HALOGEN-BONDED MATERIALS

Abstract

Halogen Bonding (XB) has generated huge excitement over the past decade in both the experimental and theoretical communities, due to its promise in applications such as drug design and functional material engineering. The non-covalent interaction, being very similar to hydrogen bonding (HB), has been advocated to be sufficiently well described by the electrostatic picture. Through a series of quantum chemical studies of several XB dimers involving aromatic and N-heteroaromatic acceptors, we demonstrated that charge transfer cannot be neglected when predicting their optimal binding sites. Subsequently, we verified our claim with a larger set of 40 XB dimers with the newly developed adiabatic absolutely localized molecular orbital energy decomposition analysis scheme. The second part of the thesis involves the study of the electronic effect of XB on the intersystem crossing (ISC) and phosphorescent rates of benzaldehyde and quinoline. From our results, it is clear that XB do not always bring about the enhancements of these rates as claimed in the literature. Furthermore, from the preliminary study involving quinoline, our data suggests that the changes in ISC and phosphorescent rates is site-specific.