Carbon–chalcogen bond formation initiated by [Al(NON^Dipp)(E)]⁻anions containing Al–E{16} (E{16} = S, Se) multiple bonds

Abstract

Multiply bonded main group metal compounds are of interest as a new class of reactive species able to activate and functionalize a wide range of substrates. The aluminium sulfido compound...

Isolating elusive ‘Al(μ-O)M’ intermediates in CO2reduction by bimetallic Al–M complexes (M = Zn, Mg)

“…This is further supported by low WBI (Al–O) values ( 4-Zn = 0.372; 4-Mg = 0.426) when compared with the [Al(NON Dipp )(O)] − anion (WBI (Al–O) = 1.11). 23 Moreover, we note that the values of ρ ( r ) are similar to that of the monomeric [Al(NON Dipp )(O)] − anion ( ρ ( r ) = 0.115 e Å −3 ; ∇ 2 ρ ( r ) = 0.990 e Å −5 ), 23 indicating that the terminal M (BDI Mes ) group only minimally perturbs the charge density and electronic composition of the Al–O bond. A more pronounced difference is observed for the O– M BCPs in each compound.…”

Synthesis and Reactivity of an Aluminyl Anion

“…However, DFT studies revealed that as the chalcogenides get heavier the degree of multiple bonding tends to increase. 83 The exposure of the sulfide and selenide to an atmosphere of 13 CO2 resulted in the formation of the corresponding heavy carbonate complexes B-1.86-S and B-1.86-Se, similar to those observed by the related alumoxane complexes (Scheme 1.17). 83 However, the terminal telluride was identified to proceed through a heavy carbonate intermediate ("B-1.86-Te"), before undergoing another insertion of 13 CO2 to afford B-1.87-Te.…”

“…83 The exposure of the sulfide and selenide to an atmosphere of 13 CO2 resulted in the formation of the corresponding heavy carbonate complexes B-1.86-S and B-1.86-Se, similar to those observed by the related alumoxane complexes (Scheme 1.17). 83 However, the terminal telluride was identified to proceed through a heavy carbonate intermediate ("B-1.86-Te"), before undergoing another insertion of 13 CO2 to afford B-1.87-Te. 84 The addition of CS2 to B-1.81 was shown to form B-1.88, which forms via a [2+2]-cycloaddition across the "Al=S" bond.…”

“…In this respect, our research group has had success in the synthesis and subsequent reactivity of these species using aluminyl B-1.3. 80,[82][83][84] The addition of elemental sulphur to B-1.3, regardless of the stoichiometry used in the reaction, was found to give the 1,2,3,4,5-tetrathiaaluminyl complex B-1.80. 80 Extraction of three S atoms from B-1.80 was possible using triphenylphosphine to afford the terminal aluminium sulfide compound, B-1.81.…”

“…80 Extraction of three S atoms from B-1.80 was possible using triphenylphosphine to afford the terminal aluminium sulfide compound, B-1.81. 83 In contrast, the reaction between B-1.3 with an excess of elemental selenium gave a heavy dioxirane analogue, B-1.82. 82 To isolate the terminal aluminium selenide complex B-1.83, one equivalent of Se (per Al) was added to B-1.3 in the presence of a catalytic transfer reagent (P n Bu3).…”