Atoms-in-molecules analysis of the effect of intermolecular interactions on dielectric properties in hydrogen-bonded material 5-bromo-9-hydroxyphenalenone

• Published in: International journal of quantum chemistry Vol. 113; no. 3; pp. 386 - 392
• Main Authors: Otaki, Hiroki, Ando, Koji
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 05.02.2013; Wiley Subscription Services, Inc
• Subjects: atoms in molecules; Chemistry; hydrogen bond; molecular crystal; organic dielectrics; phase transition; Physical chemistry; Quantum physics
• ISSN: 0020-7608; 1097-461X
• DOI: 10.1002/qua.24058

Intermolecular interactions in molecular crystal of 5‐bromo‐9‐hydroxyphenalenone are analyzed by means of Bader's theory of atoms in molecules. A set of criteria to ascertain the presence of a hydrogen bond is applied to two candidates of intermolecular contacts suggested by our previous work [Otaki and Ando, Phys. Chem. Chem. Phys. 2011, 13, 10719]. It is shown that they almost satisfy the criteria to confirm the existence of intermolecular CH···O hydrogen bond. In addition to the hydrogen bonding, other types of interactions, such as H···H and H···Br, are found in one of the candidates. The discussions are extended to explain how the molecular dipole moment is induced by surrounding molecules. It is also found that the bias in the atomic charges due to the electrophilicity of the oxygen atom is strongly correlated with the induced dipole moment. © 2012 Wiley Periodicals, Inc. Properties of crystals cannot be obtained by simple summation of those of an isolated molecule. Intermolecular interactions are investigated in molecular crystals by means of Bader's atoms‐in‐molecules analysis. The existence of an intermolecular CH…O hydrogen bond, which induces the molecular electric dipole moment in a way to be a determining factor of the dielectric phase transition temperature, is thus confirmed. The correlation with the electrophilicities of carbonyl and enolic oxygens is also discussed.