The chemistry of nanostructured materials is an important technological area of research where the properties of such materials are determined by interaction between the building blocks and their associated interfaces. One route for the synthesis of such materials or their associated composites is by gas phase condensation. In this method the substrate materials are evaporated in an inert atmosphere and then condensed to form micro-clusters. Consequently, an important criterion for the study of the laser induced gas phase ion chemistry of such materials is that it can provide a guide to the synthetic stability of selected micro-clusters as well as provide thermochemical results. Such science provides for a better understanding of the condensed phase/vapor equilibrium associated with these materials.

Our recent laser ablation mass spectrometry experiments have revealed that a large number of remarkable polynuclear clusters can be generated by laser ablation. In our experiments the term laser ablation is used to indicate laser-induced photodecomposition / ionisation of the selected material as distinct from laser desorption / ionisation of a species from a substrate. We have previously examined the anion metal chalcogenide clusters with the general composition [M_nE_m]^-, E = S, Se, Te. Besides their production, a trenchant result is that there is a continuous series of ions for each combination of M and E, and that the maps of n, m for each element pair are clearly dependent on M, and largely independent of the precursor solid. Furthermore, our experiments show that these clusters are formed in the laser plume by assembly of components generated by the laser pulse on the solid precursor, and that these clusters represent stable combinations of the elements which are expected to have high electron affinities (eg., ReO > 3.5 eV).

In this paper we present the results of a laser ablation FT-mass spectrometry study of tin sulfide. The methodology of our experiment involves:

1. The laser ablation of the tin sulfide to establish which ions can be generated and trapped in the FT-mass spectrometer.
2. The collision induced dissociation of photoablated ions (eg., (SnS)xSn+ and (SnS)xS-) with argon and helium to probe their geometrical structures.
3. Chemical bracketing to determine the electron and proton affinities of selected ions.
4. Collision assisted ion-molecule reactions of the clusters with selected organic (alcohols, thiols etc.) and inorganic (H₂O, CO₂ , NO₂ etc.) gas phase molecules to probe cluster reactivities and
5. Density functional computations on ionic clusters to determine their electronic and geometrical structures as a probe of their reactivities from predicted spin states.

In our experiments positive and negative charged clusters were trapped and their reactivities studied under conditions not unlike those employed in thin film manufacture.