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

Abstract

The reaction of compounds containing Al–Mg and Al–Zn bonds with N2O enabled isolation of the corresponding Al(μ-O)M complexes. Electronic structure analysis identified largely ionic Al–O and O–M bonds, featuring an...

The emerging chemistry of the aluminyl anion

“…We have recently examined the reactivity of Al–Zn and Al–Mg compounds 36 and 37 with CO 2 . 48 During this study we found that the Al–Zn compound reacts to form the dioxocarbene (NON)Al(O 2 C)Zn(BDI Mes ) 60 , with the same Type- B regiochemistry as that observed in the previous examples. In contrast, the Al–Mg compound immediately forms a carbonate complex (Type- D ), which was isolated as the trimetallic compound [Al(NON)(O 2 CO)] 2 [Mg(THF) 4 ] 61 , most likely the product of a Schlenk-type ligand redistribution.…”

“…We have recently examined the reactivity of Al-Zn and Al-Mg compounds 36 and 37 with CO 2 . 48 During this study we found that the Al-Zn compound reacts to form the dioxocarbene demonstrating that the m-oxo compounds are intermediates in the conversion of CO 2 to [CO 3 ] 2À .…”

“…More recently, an alternative (higher yielding) route to 34 was presented, 39 involving the reduction of ( xanth NON)Al–I with Jones’ Mg( i ) reagent, [(BDI Mes )Mg] 2 . 47 Related chemistry with potassium aluminyls 2 and 3 Dipp have afforded (NON)Al– M (BDI Mes ) ( 36 , M = Mg; 37 , M = Zn 48 ) and (NC 2 N Dipp )Al– M (BDI Dipp ) ( 38 , M = Mg; 39 , M = Ca 30 ) compounds.…”

Small‐Molecule Activation by Heteroleptic Metallasilylenes

“…Very recently, Coles et al. succeeded in the first isolation and structural characterization of such μ ‐oxo bridged Al−Zn and Al−Mg complexes, [21] which were found to react with CO 2 to carbonate‐bridged complexes. Complexes 3 and 4 are likely formed in a similar way via intermediate formation of a dioxocarbene‐bridged species, which forms L 1 (Cl)MOSiL 2 upon elimination of CO. L 1 (Cl)MOSiL 2 then react with CO 2 to the silanoic esters L 1 (Cl)MOSi(O)L 2 and finally with an additional equivalent of CO 2 to the carbonate complexes 3 and 4 , respectively (Scheme 2).…”

Hydroboration and Deoxygenation of CO2 Mediated by a Gallium(I) Cation

“…Nevertheless, when this solution was thoroughly ] and thus represents a rare example of a low-nuclearity group 13 oxide complex. 4,14,40,46,56 Degassed solutions of 4•BPh 3 react with CO 2 to form a new species, which is proposed to be the BPh 3 adduct of complex 3 (Scheme 3b). The same species was observed to form by reaction of 1 with CO 2 in the presence of BPh 3 (Scheme 3b, see SI for details).…”