A Free Aluminylene with Diverse σ‐Donating and Doubly σ/π‐Accepting Ligand Features for Transition Metals**

Abstract We report herein the synthesis, characterization, and coordination chemistry of a free N‐aluminylene, namely a carbazolylaluminylene 2 b . This species is prepared via a reduction reaction of the corresponding carbazolyl aluminium diiodide. The coordination behavior of 2 b towards transition metal centers (W, Cr) is shown to afford a series of novel aluminylene complexes 3 – 6 with diverse coordination modes. We demonstrate that the tri‐active ambiphilic Al center in 2 b can behave as: 1. a σ‐donating and doubly π‐accepting ligand; 2. a σ‐donating, σ‐accepting and π‐accepting ligand; and 3. a σ‐donating and doubly σ‐accepting ligand. Additionally, we show ligand exchange at the aluminylene center providing access to the modulation of electronic properties of transition metals without changing the coordinated atoms. Investigations of 2 b with IDippCuCl (IDipp=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene) show an unprecedented aluminylene‐alumanyl transformation leading to a rare terminal Cu‐alumanyl complex 8 . The electronic structures of such complexes and the mechanism of the aluminylene‐alumanyl transformation are investigated through density functional theory (DFT) calculations.