H nuclear quadrupole resonance (NQR) spectroscopy parameters in crystalline aspirin. To include O?H...O and C?H...O hydrogen bonding effects in the calculations, the most probable interacting molecules with the target molecule in the crystalline phase were considered through a pentamer cluster. The NQR calculations were performed with BLYP, B3LYP, and M06 functionals employing 6-311++G** and Jensen's polarization-consistent pcJ-1 basis sets. Linear correlations are observed between the calculated 17O and 2H NQR parameters and the hydrogen bond strengths, suggesting the possibility of estimating hydrogen bonding information from calculated NQR data. Different contributions of various nuclei to hydrogen bonding interactions and observed trends of calculated NQR parameters are well justified by atoms in molecules analyses at the BCPs of these interactions. (C) 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012