Hydride transfer to gold: yes or no? Exploring the unexpected versatility of Au···H-M bonding in heterobimetallic dihydrides
Hydride transfer to gold: yes or no? Exploring the unexpected versatility of Au···H-M bonding in heterobimetallic dihydrides
The potential for coordination and H-transfer from Cp2MH2 (M = Zr, W) to gold(I) and gold(III) complexes was explored in a combined experimental and computational study. [(L)Au]+ cations react with Cp2WH2 giving [(L)Au(κ2-H2WCp2)]+ (L = IPr (1), cyclic (alkyl)(amino)carbene (2), or phosphines PPh3 (3) and Dalphos-Me (4) [IPr = 1,3-bis(diisopropylphenyl)imidazolylidene; Dalphos-Me = di(1-adamantyl)-2-(dimethylamino)phenyl-phosphine], while [Au(DMAP)2]+ (DMAP = p-dimethylaminopyridine) affords the C2-symmetric [Au(κ-H2WCp2)2]+ (5). The Dalphos complex 4 can be protonated to give the bicationic adduct 4H, showing Au(I)…H+-N hydrogen bonding. The gold(III) Lewis acid [(C^N-CH)Au(C6F5)(OEt2)]+ binds Cp2WH2 to give an Au-H-W σ-complex. By contrast, the pincer species [(C^N^C)Au]+ adds Cp2WH2 by a purely dative W→Au bond, without Au···H interaction. The biphenyl-based chelate [(C^C)Au]+ forms [(C^C)Au(µH)2WCp2]+, with two 2-electron-3-centre W-H…Au interactions and practically no Au-W donor acceptor contribution. In all these complexes strong but polarised W-H bonds are maintained, without H-transfer to gold. On the other hand, the reactions of Cp2ZrH2 with gold complexes led in all cases to rapid H-transfer and formation of gold hydrides. Relativistic DFT calculations were used to rationalize the striking reactivity and bonding differences in these heterobimetallic hydride complexes along with an analysis of their characteristic NMR parameters and UV-Vis absorption properties.
bridging ligands, density functional calculations, gold, hydrides, tungsten
8267-8280
Rocchigiani, Luca
928f4dfb-8d8f-4902-830c-3a752e6e9259
Klooster, Wim
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Coles, Simon J.
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Hughes, David L.
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Hrobárik, Peter
60eae956-3239-4406-a78c-8c31939d1608
Bochmann, Manfred
ec2bb201-23cc-4f91-aa80-258e6c8cc9fb
2 July 2020
Rocchigiani, Luca
928f4dfb-8d8f-4902-830c-3a752e6e9259
Klooster, Wim
64dc0111-f415-4226-9189-45764c0933d9
Coles, Simon J.
3116f58b-c30c-48cf-bdd5-397d1c1fecf8
Hughes, David L.
d3b8245e-976a-47e6-8fe6-6ebcf38e2255
Hrobárik, Peter
60eae956-3239-4406-a78c-8c31939d1608
Bochmann, Manfred
ec2bb201-23cc-4f91-aa80-258e6c8cc9fb
Rocchigiani, Luca, Klooster, Wim, Coles, Simon J., Hughes, David L., Hrobárik, Peter and Bochmann, Manfred
(2020)
Hydride transfer to gold: yes or no? Exploring the unexpected versatility of Au···H-M bonding in heterobimetallic dihydrides.
Chemistry - A European Journal, 26 (37), .
(doi:10.1002/chem.202000016).
Abstract
The potential for coordination and H-transfer from Cp2MH2 (M = Zr, W) to gold(I) and gold(III) complexes was explored in a combined experimental and computational study. [(L)Au]+ cations react with Cp2WH2 giving [(L)Au(κ2-H2WCp2)]+ (L = IPr (1), cyclic (alkyl)(amino)carbene (2), or phosphines PPh3 (3) and Dalphos-Me (4) [IPr = 1,3-bis(diisopropylphenyl)imidazolylidene; Dalphos-Me = di(1-adamantyl)-2-(dimethylamino)phenyl-phosphine], while [Au(DMAP)2]+ (DMAP = p-dimethylaminopyridine) affords the C2-symmetric [Au(κ-H2WCp2)2]+ (5). The Dalphos complex 4 can be protonated to give the bicationic adduct 4H, showing Au(I)…H+-N hydrogen bonding. The gold(III) Lewis acid [(C^N-CH)Au(C6F5)(OEt2)]+ binds Cp2WH2 to give an Au-H-W σ-complex. By contrast, the pincer species [(C^N^C)Au]+ adds Cp2WH2 by a purely dative W→Au bond, without Au···H interaction. The biphenyl-based chelate [(C^C)Au]+ forms [(C^C)Au(µH)2WCp2]+, with two 2-electron-3-centre W-H…Au interactions and practically no Au-W donor acceptor contribution. In all these complexes strong but polarised W-H bonds are maintained, without H-transfer to gold. On the other hand, the reactions of Cp2ZrH2 with gold complexes led in all cases to rapid H-transfer and formation of gold hydrides. Relativistic DFT calculations were used to rationalize the striking reactivity and bonding differences in these heterobimetallic hydride complexes along with an analysis of their characteristic NMR parameters and UV-Vis absorption properties.
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Man_Rocchigiani_R1
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Accepted/In Press date: 26 February 2020
e-pub ahead of print date: 26 February 2020
Published date: 2 July 2020
Additional Information:
Funding Information:
This work was supported by the European Research Council. M.B. is an ERC Advanced Investigator Award holder (grant no. 338944‐GOCAT). Calculations were performed using the supercomputing infrastructure acquired in projects ITMS 26230120002 and 26210120002 supported by the Research & Development Operational Programme funded by the ERDF. PH also acknowledges financial support from the Slovak Grant Agencies VEGA (Grant No. 1/0712/18) and APVV (Grant No. APVV‐17‐0324) as well as from European Union's Horizon 2020 research and innovation program under the Marie Skłodowska–Curie Grant No. 752285. We acknowledge Dr. Florian Chotard and Dr. Alexander Romanov for a sample of (CAAC)AuCl. We thank the Engineering and Physical Sciences Research Council for funding the UK National Crystallography Service and Dr. Matthias Gutmann, ISIS, for help with the neutron data collection. Ad
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© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords:
bridging ligands, density functional calculations, gold, hydrides, tungsten
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Local EPrints ID: 438440
URI: http://eprints.soton.ac.uk/id/eprint/438440
ISSN: 0947-6539
PURE UUID: 5c3d596b-aadb-4399-b945-671441f79524
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Date deposited: 10 Mar 2020 17:31
Last modified: 17 Mar 2024 05:23
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Contributors
Author:
Luca Rocchigiani
Author:
Wim Klooster
Author:
David L. Hughes
Author:
Peter Hrobárik
Author:
Manfred Bochmann
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