MASS-SPECTRA OF NEGATIVELY CHARGED WATER AND AMMONIA CLUSTERS

Slow electrons are mixed into a heavily clustered supersonic expansion of water and ammonia. The resulting negatively charged cluster ions are mass analyzed. Mass spectra for (H//2O)//n** minus , (D//2O)//n** minus , and (NH//3)//n** minus are presented. The smallest cluster ions observed contain 11, 12, and 36 water, heavy water and ammonia molecules per clusters, respectively.