Dehydrogenation of Ar*BiH₂ 3 yielded the kinetically stabilized mono-coordinated triplet bismuthinidene 4, which was structurally characterized by sc-XRD and whose electronic character was analyzed by quantum chemical calculations. Bismuthinidene 4 reacts with alkyl halides with oxidative addition to bismuthanes Ar*Bi(R)X, which react with LiAlH₄ to the corresponding room temperature-stable bismuthanes Ar*Bi(R)H.

Abstract

The triplet bismuthinidene Ar*Bi (4) stabilized by a very bulky septiphenyl ligand (Ar* = 3,5-i-Pr₂-2,6-(2,6-Me₂-3,5-(2,6-i-Pr₂C₆H₃)₂–C₆H)–C₆H) was synthesized by dehydrogenation of in situ formed bismuth dihydride Ar*BiH₂ (3). Oxidative addition reactions of 4 with alkyl halides (MeI, EtBr, i-PrBr) yielded bismuthanes Ar*Bi(Me)I (5), Ar*Bi(Et)Br (6), and Ar*Bi(i-Pr)Br (7), which reacted with LiAlH₄ and LiAlD₄ to the thermally robust bismuth monohydrides Ar*Bi(R)H (R = Me 8, Et 10, i-Pr 12) and monodeuterides Ar*Bi(R)D (R = Me 9, Et 11, i-Pr 13). Ar*Bi(NMe₂)₂ 1 and Ar*BiH₂ 3 were characterized in situ by ¹H NMR spectroscopy and sc-XRD (1), whereas the other compounds were characterized by heteronuclear NMR (¹H/²H (D), ¹³C) and IR spectroscopy, elemental analysis (Ar*-2, Ar*-3, Ar*-5, Ar*-7, Ar*I, Ar*H, 2, 4−7), as well as by UV–vis (4) and sc-XRD (Ar*-7, Ar*I, Ar*Li·Lit-Bu, Ar*H, 1, 2, 4, 12). Quantum chemical calculations revealed the triplet character of the bismuthinidine 4.