The microwave spectrum of tert-butyl isocyanate

authored by

J. U. Grabow, N. Heineking, W. Stahl

Abstract

The rotational spectrum of tert-butyl isocyanate, (CH₃)₃C-NCO, has been assigned using pulsed molecular beam microwave Fourier transform spectroscopy. The rotational constants are A = 4572.6 MHz (assumed), B = 1632.948 (15) MHz, C = 1630.493 (14) MHz; the barrier to internal rotation of the tert-butyl group (assumed to constitute a symmetric internal rotor, the NCO group forming the frame) is V₃ = 41.510 (15) cm^-1, the moment of inertia of the internal top is I_α = 111.388 (4) amu · A ̊², and the angle between the internal rotor axis and the a-principal inertia axis is θ = 24.169 (3)°. The nitrogen nuclear quadrupole coupling constants are χ_aa = +2.6376 (4) MHz, χ_bb = -1.4935 (7) MHz, χ_cc = -1.1441 (7) MHz, χ_ac = +0.1731 (15) MHz (the molecule has an ac-plane of symmetry). The principal elements of the coupling tensor are χ_zz = +2.6455 MHz, χ_xx = -1.4935 MHz, χ_yy = -1.1520 MHz; the angle between both axis systems is 〈(az) = +2.615° (with the x-axis perpendicular to the symmetry plane).

Organisation(s)

Institute of Physical Chemistry and Electrochemistry

External Organisation(s)

Kiel University

Type

Article

Journal

Journal of molecular spectroscopy

Volume

154

Pages

129-136

No. of pages

8

ISSN

0022-2852

Publication date

07.1992

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics, Spectroscopy, Physical and Theoretical Chemistry

Electronic version(s)

https://doi.org/10.1016/0022-2852(92)90034-L (Access: Unknown)