Dialkylaluminium‐, ‐Gallium‐, and ‐Indium‐Based Poly‐Lewis Acids with a 1,8‐Diethynylanthracene Backbone

Abstract

Potential host systems based on a rigid 1,8-diethynylanthracendiyl backbone were synthesised by treatment of 1,8-diethynylanthracene with the Group 13 trialkyls AlMe(3), GaMe(3), InMe(3), AlEt(3) and GaEt(3). The resulting products were characterised by IR and multinuclear NMR spectroscopy, elemental analyses and determination of their crystal structures by X-ray diffraction. The compounds are dimeric in the solid state and comprise two M(2)C(2) heterocycles. Depending on the steric demand of the alkyl substituents at the metal atom, different types of binding modes were observed, which can be classified to lie between the ideals of side-on coordination with almost linear primary M-C≡C units and the 3c-2e coordination with symmetrically bridging alkynyl units in M-C-M bonds. As a solution in THF the dimers are broken into monomers and some are found to undergo ligand scrambling reactions.

Trans-Metal-Trapping Meets Frustrated-Lewis-Pair Chemistry: Ga(CH2SiMe3)3-Induced C–H Functionalizations

“…The 13 C NMR spectrum of 23 displayed two resonances at 104.7 and 105.4 ppm, which can be assigned to the Cα and Cβ positions, respectively, of the alkynyl fragment. 47 …”

Tridentate Lewis Acids: Boron‐, Silicon‐ and Gallium‐Functionalised Tris(dimethylsilyl)methanes

“…In most reports, the backbones of these molecules comprise flexible organic frameworks, because only a small number of donor-free rigid organic scaffolds are available. In the majority of cases the rigid backbones used are anthracenes functionalised with boron, [4] aluminium, [5] gallium [5] and indium, [5] but also naphthalenes functionalised with mercury, [6] boron [7,8] and other Lewis acid atoms. [7,9,10] Recently we reported some tridentate Lewis acids based on 1,3,5-trisilacyclohexane and equipped with boron, [11,12] gallium, [11,12] indium [12] and tin [13] functions.…”

1,8-Bis(phenylethynyl)anthracene – gas and solid phase structures

“…8 Like the parent anthracene, these compounds undergo photodimerisation reactions upon UV irradiation. 10 1,8-Bis( phenylethynyl)anthracene (1,8-BPEA) 11 carries two benzene rings in close proximity to one another. We recently reported for instance the application of 1,8-bis(diethylgallanylethynyl)anthracene as a bidentate Lewis acid, 9 and also as a derivative with aluminum and indium.…”