Laser ablation of ring-strained precursor molecules: selective product fragment generation

Molecular beam methods (photoionization, time-of-flight mass spectrometry) have been used to study the neutral products following 355 nm pulsed laser ablation of three ring-strained organic precursors that were deposited on 0.25 in. diameter rods. Consistent with earlier observations on two strained organometallic precursors, the predominant product fragments observed were the ones resulting from breaking the ring-strained bonds. In contrast, similar laser ablation of non-strained precursors resulted in substantial non-specific bond breaking. It appears that laser ablation of appropriate strained precursors may provide a general method for producing pre-selected fragments for further molecular beam study. It is also possible by this approach to develop schemes to collect significant amounts of the stable fragment products.