Fourier transform spectroscopy of chemiluminescence from the A′1Π-X1Σ+ system of SrO

The A'(1) II-X(1)Sigma(+) near infrared system of strontium oxide (SrO) was observed at high spectral resolution by measuring the chemiluminescence from a Broida flow reactor using a Fourier transform spectrometer. In total, 32 bands from (SrO)-Sr-88, (SrO)-Sr-87, (SrO)-Sr-86 were measured within the 4000-10000cm(-1) spectral region at a resolution of 0.03cm(-1). Vibrational levels of the upper state were observed up to v(A') = 4, and more than 5600 rotational lines were assigned. Incorporating previously published high resolution data for the A(1)Sigma(+)-X(1)Sigma(+) system, a global fit to both data sets yields improved Dunham constants for the ground state and for the lower vibrational levels (v(A') = 0, 1, and 2) of the A'(1) II state. Because perturbations arising from interactions with the b(3)Sigma(+) and A(1)Sigma(+) states affect the higher vibrational levels of the A'(II)-I-1 state more strongly, levels v(A') = 3 and 4 were represented by effective band constants in the fits. RKR potentials for the X-1 Sigma(+) , A'(II)-I-1, and b(3)Sigma(+), states have been generated utilizing all the available data, Franck-Condon factors have been calculated for the A'(II)-I-1-X(1)Sigma(+) system, and A'(1) H similar to b(3)Sigma(+) and A'(1) H similar to A(1)Sigma(+) perturbations are discussed. (C) 2003 Elsevier Science (USA). All rights reserved.