ANALYSIS OF THE INFRARED FOURIER-TRANSFORM SPECTRUM OF THE NU-2 NU-4 DYAD OF SNH4-(SN-116)

The FTIR spectrum of monoisotopic 116SnH4 has been recorded with the Bruker 120 HR interferometer at Giessen, West Germany, in the ν2 ν4 range extending from 600 to 850 cm-1. The resolution (FWHM) was 2.1 × 10-3 cm-1. The Dyad ν2 ν4 (0100, 0001) was analyzed using a sixth-order Hamiltonian. The analysis of infrared transitions enabled us to determine 10 ground state parameters, 9 ν2 parameters, 17 ν4 parameters, and 18 interaction parameters. Of 3800 calculated transitions assigned to observed lines, 1183 unblended lines have been selected for the data refinement. For J ≤ 19, the value of the standard deviation is of the order of magnitude of the estimated experimental accuracy (30 × 10-6 cm-1). Nearly all the calculated lines of the Dyad have been observed; some additional lines in the spectrum belong to hot bands. Data related to the letter may be used, in connection with the parameters of the Dyad, to make predictions for the Triad energy levels (0200, 0101, 0002). © 1990.