Hydrogen Generation by Water Reduction with [Cp*2Ti(OTf)]: Identifying Elemental Mechanistic Steps by Combined In Situ FTIR and In Situ EPR Spectroscopy Supported by DFT Calculations. Issue 41 (17th September 2013)

• Record Type: Journal Article
• Authors: Hollmann, Dirk; Grabow, Kathleen; Jiao, Haijun; Kessler, Monty; Spannenberg, Anke; Beweries, Torsten; Bentrup, Ursula; Brückner, Angelika
• Is Part Of: Chemistry. Volume 19:Issue 41(2013)
• Page Start: 13705
• Page End: 13713
• Publication Date: 2013-09-17
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201301598
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A detailed mechanism of hydrogen production by reduction of water with decamethyltitanocene triflate [Cp*₂Ti^III(OTf)] has been derived for the first time, based on a comprehensive in situ spectroscopic study including EPR and ATR‐FTIR spectroscopy supported by DFT calculations. It is demonstrated that two H₂O molecules coordinate to [Cp*₂Ti^III(OTf)] subsequently forming [Cp₂*Ti^III(H₂O)(OTf)] and [Cp*Ti^III(H₂O)₂(OTf)]. Triflate stabilizes the water ligands by hydrogen bonding. Liberation of hydrogen proceeds only from the diaqua complex [Cp*Ti^III(H₂O)₂(OTf)] and involves, most probably, abstraction and recombination of two H atoms from two molecules of [Cp*Ti^III(H₂O)₂(OTf)] in close vicinity, which is driven by the formation of a strong covalent TiOH bond in the resulting final product [Cp*₂Ti^IV(OTf)(OH)].</p> </abstract>