Analysis of the microwave spectrum of the bis-trifluoromethyl nitroxide

The microwave spectrum of the stable free radical bis-trifluoromethyl nitroxide was analyzed in the 20 to 26.5 GHz region. 39 transitions have been assigned. The rigid rotor rotational constants determined by calculation of the hypothetical unsplit rotational transitions are A= 2256.94 MHz, B= 1056.08 MHz, and C=971.51 MHz. A program to calculate the fine and hyperfine splitting patterns was written which reproduced the experimentally observed splittings. The spin-rotation coupling constants are Eaa = -3597.7 MHz, Ebb= -1121.4 MHz, and Eee = 29.8 MHz. The magnitude of Eee indicates that the unpaired electron is in an orbital extending perpendicularly to the molecular plane. The determined magnetic hyperfme coupling constants are Taa= -183.74 MHz, Tbb= -177.77 MHz, Tee= 361.51 MHz, and aF= 22.8 MHz. The spin density on the fluorine atom is 11.9% which is estimated from the value of Tee· The value of the Fermi coupling constant aF indicates that the unpaired electron occupies an unhybridized p orbital. An insufficient number of unsplit rotational transitions were assigned to allow a centrifugal distortion analysis to be performed. Since isotopic substitution was not feasible an r0 structure was determined by doing a least squares fit of the three moments of inertia. The following parameters were not allowed to vary during the least squares fit: reF= 1.32A,rcN= 1.441A, F - C - F = 109.8° . The calculated structure gave a N-0 bond length of 1.212A ,a C-N-0 angle of 116.9° a C-N-C ·angle of 126.2° , and an angle which measures the deviation of the 0 atom from the CNC plane of 0° .

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1986

Author dc:creator

• White, Richard Michael

Chair dc:contributor.committeechair

• Graybeal, Jack D.

Committee members dc:contributor.committeemember

• Harris, Paul J.
• Sanzone, George
• Viers, Jimmy W.
• Ward, Thomas C.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/77789

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/77789