Symmetric and non-symmetric anthracen-diyl bis(alkylidynes). Issue 43 (22nd October 2021) - Frogley, Benjamin J.
Abstract : This first anthracene mono- and bis(carbyne) complexes are reported including symmetrical (palindromic) and unsymmetrical examples with disparate metal and co-ligand termini. Abstract : Three examples of 9-bromo-10-(alkylidynyl)anthracenes, [W{CC(C6 H4 )2 CBr}(CO)2 (L)] (L = hydrotris(dimethylpyrazol-1-yl)borate Tp*, hydrotris(pyrazol-1-yl)borate Tp, hydrotris(2-mercapto- N -methylimidazol-1-yl)borate Tm) were prepared via modified Fischer-Mayr acyl oxide-abstraction protocols. With a sufficiently bulky ancillary ligand (L = Tp*) the aryl bromide is ammenable to cross-coupling reactions that enable more elaborate derivatives to be prepared. These including symmetric bis(alkylidynyl)anthracenes as well as non-palindromic examples bearing disparate metals and/or co-ligands. In contrast, these couplings fail for smaller ligands (L = Tp, Tm) where it was found that Pd 0 or Pt 0 were instead able to coordinate across two WC bonds to give trimetallic bow-tie complexes, [W2 M{μ-CC(C6 H4 )2 CBr}2 (CO)4 (L)2 ] (M = Pd, Pt; L = Tp, Tm).