5314027797

POSTER SESSION. H9

ANALYSIS OF THE SPECTRA OF SILANE IN THE 2930 - 3300rm-^ł RANGĘ

M. TERKI-HASS A INE°, Ch. CLAVEAU^fc, A. YALENTIN⁶. and G. PIERRE". ^a Laboratoire de Physiąue de PUnwersitó de Bourgogne UPRES-A 5027 Thćońe des Systemes Molóculaires et des Phćnomenes non Linćaircs 9, Avenue Alain Savary, F-21011 Dijon-Cedei France ⁶Laboratoire de Physiąue Mole.culaire et Applications CNRS, Unwersite Pierre et Marie Curie, Tour 1.1, 4 Place Jussieu F-75005 Paris, France.

Three Fourier Transform Infrared Spectra of SiH j havc been recorrled bctween 2930 and 3300cm"¹ with the resolution of 1.8 x 10“³ cm"¹ and the fol Iow i ng cxperimcntal conditions

•

T = 209 K; p = 0.2torr\ t = 12m T = 297K\ p — 0.2/orr; t = 20m T = 297K; p = 0.8<orr; l = 20m

The two spectra at the Iow pressure (p = 0.2torr) are used to an&lyse the tctrad build with one quantuin of stretching modę (i/\ ot 1/3) and one quantum of bending modę (1s? ot iv₄) : u\ +    v\ + iaj(F'2). u2 + 1^4(Fi + F2) and i/j + Uą[A\ + E + F\ + Ą).

We use with vibrational extrapolation inethod, the rcsults of fundamental bending dyad (i^/ł/4)¹ and the stretching dyad (t/|/i^)². The comparison of the lines strength between the 297K and the 209K spectra gives some important infonnations on the Grotind State of the transition and help to their assigment.

The total vibrational degeneracy of this tetrad is cqual to 19. The hamiltonian is expended through tlie 6^f/l order for the ground and the bending States, 5^ł/* order for the stretching States and \\^tłx order for the tctrad States. About 800 data are used in the analysis and the standard deviation obtained is 3 x I0“³cm“^ł.

Using the rcsults of the analysis it is possible to assign many lines of the hot bands tetrad minus bending dyad. The analysis of these bands will be madę soon.

1

   G. Pierre et al., Can. J. Phys64, 341-350 (1986)

2

   B. Lavorel et al., J. Mol. Spectrosc., 143. 35-49 (1990)