The Rotational Spectrum of TiO 2

Abstract

The rotational spectrum of titanium dioxide (TiO2) has been detected by laser-ablation molecular beam Fourier transform microwave spectroscopy. Thirteen b-type rotational transitions up to J = 9 and K a = 4 were measured for the most abundant isotopic species 48TiO2 in the frequency range 7-42 GHz with accuracies of 1-10 kHz, allowing for the precise determination of rotational and centrifugal distortion parameters. In addition, eight and six rotational transitions of the rare isotopic species 46TiO2 and 50TiO 2, respectively, have been recorded in the same frequency range. From the derived spectroscopic parameters, rest frequencies of TiO2 can now be calculated to better than 1 km s-1 in equivalent radial velocity up to fairly high J and Ka at millimeter wavelengths, enabling radioastronomical searches for this stable, highly polar transition metal dioxide in space. Preliminary results of two searches for TiO2 in space are presented. ? 2008. The American Astronomical Society. All rights reserved.