Microwave Spectrum, Structure, and Dipole Moment of ``Cis''-N2F2

Abstract

The microwave spectra of the F¹⁴N¹⁴NF and F¹⁵N¹⁴NF isotopic forms of the ``active'' isomer of N₂F₂ are reported and from this the structure is derived as planar and cis with the following structural parameters: d(NN)=1.214±0.005 Å, d(NF)=1.384±0.01 Å, ∠FNN=114.5±0.5°. A dipole moment of 0.16±0.01 D has been evaluated from the rotational Stark effect. Transitions of the molecule in an excited vibrational state are reported. From relative intensity measurements of this state, a vibrational frequency of 300±35 cm^‐1 is estimated. A method is demonstrated enabling the ratio of nuclear spin statistical weights of two transitions to be determined from the growth rate of their intensities with increasing Stark modulation voltage.