Synthesis and Characterization of Well‐Defined <i>s</i>‐Block Bis(Carbene) Complexes

Abstract Although the chemistry of monodentate N‐heterocyclic carbenes (NHCs) with s ‐block metals has been investigated, the coordination chemistry of phenyl dicarbene (CCC=bis(diisopropylphenyl‐imidazol‐2‐ylidenemethyl)phenyl) complexes remains largely underexplored. We report the synthesis and characterization of the free phenyl dicarbene precursors ( Br CCC Dipp and Br CCC Mes ) and the ensuing reactivity with Grignard reagents (3,5‐(CF 3 ) 2 ‐Ph)MgBr and MeMgCl to afford the cyclic dimeric complexes, ( Br CCC Dipp Mg3,5‐(CF 3 ) 2 PhBr) 2 , ( Br CCC Mes Mg3,5‐(CF 3 ) 2 PhBr) 2 , and ( Br CCC Dipp MgMeCl) 2 . Further exploration of various routes to activate the central C−Br bond of the ligands with alkali metals resulted in isolation of the respective NHC adducts of LiN(SiMe 3 ) 2 and KN(SiMe 3 ) 2 . Notably, these studies imply that flexibility of the pincer framework engenders dimeric complexes of s ‐block precursors over the monomeric complexes. The identity of the complexes was ascertained using multinuclear NMR spectroscopy and X‐ray crystallography.