MOLECULAR-STRUCTURE OF N-CHLOROAZETIDINE STUDIED BY GAS ELECTRON-DIFFRACTION COMBINED WITH MICROWAVE SPECTROSCOPY

The geometric structure of N-chloroazetidine has been determined by gas electron diffraction (GED) and microwave (MW) spectroscopy. Rotational transitions of the vibrational ground state and excited states of the nu(16) (ring puckering) mode were measured by MW spectroscopy. In order to calculate mean amplitudes and shrinkage corrections, a normal coordinate analysis has been performed on the vibrational spectra recorded in the vapour and liquid phases. All the observed MW transitions and vibrational spectra were assigned to a single conformer. The data analysis of GED also shows that only the equatorial conformer exists at room temperature. The structural parameters (r(z) values) determined by a joint analysis of GED and MW data are r(N-C) = 1.485(3) Angstrom, r(C-C) = 1.551(3) Angstrom, r(N-Cl) = 1.741(2) Angstrom, r(C-H) = 1.0984 Angstrom, angle CNC = 90.4(4)degrees, angle CNCl = 115.0(2)degrees and phi = 32.4(17)degrees, where phi is the dihedral angle of the ring.