H(3)Si(37)Cl Revisited with High Resolution: The Ground State and the v(2) = 1; v(3) = 1, 2, and 3; v(5) = 1; v(6) = 1 and 2; and v(3) = v(6) = 1 States.
The infrared spectrum in the range 400-1600 cm(-1) of isotopically pure H(3)Si(37)Cl has been recorded at high resolution (2.4-6.6 x 10(-3) cm(-1)) and analyzed. Fifteen bands have been studied, namely the four fundamentals nu(3) (543.968 cm(-1)), nu(6) (663.738 cm(-1)), nu(2) (947.982 cm(-1)), and nu(5) (950.657 cm(-1)), the overtone bands 2nu(3), 2nu(0)(6), and 2nu(-/+2)(6), the combination band nu(3) + nu(6), and seven hot bands. Improved ground state constant parameters have been obtained, including all four sextic distortion constants. As for the J-independent parameters A(0), D(0)(K), and H(0)(K), they were determined mainly through the "loop method" involving nu(6), 2nu(-/+2)(6), and 2nu(-/+2)(6)-nu(+/-1)(6) and checked through the strong interactions between nu(2) and nu(5), producing some "forbidden lines." The nu(2)/nu(5) dyad was fitted with success using two different reduced Hamiltonians. Concerning nu(3) and nu(6), in spite of their relatively large separation, a Coriolis interaction could be evidenced. In both nu(2)/nu(5) and nu(3)/nu(6) interacting systems the sign of the interaction was found positive. As for the overtones, 2nu(3) was treated as isolated and 2nu(0)(6) and 2nu(-/+2)(6) as linked together by an l(2, 2) interaction. The data on the v(3) = v(6) = 1 levels were obtained mainly from the two hot bands nu(3) + nu(6) - nu(3) and nu(3) + nu(6) - nu(6), and marginally from the weak band nu(3) + nu(6), and also fitted as for an isolated level. A weak x,y-Coriolis interaction with level crossing between K/(kl - 1) = 21 and 22, and a local l(1, -2) resonance at K = 13/kl = -15 between 2nu(3) and nu(5) were furthermore detected. Copyright 1999 Academic Press.
Bürger
H
Anorganische Chemie, FB9, Universität-Gesamthochschule, Wuppertal, D-42097, Germany
Bailleux
S
Graner
G
Bosc
S
Hennequin
Y