From As ‐Zincoarsasilene (LZn‐As=SiL′) to Arsaethynolato (As≡C−O) and Arsaketenylido (O=C=As) Zinc Complexes

The reactivity of the As‐zincosilaarsene LZn−As=SiL′ A (L=[CH(CMeNDipp) 2 ] − , Dipp=2,6‐ i Pr 2 C 6 H 3 , L′=[{C(H)N(2,6‐ i Pr 2 ‐C 6 H 3 )} 2 ] 2− ) towards small molecules was investigated. Due to the pronounced zwitterionic character of the Si=As bond of A , it undergoes addition reactions with H 2 O and NH 3 , forming LZnAs(H)SiOH(L′) 1 and LZnAs(H)SiNH 2 (L′) 2 . Oxygenation of A with N 2 O at −60 °C furnishes the deep blue 1,2‐disiloxydiarsene, [LZnOSi(L′)As] 2 4 , presumably via dimerization of the arsinidene intermediate LZnOSi(L′)As 3 . Oxygenation of A with CO 2 leads to the monomeric arsaethynolato siloxido zinc complex LZnOSi(L′)(OC≡As) 5 , essentially trapping the intermediary arsinidene 3 with liberated CO following initial oxidation of the Si=As bond. DFT calculations confirm the ambident coordination mode of the anionic [AsCO] ligand in solution, with the O‐arsaethynolato [As≡C−O] .− in 5 , and the As‐arsaketenylido ligand mode [O=C=As] − present in LZnO−Si(L′)(−As=C=O) 5′ akin to the analogous phosphorus system, [PCO] − .