ROTATIONAL SPECTRUM OF THE NITROGEN TRIFLUORIDE-CHLORINE MONOFLUORIDECOMPLEX AND THE INDUCTIVE EFFECT OF GROUPS R = CH3, H, F ON R3N CLF INTERACTIONS/

Rotational constants B-0, centrifugal distortion constants D-J and D-J K, and nuclear quadrupole coupling constants chi(aa)(N-14) and chi(aa) (Cl) were determined by pulsed-nozzle, Fourier transform microwave spe ctroscopy for the isotopomers F-3(14) N ...(ClF)-Cl-35 and (F3N)-N-14 ..(ClF)-Cl-37 of a complex formed by nitrogen trifluoride anhchlorine monofluoride. The distance r(N ... Cl) and the intermolecular stretchi ng force constant k(sigma) for this symmetric-top species are compared with those of several axially symmetric complexes B ... ClF in which a nitrogen atom of the base B interacts with ClF. In particular, it is shown that r(N ... Cl) decreases along the series R3N ... ClF, where R = F, H or CH3, while k(sigma) increases dramatically. (C) 1998 Elsev ier Science B.V. All rights reserved.