15min:

XIUJUAN ZHUANG AND TIMOTHY C. STEIMLE, Department of Chemistry and Biochemistry, Arizona State University, Tempe,AZ 85287; RAMYA NAGARAJANN AND JOHN P. MAIER, Department of Chemistry, University of Basel, Basel Switzerland.

Bulk TiO₂ is a widely used photo-activated catalytic material, yet poorly understood. Much of the motivation for studies of molecular TiO₂ is the observation that there is a smooth correlation of the molecular electronic states to the band gap of the bulk. The field-free energy levels of the ground state of the monomer have been fully characterized by microwave spectroscopy. Here we report on the visible spectrum in the region between 18200 cm^-1 to 18750 cm^-1 of a cold molecular beam sample of TiO₂ using laser induced fluorescence detection and mass-selected REMPI. Bands at 18240 cm^-1, 18411 cm^-1 and 18470 cm^-1 were recorded at a resolution of 40 MHz and rotationally analyzed. The dispersed fluorescence of 18411 cm^-1 and 18470 cm^-1 bands were analyzed to produce a set of vibrational parameters for the ground state. The optical Stark spectra of the 18411 cm^-1 and 18470 cm^-1 bands were recorded and analyzed to determine permanent electric dipole moments and compared with the results for the band at 18655 cm^-1