Smith, Dan A., Beweries, Torsten, Blasius, Clemens et al. (8 more authors) (2015) The Contrasting Character of Early and Late Transition Metal Fluorides as Hydrogen Bond Acceptors. Journal of the American Chemical Society. pp. 11820-11831. ISSN 1520-5126
Abstract
The association constants and enthalpies for the binding of hydrogen bond donors to group 10 transition metal complexes featuring a single fluoride ligand (trans-[Ni(F)(2-C<inf>5</inf>NF<inf>4</inf>)(PR<inf>3</inf>)<inf>2</inf>], R = Et 1a, Cy 1b, trans-[Pd(F)(4-C<inf>5</inf>NF<inf>4</inf>)(PCy<inf>3</inf>)<inf>2</inf>] 2, trans-[Pt(F){2-C<inf>5</inf>NF<inf>2</inf>H(CF<inf>3</inf>)}(PCy<inf>3</inf>)<inf>2</inf>] 3 and of group 4 difluorides (Cp<inf>2</inf>MF<inf>2</inf>, M = Ti 4a, Zr 5a, Hf 6a; Cp<inf>2</inf>MF<inf>2</inf>, M = Ti 4b, Zr 5b, Hf 6b) are reported. These measurements allow placement of these fluoride ligands on the scales of organic H-bond acceptor strength. The H-bond acceptor capability β (Hunter scale) for the group 10 metal fluorides is far greater (1a 12.1, 1b 9.7, 2 11.6, 3 11.0) than that for group 4 metal fluorides (4a 5.8, 5a 4.7, 6a 4.7, 4b 6.9, 5b 5.6, 6b 5.4), demonstrating that the group 10 fluorides are comparable to the strongest organic H-bond acceptors, such as Me<inf>3</inf>NO, whereas group 4 fluorides fall in the same range as N-bases aniline through pyridine. Additionally, the measurement of the binding enthalpy of 4-fluorophenol to 1a in carbon tetrachloride (?23.5 ± 0.3 kJ mol<sup>-1</sup>) interlocks our study with Laurence's scale of H-bond basicity of organic molecules. The much greater polarity of group 10 metal fluorides than that of the group 4 metal fluorides is consistent with the importance of p?-d? bonding in the latter. The polarity of the group 10 metal fluorides indicates their potential as building blocks for hydrogen-bonded assemblies. The synthesis of trans-[Ni(F){2-C<inf>5</inf>NF<inf>3</inf>(NH<inf>2</inf>)}(PEt<inf>3</inf>)<inf>2</inf>], which exhibits an extended chain structure assembled by hydrogen bonds between the amine and metal-fluoride groups, confirms this hypothesis.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 American Chemical Society |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) The University of York |
Funding Information: | Funder Grant number EPSRC EP/J012955/1 THE HIGHER EDUCATION COMMISSION UNSPECIFIED |
Depositing User: | Pure (York) |
Date Deposited: | 09 Feb 2017 15:20 |
Last Modified: | 04 Dec 2024 00:11 |
Published Version: | https://doi.org/10.1021/jacs.5b07509 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1021/jacs.5b07509 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:112197 |