Microwave Spectrum of Methyl Germane

Abstract

The J=0→1 and 1→2 transitions of 28 isotopic species of CH₃GeH₃ have been measured. From the rotational constants obtained, the following structural parameters have been calculated: r_CH=1.083±0.005 A°, r_GeH=1.529±0.005 A°, r_CGe=1.9453±0.0005 A°, ≰HCH=108°25′±30′, ≰HGeH=109°15′±30′. The K=1 transitions of the asymmetrically deuterated species are split by internal rotation about the C–Ge bond. Withthe assumption of a threefold sinusoidal potential, an internal barrier of 1239±25 cal/mole has been determined from these splittings. Analysis of the Stark effect of several species gives a dipole moment of 0.635±0.006 D. From observed hyperfine structure the nuclear quadrupole coupling constant of Ge⁷³ has been calculated to be +3 Mc.