Synthesis of Alumanyl Silyl Coinage Metal Complexes and their Reactivity Toward CO₂

Within this work, the straightforward synthesis of alumanyl silyl‐substituted coinage metal complexes (MCu ( 3a ), Ag ( 3b ), Au ( 3c )) from alumanyl silanide 1·Na·(DME) 2 and easily accessible N ‐heterocyclic carbene (NHC)‐stabilized coinage metal chlorides NHC‐M‐Cl (NHC = I i PrMe; MCu( 2a ), Ag( 2b ), Au( 2c )) is reported. Multinuclear nuclear magnetic resonance (NMR) spectroscopy and x‐ray diffraction (XRD) analysis reveal an increase of the SiM bond strength in 3a ‐ c descending the group. Consequently, regioselective insertion of CO 2 into the SiCu/SiAg bond of 3a and 3b is observed in addition to one molecule of CO 2 being inserted between the N ‐heterocyclic imine (NHI) ligand and the aluminum center yielding 4a and 4b . In case of 3c (Au), exclusive uptake of one CO 2 molecule by the NHI ligand is observed based on XRD analysis and multinuclear NMR analysis. The formation of 4a ‐ c was studied in detail with labeled 13 CO 2 .