Microwave Spectrum and Molecular Constants of Nitrosyl Bromide

The microwave spectrum of NOBr has been studied in the region 20 000 to 40 000 Mc/sec and an analysis made of the J = 2→3 transition. The following molecular constants were obtained. NOBr79NOBr81Rotational constants (Mc/sec)A83 34083 340B3747.243722.49C3586.003563.34Asymmetry parameterb−0.001012−0.000998Quadrupole coupling components (Mc/sec)χaa 388.3 325.5χbb−239.5−200.2χcc−148.8−125.3The structural parameters obtained from these are d(N–O) = 1.15 A, d(N–Br) = 2.14 A, d(O–Br) = 2.81 A, and ∠Br–N–O = 114°. The interatomic distances are compared with electron diffraction results, and a brief interpretation of the quadrupole coupling in terms of chemical bonds is given.