Journal of Chromatography & Separation Techniques
Open Access

Mass spectrometry in cluster science: Formation of cluster ions, magic number clusters and their fragmentation studies by tandem mass spectrometry

International Summit on Current Trends in Mass Spectrometry

July 13-15, 2015 New Orleans, USA

Anil K Shukla1 and Bogdan Bogdanov2

Posters-Accepted Abstracts: J Chromatogr Sep Tech

Abstract :

Mass spectrometry in combination with an electrospray ion source provides an efficient and a powerful method for generating ionic clusters and studying their structure and characteristics. We have produced cationic and anionic clusters of lithium formate and studied their fragmentations by tandem mass spectrometry (collision-induced dissociation with N2). Singly as well as multiply charged clusters were formed in both positive and negative ion modes with the general formulae, (HCOOLi)n Li+, (HCOOLi)n Limm+, (HCOOLi)n HCOO- and (HCOOLi)n (HCOO)m mâ??. Several magic number cluster ions were observed in both the positive and negative ion modes although more predominant in the positive ion mode with (HCOOLi)3 Li+ being the most abundant and stable cluster ion. Quantum chemical calculations were performed for smaller cluster ions that showed the trimer ion has a closed ring structure similar to the phenalenylium structure with three closed rings connected to the central lithium ion. Further additions of monomer units result in similar symmetric structures for hexamer and nonamer cluster ions.