The high-resolution infrared spectrum of triacetylene

Abstract

The high resolution Fourier transform infrared spectra of the ν 5, ν 6, ν 11, and ν 8 + ν 11 bands of triacetylene have been recorded. More than 1300 transitions have been assigned using an interactive Loomis-Wood program to facilitate the rovibrational analyses of these bands and their associated hot bands. The ground and excited state rotational and centrifugal distortion constants together with band origins and vibration-rotation parameters are presented. The ground state rotational constant, B 0, of 0.04417223(15) cm −1 is compared with B e values obtained from ab initio calculations and with a B value calculated from an expected geometry of triacetylene based on the known r s geometry of HC 5N.