This project seeks to measure the shape and size of metal clusters that can be introduced to the gas via electrospray ionization. For example, it was discovered more than 10 years ago that silver hydride cationic clusters can be generated from silver–amino species. Advances in ionization techniques have also led to the ability to generate bare metal cluster species. Thus, various electrospray solutions (e.g. concentrations, solvent, additives) and conditions (harsh versus soft, nanoESI versus ESI) will be used to tune the gas phase formation of clusters of interest. Subsequently, the collisional cross-sections will be measured using travelling wave ion-mobility, a state of the art technique for measuring shapes of individual isolated molecular species. These results will then be compared to those obtained via electronic structure calculations and theoretical models of CCS.
As new experimental apparatus has been introduced in 2016, future directions for this project include the exciting possibility of step-wise ion-molecule reactions at ambient conditions, such as, e.g. for Fe-S clusters (implicated in ammonia catalysis and nitrogenase enzymes), H2 followed by N2 reactions in two independent reaction steps.
Khairallah, O'Hair, Angew. Chem. Int. Ed. 2005, 44, 728 –731.
Wleklinski, Sarkar, Hollerbach, Pradeep, Cooks, Phys. Chem. Chem. Phys., 2015, 17, 28, 18364.
Rijs, Weiske, Schlangen, Schwarz, Anal. Chem. 2015, 87, 9769–9776.