@article{be0841db44ab4cc690dfb4af106bd5a2,
title = "Lithium Complexes with Bridging and Terminal NHC Ligands: The Decisive Influence of an Anionic Tether",
abstract = "Deprotonation of the fluorenyl-tethered imidazolinium salt [9-(C13H9)C2H4N(CH)C2H4N(2,4,6-Me3C6H2)][BF4] gave a spirocyclic compound that reacted with a synergic mixture of LiPh/LiN(SiMe3)2 or LinBu/LiN(SiMe3)2 to give a dilithium complex incorporating a bridging N(SiMe3)2 ligand. In contrast, deprotonation of the imidazolium salt [9-(C13H9)C2H4N(CH)C2H2N(Me)][Br] instead yielded the free NHC, which reacted with nBuLi to form a dimeric, NHC-bridged dilithium complex. Addition of LiN(SiMe3)2 led to coordination and the formation of a dilithium complex with a bridging N(SiMe3)2 ligand, which was characterised in the solid state as a 1D coordination polymer. The reaction of 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene (SIPr) with lithium indenide and lithium fluorenide gave soluble species with terminal binding of the NHC to the lithium cation and η5 coordination of indenyl or fluorenyl. A symmetrical bridging mode for an NHC donor was therefore observed only if a tethered fluorenyl anion was present with no additional amide ligand.",
keywords = "Bridging coordination, Carbene ligands, Fluorenyl tethers, Indenyl tethers, Lithium",
author = "Evans, {Kieren J.} and Campbell, {Cameron L.} and Haddow, {Mairi F.} and Christian Luz and Morton, {Paul A.} and Mansell, {Stephen M.}",
note = "Funding Information: We would like to thank the EPSRC (DTP studentship to K. J. E.), the Daphne Jackson Trust (Fellowship to M. F. H.) and Heriot-Watt University for funding. C. L. was an Erasmus exchange student from the Julius-Maximilians-Universit{\"a}t W{\"u}rzburg, Germany. We thank the EPSRC UK National Mass Spectrometry facility at Swansea University for collecting mass spectrometry data, Dr G. Nichol (University of Edinburgh) for collecting single-crystal X-ray diffraction data for 3 and 6, and Dr D. Ellis for help with NMR spectroscopy. Funding Information: We would like to thank the EPSRC (DTP studentship to K. J. E.), the Daphne Jackson Trust (Fellowship to M. F. H.) and Heriot‐Watt University for funding. C. L. was an Erasmus exchange student from the Julius‐Maximilians‐Universit{\"a}t W{\"u}rzburg, Germany. We thank the EPSRC UK National Mass Spectrometry facility at Swansea University for collecting mass spectrometry data, Dr G. Nichol (University of Edinburgh) for collecting single‐crystal X‐ray diffraction data for 3 and 6, and Dr D. Ellis for help with NMR spectroscopy. Publisher Copyright: {\textcopyright} 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.",
year = "2019",
month = nov,
day = "13",
doi = "10.1002/ejic.201901003",
language = "English",
volume = "2019",
pages = "4894--4901",
journal = "European journal of inorganic chemistry",
issn = "1434-1948",
publisher = "Wiley-VCH",
number = "46",
}