Spectroscopic signatures as a probe of structure and dynamics in condensed-phase systems : studies of iodine and gold ranging from isolated molecules to nanoclusters

Abstract

This thesis focuses on spectroscopic studies of several different iodine- and gold-containing molecules, complexes and nanoscopic clusters. The systems have been studied in the condensed phase with a wide range of experimental and theoretical techniques. New spectroscopic signatures have been established for molecular h in solid crystalline Xe and for isolated I2-Xe-complex in solid Kr by using spectroscopic techniques. The vibrational signatures of several neutral (I2)n aggregate complexes in solid Kr have been identified using Resonance Raman spectroscopy. Electronic and vibrational absorption signatures of thiolate-protected gold nanocluster Au102(p-MBA)44 have been characterized experimentally from UV-region to far-IR region in solid and liquid phases. Implications of the spectroscopic findings for the dynamical and structural properties of the studied systems have been argued based on density functional calculations and molecular dynamics simulations. The new experimental results confirm the predicted electronic state structure for the Au102(p-MBA)44, and identify the elementary steps of h aggregation toward the crystalline phase. The results establish a novel electronic transition for the weak van der Waals complex I2-Xe in vacuum-UV absorption and suggest a plausible explanation for the origin. The results also reveal a novel spectroscopic finding of sharp vibronic B↔X structures for condensed-phase I2. The results open several interesting possibilities for additional studies of these systems.