ELECTRONIC STATES AND SPECTRA OF BIO

The electronic spectrum of the BiO radical has been studied by Fourier transform emission spectroscopy, laser-induced fluorescence, and exci mer laser photolysis techniques. Six new electronic slates, A(1) (Omeg a = 3/2) (T-e = 11 528.8 cm(-1), w(e) = 530.4 cm(-1), w(e)x(e) = 2.42 cm(-1)), G (Omega = -3/2) (T-e = 20 273 cm(-1), w(e) = 499 cm(-1), w(e )s(e) = 2.6 cm(-1)), H (Omega = 1/2) (T-e = 20 469.76(6) cm(-1), w(e) = 471.63(15) cm(-1), w(e)x(e) = 2.153(35) cm(-1)), I(Omega = 1/2) (T-e = 21 882.50(2) cm(-1), w(e) = 506.50(11) cm(-1), w(e)x(e) = 3.263(34) cm(-1)), J(Omega = 3/2) (T-e = 25 598.95(42) cm(-1), w(e) = 489.95(16 ) cm(-1), w(e)x(e) = 2.309(45) cm(-1)), and K (Omega = 1/2) (T-e = 26 744.7(2) cm(-1), w(e) = 420.6(4) cm(-1), w(e)x(e) = 5.25(5) cm(-1)), a nd 14 new electronic transitions (A(1) <-- X-1, G --> X-2, H <-> X-2, H --> A(2)(A), I <-> X-1, I --> A(2), J <-> X-1, J <-> X-2, K <-> X-1, K <-> X-2, K --> A(2), B <-> X-2, B --> A(2), C <-> X-2) have been de tected. Time-resolved measurements of the fluorescence decays have yie lded the radiative Lifetimes of the upsilon = 0 levels of most stales up to <30 500 cm(-1) energy (tau(X2) = 480 +/- 100 mu s, tau(A2) = 9.3 +/- 1.5 mu s, tau(H) = 15 +/- 3 mu s, tau(I )= 16 +/- 3 mu s, tau(J) = 4.9 +/- 0.9 mu s, tau(K) = 2.6 +/- 0.3 mu s, tau(B) = 0.55 +/- 0.08 mu s, tau(C) = 0.84 +/- 0.15 mu s) and rate constants for quenching of the slates by some rare gas atoms and simple molecules. The new elect ronic states A(1), G, H, I, J, and K and the previously known levels X -1, X-2, A(2)(A), B, C, and D are assigned to spin-orbit slates arisin gs from low-energy valence configurations of BiO with the help of deta iled theoretical data calculated by Alekseyev et al. (J. Chem. Phys. 1 00, 8956-8968 (1994)). (C) 1998 Academic Press.