Syntheses and Structures of 5‐Membered Heterocycles Featuring 1,2‐Diphospha‐1,3‐Butadiene and Its Radical Anion

Abstract LGa(P 2 OC)cAAC 2 features a 1,2‐diphospha‐1,3‐butadiene unit with a delocalized π‐type HOMO and a π*‐type LUMO according to DFT calculations. [LGa(P 2 OC)cAAC][K(DB‐18‐c‐6)] 3 [K(DB‐18‐c‐6] containing the 1,2‐diphospha‐1,3‐butadiene radical anion 3 ⋅ − was isolated from the reaction of 2 with KC 8 and dibenzo‐18‐crown‐6. 3 reacted with [Fc][B(C 6 F 5 ) 4 ] (Fc=ferrocenium) to 2 and with TEMPO to [L −H Ga(P 2 OC)cAAC][K(DB‐18‐c‐6)] 4 [K(DB‐18‐c‐6] containing the 1,2‐diphospha‐1,3‐butadiene anion 4 − . The solid state structures of 2 , 3 K(DB‐18‐c‐6], and 4 [K(DB‐18‐c‐6] were determined by single crystal X‐ray diffraction (sc‐XRD).