Phosphine‐Stabilized Pnictinidenes

The reaction of the intramolecular germylene‐phosphine Lewis pair (o‐PPh(2))C(6)H(4)GeAr* (1) with Group 15 element trichlorides ECl(3) (E=P, As, Sb) was investigated. After oxidative addition, the resulting compounds (o‐PPh(2))C(6)H(4)(Ar*)Ge(Cl)ECl(2) (2: E=P, 3: E=As, 4: E=Sb) were reduced by using sodium metal or LiHBEt(3). The molecular structures of the phosphine‐stabilized phosphinidene (o‐PPh(2))C(6)H(4)(Ar*)Ge(Cl)P (5), arsinidene (o‐PPh(2))C(6)H(4)(Ar*)Ge(Cl)As (6) and stibinidene (o‐PPh(2))C(6)H(4)(Ar*)Ge(Cl)Sb (7) are presented; they feature a two‐coordinate low‐valent Group 15 element. After chloride abstraction, a cyclic germaphosphene [(o‐PPh(2))C(6)H(4)(Ar*)GeP] [B(C(6)H(3)(CF(3))(2))(4)] (8) was isolated. The (31)P NMR data of the germaphosphene were compared with literature examples and analyzed by quantum chemical calculations. The phosphinidene was treated with [iBu(2)AlH](2), and the product of an Al−H addition to the low‐valent phosphorus atom (o‐PPh(2))C(6)H(4)(Ar*)Ge(H)P(H)Al(C(4)H(9))(2) (9) was characterized.