THE A(3)SIGMA-]X(1)SIGMA+ (X0+) TRANSITIONS OF BIP, BIAS, AND BISB( (A(1)1))

Chemiluminescence of the a3SIGMA+ (a1(1)) --> X1SIGMA+ (X0+) transitio ns of BiP, BiAs, and BiSb has been observed in the near-infrared spect ral region between 6000 and 10 000 cm-1 from the reactions of microwav e-discharged phosphorus, arsenic, and antimony vapor with bismuth vapo r in a fast-flow system. The spectra consisting of short sequences of red-degraded bands were measured at a resolution of 0.5 cm-1 with a Fo urier-transform spectrometer. Vibrational analyses of the systems have yielded the following molecular constants of the X0+ and a1 1 states of BiP, BiAs, and Bi Sb-121 (in cm-1): [GRAPHICS] Here the numbers in parentheses give the standard deviations of the parameters in units of the last digit. Weak bands of a second transition to the ground state of BiP were observed in the region 11 000-15 000 cm-1. The upper stat e with constants T(e) = 15093.1 (2) cm-1, omega(e) = 334.8 (2) cm-1, a nd omega(e)x(e) = 2.79(5) cm-1 is tentatively assigned to the OMEGA = 1 component of the lowest 3DELTA state of BiP. (C) 1994 Academic Press , Inc.