Deoxygenating Reduction of CO2 by [Cp*Al]4 to Form a (Al3O2C)2 Cluster Featuring Two Ketene Moieties

Inorg Chem. 2022 Sep 19;61(37):14500-14505. doi: 10.1021/acs.inorgchem.2c01587. Epub 2022 Sep 2.

Abstract

Herein we report that the reaction of the low-valent aluminum(I) species [Cp*Al]4 (Cp* = pentamethylcyclopentadienyl) with CO2 exhibits complete cleavages of the C═O bonds. The deoxygenating reduction reaction of [Cp*Al]4 with CO2 at 120 °C afforded [(Cp*)3Al3O2C(CO)]2 (1), which featured two stacked (Al3O2C)2 units and two C═C═O ketene moieties. Moreover, the isoelectronic analogues of diimine and isothiocyanate with CO2 were also investigated, and the reactions of [Cp*Al]4 with Dipp*-N═C═N-Dipp* and Dipp-C═N═S [Dipp* = 2,6-bis(diphenylmethyl)-4-tert-butylphenyl; Dipp = 2,6-diisopropylphenyl] afforded dialuminylimine (2) and tetrameric [Cp*AlS]4 (3), respectively.