Rotational spectrum, internal dynamics, and molecular structure of methylphenylsilane

Juncheng Lei; Junhua Chen; Zhangyou Yang; Gang Feng; Zhining Xia; Qian Gou

doi:10.1063/1.5099701

Rotational spectrum, internal dynamics, and molecular structure of methylphenylsilane

J Chem Phys. 2019 Jun 21;150(23):234302. doi: 10.1063/1.5099701.

Authors

Juncheng Lei¹, Junhua Chen¹, Zhangyou Yang², Gang Feng¹, Zhining Xia¹, Qian Gou¹

Affiliations

¹ Department of Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331 Chongqing, China.
² Pharmaceutical Engineering Research Center, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China.

PMID: 31228918
DOI: 10.1063/1.5099701

Abstract

The rotational spectra of two isotopologues of methylphenylsilane were measured and assigned by using the supersonic-jet Fourier transform microwave spectroscopic technique in the 2.0-20.5 GHz range. The feature of rotational spectra of methylphenylsilane indicates that the doublets of rotational transitions in methylphenylsilane are contributable to the methyl internal rotation with a V₃ barrier of 559 (25) cm^-1. No splitting has been observed due to the methyl internal rotation in its carbon analog, ethylbenzene, which indicated that the barrier to such motion should be higher than 700 cm^-1. Silicon incorporation of the ethyl group in ethylbenzene leads to a much lower barrier to the methyl internal rotation.