Formation and Characterisation of the Silver Hydride Nanocluster Cation [Ag3H2((Ph2P)2CH2)]+ and Its Release of Hydrogen. Issue 50 (16th October 2014)

• Record Type: Journal Article
• Authors: Girod, Marion; Krstić, Marjan; Antoine, Rodolphe; MacAleese, Luke; Lemoine, Jérome; Zavras, Athanasios; Khairallah, George N.; Bonačić‐Koutecký, Vlasta; Dugourd, Philippe; O'Hair, Richard A. J.
• Is Part Of: Chemistry. Volume 20:Issue 50(2014)
• Page Start: 16626
• Page End: 16633
• Publication Date: 2014-10-16
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201404110
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Multistage mass spectrometry and density functional theory (DFT) were used to characterise the small silver hydride nanocluster, [Ag<sub>3</sub>H<sub>2</sub>L]<sup>+</sup> (where L=(Ph<sub>2</sub>P)<sub>2</sub>CH<sub>2</sub>) and its gas‐phase unimolecular chemistry. Collision‐induced dissociation (CID) yields [Ag<sub>2</sub>HL]<sup>+</sup> as the major product while laser‐induced dissociation (LID) proceeds via H<sub>2</sub> formation and subsequent release from [Ag<sub>3</sub>H<sub>2</sub>L]<sup>+</sup>, giving rise to [Ag<sub>3</sub>L]<sup>+</sup> as the major product. Deuterium labelling studies on [Ag<sub>3</sub>D<sub>2</sub>L]<sup>+</sup> prove that the source of H<sub>2</sub> is from the hydrides and not from the ligand. Comparison of TD‐DFT absorption patterns obtained for the optimised structures with action spectroscopy results, allows assignment of the measured features to structures of precursors and products. Molecular dynamics "on the fly" reveal that AgH loss is favoured in the ground state, but H<sub>2</sub> formation and loss is preferred in the first excited state S<sub>1</sub>, in agreement with CID and LID experimental findings. This indicates favourable photo‐induced formation of H<sub>2</sub> and subsequent release from [Ag<sub>3</sub>H<sub>2</sub>L]<sup>+</sup>, an important finding in context of metal hydrides as a hydrogen storage medium, which can subsequently be released by heating or irradiation with light.</p> </abstract>