Picture of neon light reading 'Open'

Discover open research at Strathprints as part of International Open Access Week!

23-29 October 2017 is International Open Access Week. The Strathprints institutional repository is a digital archive of Open Access research outputs, all produced by University of Strathclyde researchers.

Explore recent world leading Open Access research content this Open Access Week from across Strathclyde's many research active faculties: Engineering, Science, Humanities, Arts & Social Sciences and Strathclyde Business School.

Explore all Strathclyde Open Access research outputs...

A structural and computational study of synthetically important alkali-metal/tetramethylpiperidide (tmp) amine solvates

Armstrong, D.R. and Graham, D.V. and Kennedy, A.R. and Mulvey, R.E. and O'Hara, C.T. (2008) A structural and computational study of synthetically important alkali-metal/tetramethylpiperidide (tmp) amine solvates. Chemistry - A European Journal, 14 (26). pp. 8025-8034. ISSN 0947-6539

Full text not available in this repository. Request a copy from the Strathclyde author

Abstract

Two heavy alkali-metal salts of the sterically demanding amine, 2,2,6,6-tetramethylpiperidine (TMPH), have been prepared using different methodologies. Complex 1, [{(tmeda)Na(tmp)}2] (TMEDA=N,N, N,N-tetramethylethylenediamine), can be synthesized by a deprotonative route. This is achieved by reacting butylsodium with TMPH in the presence of excess TMEDA in hexane. The potassium congener [{(tmeda)K(tmp)}2] (2), can be prepared by treating KTMP (made using a metathesis reaction between LiTMP and potassium tert-butoxide) with an excess of TMEDA in hexane. In the solid state, 1 and 2 are essentially isostructural. They are discretely dimeric and their framework consists of a four-membered M-N-M-N ring (M=Na or K, N=TMP). Due to the high steric demand of the TMP ligand, the TMEDA molecules bind to the metal centers in an asymmetric manner. In 2, each of the coordination spheres of the metals is completed by an agostic KCH3(TMP) interaction. DFT calculations at the B3 LYP/6-311G** level give an insight into why 1 and 2 adopt dramatically different structures from their previously reported, open-dimeric, lithium counterpart. The theoretical work also focuses on the TMEDA-free parent amide complexes and reveals that the energy difference for the formation of [{M(tmp)}x] (in which, M=Li or Na, x=3 or 4; and M=K, x=2, 3 or 4) are small. (Abstract copied from: http://www3.interscience.wiley.com/journal/120840676/abstract)