ROTATIONAL SPECTRUM AND MOLECULAR-PROPERTIES OF THE DINITROGEN-CHLORINE MONOFLUORIDE COMPLEX

The ground-state rotational spectra of the three isotopemers N-14(2) . ..(ClF)-Cl-35, N-15(2) ...(ClF)-Cl-35 and N-15(2) ...(ClF)-Cl-37 of a complex formed by dinitrogen and chlorine monofluoride have been obser ved with a pulsed-nozzle, Fourier-transform microwave spectrometer. Th e spectroscopic constants B-0, D-J, chi(aa)(A) (A = N-14(i), N-14(o) o r Cl) and M(bb)(Cl) are reported. The complex is shown to have a linea r (or nearly linear) arrangement NoNi ... ClF of the nuclei in the equ ilibrium conformation with r(N-i ... Cl) = 2.920(2) Angstrom. The inte rmolecular stretching force constant, k(sigma) = 5.00(5) N m(-1), is i mplied by the centrifugal distortion constant D-J. Interpretation of t he nuclear quadrupole coupling constants chi(aa)(A) leads to the oscil lation angles theta(av) = cos(-1)[cos(2) theta](1/)2 = 17.8(5)degrees and phi(av) = cos(-1)[cos(2) theta](1/2) = 10(3)degrees for the N-2 an d ClF subunits, respectively. Additionally, the diffence chi(aa)(N-i)- chi(aa)(N-o) leads, on the basis of a simple model, to the conclusion that the polarisation of N-2 attending complex formation is equivalent to the transfer of a fraction delta approximate to 0.02 of an electro nic charge from N-o to N-i. A comparison of the properties of four rel ated complexes N-2 ... YF and OC ... YF, where Y = Cl or H, is present ed.