SPECTROSCOPY OF PENDULAR STATES - THE USE OF MOLECULAR-COMPLEXES IN ACHIEVING ORIENTATION

Infrared-laser-molecular-beam spectroscopy has been used to observe strongly bound pendular states of the linear hydrogen cyanide trimer. The spectrum undergoes a dramatic evolution from that of a free rotor al zero electric field, with its characteristic P and R branch structure, to that indicative of a pendulum bound by a large electric field (corresponding to omega = mu-E/B = 365). The result is an unprecedented degree of orientation for a linear molecule. The generality of using weakly bound complexes to orient even nonpolar molecules is discussed.