Heavy Chains: Synthesis,Reactivity and Decomposition of Interpnictogen Chains with Terminal Diaryl Bismuth Fragments

In this work, we report the preparation of multiple interpnictogen chain compounds with three consecutive pnictogen atoms and terminal Ar₂Bi fragments (Ar=Ph, Mes). Symmetrical compounds of the form Ar₂Bi?E(tBu)?Bi₂Ar ( 1 : Ar=Ph, E=P; 2 : Ar=Ph, Mes, E=As) as well as ternary interpnictogen compounds of the form Ar₂Bi?E¹(tBu)?E²tBu₂ (Ar=Ph, Mes; 4 : E¹=P, E²=As; 5 : E¹=P, E²=Sb; 6 : E¹=As, E²=P) were prepared. The decomposition in solution at room temperature and under the influence of light was studied for compounds 1 – 6 . The reactivity of 1_Ph and 2_Ph with the small N-heterocyclic carbene 1,3,4,5-tetramethylimidazol-2-ylidene (Me₂IMe) was also studied. In the case of 1_Ph , the formation and consecutive decomposition of Me₂IMe=PtBu ( 8 ) was observed in solution. Hence, it was shown that 1_Ph can react as a “masked phosphinidene”. In the case of 2_Ph , no reaction with Me₂IMe was observed. All isolated compounds were analysed by NMR and IR spectroscopy, mass spectrometry, elemental analysis and single-crystal X-ray diffraction.