NEUTRALIZATION-REIONIZATION MASS-SPECTROMETRY EXPERIMENTS CONFIRM THEPREDICTED EXISTENCE OF CYCLIC SI2O AND SI2N CLUSTER MOLECULES

Collision experiments are reported for Si2X+ (X = 0, N) generated by d issociative ionization of (SiH3)20 and (SiH3)3N in the gas phase. It i s argued that both the ionic and the neutral Si2X clusters have a tria ngular geometry as predicted for Si2O by a recent, thorough ab initio MO study (Boldyrev, A. I.; Simons, J. J. Phys. Chem. 1993, 97, 5875). While the linear connectivity SiSiX cannot rigorously be ruled out, th e symmetrical linear structure SiXSi is certainly not generated in the present experiment.