Fourier Transform Infrared Emission Spectroscopy of theb1Π–a1Σ+System of BN

✍ Scribed by R.S. Ram; P.F. Bernath

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 372 KB
• Volume: 180
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1996.0265

✦ Synopsis

The emission spectrum of BN has been investigated in the 1800-9000 cm 01 region using a Fourier transform spectrometer. BN was formed in a microwave discharge of He with a trace of BCl 3 and N 2 . The bands observed in the 3000-7800 cm 01 interval have been assigned as the b 1 P-a 1 S / transition, with the 0-0 band at 3513.99040(43) cm 01 . This transition is analogous to the A 1 P u -X 1 S / g (Phillips) system of the isoelectronic C 2 molecule. The rotational analysis of the 0-0, 1-1, 1-0, 2-1, 3-2, 2-0, 3-1, 4-2, and 4-1 bands has been obtained and the molecular constants for the b 1 P and a 1 S / states have been determined. A local perturbation has been observed in the £ Å 1 vibrational level of the b 1 P state near J Å 18 caused by the interaction with the £ Å 3 vibrational level of the a 1 S / state. The principal equilibrium constants for the a 1 S / state are: v e Å 1705.4032(11) cm 01 , v e x e Å 10.55338(52) cm 01 , B e Å 1.683771(10), a e Å 0.013857(16) cm 01 , and r e Å 1.2745081(37) A ˚. Although the b 1 P-a 1 S / transition has recently been seen in emission from boron nitride trapped in solid neon matrices [J. Chem. Phys. 104, 3143-3146 (1996)], our work represents the first observation of this transition of BN in the gas phase.