Microwave Spectrum and Structure of t-Butyl Nitrite

Microwave spectra of three isotopic species of t-butyl nitrite were assigned between 8.5 and 32 GHz, and the following rotational constants were obtained. _??_ The carrier of the observed spectrum is the conformer in which the C-0 and N-0 bonds are trans to each other. Cis form was not identified in the present search. A least-squares fit of the observed rotational constants yields C-0= 1.436±0.004Å, N-0=1.424±0.004Å, O=:1.170± 0.004Å, ∠ CON= 114.5±0.6°and ∠ONO = 111.6±0.6° as the structural parameters when C-H = 1.097A, C-C = 1.5 28A, ∠HCC = 1 09.5°, and ∠CCO= 107.0° are assumed. The structure was compared with those of other X-ONO molecules, and a systematic change in the XON or ONO bond angle with X-group is found. The XON bond angle increases in the following order: HONO