Microwave Spectrum of Ethyl Iodide, I.

Abstract

Microwave spectrum of ethyl iodide molecule C ₂ H ₅ I was studied. The obtained rotational constants are: A =29106.2±0.5 Mc/sec, B =2979.2±0.1 Mc/sec and C =2797.1±0.1 Mc/sec, which lead to the structure as d _CI =2.139±0.005 Å and \({\angle}\text{CCI}{=}112\)°10'±20' with the assumption of d _CC =1.54 Å. The calculation of the second order quadrupole effects for slightly asymmetric molecule with a plane of symmetry gave the asymmetry parameter η=( q _{b b} - q _{c c} )/ q _{a a} of 0.205±0.005 and ξ= q _{a b} / q _{a a} of -0.57±0.05 as well as the coupling constant e q Q of -1771±10 Mc/sec along C–I bond. The components of the electric dipole moment were determined to be µ _a =1.75±0.05 D and µ _b =0.25±0.1 D. Centrifugal constants were obtained as D _K =0.36±0.05 Mc/sec, D _{J K} =-0.151±0.005 Mc/sec and D _J <0.05 Mc/sec.