UV laser desorption/ionisation mass spectrometry of the triruthenium clusters Ru-3(CO)(12-n)(PPh3)(n) (n=1, 2 and 3)

The negative ion ultraviolet laser desorption mass spectra of Ru-3(CO)(12) and its triphenylphosphine derivatives Ru-3(CO)(12-n)(PPh3)(n) (n = 1-3) ha ve been recorded using laser desorption/ionisation time-of-flight mass spec trometry (LDI-TOF-MS). The spectra contain peaks in the parent region toget her with peaks at higher masses due to extensive gas phase reactions. Subst itution of one to three carbonyls by the bulky triphenylphosphine ligand ha s a number of interesting effects on the spectra, most notably, increasing the degree of coordinative unsaturation of the gas phase clusters in the mo lecular ion region and increasing the intensity of the subsequent high mass reaction products. (C) 1999 Elsevier Science S.A. All rights reserved.