Structure, spectroscopy and dynamics of halogen molecules interacting with water

Abstract Immediately on the discovery of the halogen molecules, their chemistry was closely linked with that of water. For some time, it was thought that water was a constituent of chlorine. The brightly coloured halogens have played an important role in spectroscopy almost from the beginning of its use as a quantitative tool for understanding molecular structure. Already in the 19th century, the remarkable colour change upon dissolving iodine in aqueous solution was noted and studied. However, a complete, microscopic explanation for this phenomenon is yet to be achieved. We review this field and propose that the time is right to achieve this fundamental goal of chemical physics for the halogen–water system. In addition, we review recent work on the UV-vis, Raman and ultrafast dynamics studies of halogen molecules in clathrate hydrate cages, spectroscopy of water–halogen dimer molecules and theory of small water–halogen clusters. Based on recent findings, we propose a variety of 'next steps' for the complete understanding of this fascinating model system. Keywords: halogen bondinghalogen hydratebromine hydrateaqueous solutionUV-vis spectroscopyRaman spectroscopywater–halogen dimers ab initio theorysimulated spectra Acknowledgements We are very grateful to our colleagues: Everly Fleischer, V. Ara Apkarian, Ilya Goldshleger, Jordan Pio, Molly Taylor, Edward Branigan, Megan Johnson, Joanne Abbonbondola, Melissa Prado, Kenneth Jordan, Daniel Schofield, Ramón Hernández-Lamoneda, Oscar I. Arillo, Nadine Halberstadt and Tahra Ayed for many valuable inputs to the work discussed here. The Irvine work was supported by the United States National Science Foundation grant No. CHE-0404743. M.I. Bernal-Uruchurtu acknowledges the financial support of UC-MEXUS/CONACYT for her sabbatical year fellowship. Notes §On leave from Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, México; mabel@uaem.mx. Additional informationNotes on contributorsMargarita I. Bernal-UruchurtuFootnote§ §On leave from Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, México; mabel@uaem.mx.