GC-MS exploration of photochemically generated species of Os, W and Ru from reductive and oxidative media

Abstract

The volatile synthetic products of photochemical vapor generation (PVG) of Os(IV) and W(VI) have been confirmed by GC-MS. Osmium tetroxide has been identified as the species generated from an oxidizing medium of dilute nitric acid, and tungsten hexacarbonyl is produced during PVG from a reducing medium of formic acid. Attempts to ascertain the PVG products of Os and Ru generated in high yield from reducing media (i.e., acetic and formic acids, respectively in the presence of metal sensitizers) were unsuccessful, possibly due to their instability or reactivity with the GC support, and thus remain to be identified using more direct approaches such as Direct Analysis in Real Time (DART)-MS. The mass spectra for OsO₄ and W(CO)₆, reported here for the first time, serve to aid the further development/refinement of mechanistic models for PVG.