Synthesis and isolation of titanium metal cluster complexes and ligand-coated nanoparticles with a laser vaporization flowtube reactor

A new laser vaporization flow reactor (LVFR) is described consisting of a laser ablation cluster source combined with a fast flowtube reactor for the production and isolation of ligand-coated metal clusters. The source includes high repetition rate laser vaporization with a 100 Hz KrF (248 nm) excimer laser, while cluster growth and passivation with ligands takes place in a flowtube with ligand addition via a nebulizer spray. Samples are isolated in a low temperature trap and solutions containing the clusters are analyzed with laser desorption time-of-flight mass spectrometry. Initial experiments with this apparatus have trapped Ti-x(ethylenediamine)(y) complexes which apparently have linear metal units with octahedral ligand coordination. Other experiments have produced and isolated clusters of the form TixOy(THF)(z) that apparently have linear metal oxide cores and larger (TiO2)(x)(THF)(y) nanoparticle species. The isolation of these new cluster species suggest that the LVFR instrument has considerable potential for the production of new nanocluster materials.