Infrared laser spectrum of the fundamental band of the boron monoxide freeradical

The infrared diode laser absorption spectrum of the fundamental band of the boron monoxide (BO) radical in its ground (2)Sigma (+) state has been obse rved. The source of the radical was the reaction of BCl3 with (OP)-P-3 in t he absence of molecular oxygen. 15 lines of (BO)-B-11 and three lines of (B O)-B-10 have been measured. The (BO)-B-10 lines show a small, partially res olved, doublet structure of about 0.01 cm(-1) which is not present in the ( BO)-B-11 species. This is attributed to the complex hyperfine pattern expec ted for the B-10 (I = 3) nucleus. The band origins are 1861.92465(48) and 1 915.30554(16) cm(-1), respectively. Combining the diode laser value of B-t = 1.756829(11) cm(-1) with the microwave determination of B-o leads to a va lue of r(c) = 1.204068(7) Angstrom. for (BO)-B-11. (C) 2001 Elsevier Scienc e B.V. All rights reserved.