THE IDENTIFICATION OF THE CLASSICAL DONOR-ACCEPTOR COMPLEX H3N-BF3 IN THE GAS-PHASE

The J = 1 <-- 0 rotational transitions of the four isotopomers (H3NBF3)-N-14-B-11, (H3NBF3)-N-14-B-10, (H3NBF3)-N-15-B-11, and (H3NBF3)-N-15-B-10 of the archetypal donor-acceptor complex formed between ammonia and boron trifluoride have been detected with a pulsed-nozzle, Fourier-transform microwave spectrometer; by using a fast-mixing nozzle, H3NBF3 has been isolated in collisionless expansion before condensation can occur, thereby allowing the first detection of this elusive species in the gas phase.