| Abstrakt: |
SiP molecules have been produced in a molecular free jet apparatus by laser vaporizing a silicon rod in the presence of He doped with phosphine (PH[sub 3]) gas. Excitation spectra have been observed in the 21200–22350 cm[sup –1] range by monitoring laser induced fluorescence. Dispersed fluorescence spectra have been recorded out of the upper states of the excitation bands. The ground electronic state is X [sup 2]Π[sub i] with the spin–orbit splitting A=-186.774(11) cm[sup -1], the harmonic wavenumber ω[sub e]=615.7(6) cm[sup -1], and the equilibrium internuclear distance r[sub e]=2.0775(17) Å. Two excited electronic states, A [sup 2]Σ[sup +] and B [sup 2]Σ[sup +], are observed at T[sub 0]=427.4(5) and 21317.1(1) cm[sup -1], respectively. The harmonic wavenumbers, ω[sub e], and the equilibrium internuclear distances, r[sub e], are 680(2) cm[sup -1] and 1.9658(13) Å, respectively, for the A [sup 2]Σ[sup +] state and 455(1) cm[sup -1] and 2.1278(8) Å, respectively, for the B [sup 2]Σ[sup +] state. For the X [sup 2]Π[sub i], A [sup 2]Σ[sup +], and B [sup 2]Σ[sup +] electronic states, RKR potentials have been generated. Franck–Condon factors for the B–X, B–A, and A–X systems have been calculated. A [sup 2]Σ[sup +], v∼X [sup 2]Π[sub 1/2], v+1 perturbations have been observed. A deperturbation procedure has yielded the off-diagonal spin–orbit electronic matrix element equal to 51(8) cm[sup -1]. This work represents the first spectroscopic investigation of the SiP molecule. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
