Infrared diode-laser spectroscopy of phosphoryl bromide (BrPO)

Many lines of the nu(1) P=O stretching fundamental of the transient molecul e BrPO have been detected between 1251 and 1266 cm(-1). The band resembles a parallel band of a near-prolate asymmetric top. Although it was not possi ble to obtain the A rotational constant exactly, both B and C were precisel y determined subject to an assumed value of A = 1.021 cm(-1). The rotationa l constants so determined are in satisfactory agreement with ab initio valu es calculated from a density functional structure RP-O = 1.4719 Angstrom, R P-Br = 2.2324 Angstrom, and angle(Br-P-O) = 110.48 degrees. The experimenta l (81)BrpO and (BrPO)-Br-79 band origins are 1257.8178 and 1257.8439 cm(-1) , respectively. The derived rotational constants are sufficiently accurate for reliable microwave predictions. (C) 1999 Academic Press.