Investigation on Arsenic-Antimony- and Arsenic-Bismuth Bond Containing Interpnictogen Chain Molecules

The stepwise synthesis of novel As-Sb and As-Bi bond containing molecules is described. The binary interpnictogen compounds tBu(2)EAs(H)tBu (E=Sb (1), P (4)) were prepared by reaction of tBu(2)ECl with tBuAs(H)Li . 1,4-dioxane. Subsequent lithiation yields the dimeric compounds [tBu(2)EAsLi(thf)tBu](2) (E=Sb (2), E=P (5)). Compound 2 as well as tBu(2)SbAs(tBu)SiMe3 (3) are not suitable as synthons for longer chains due to non-selective reactions. In contrast, compound 5 was successfully used for the preparation of chains with three (tBu(2)PAs(tBu)E ' tBu(2) (E '=P (6), As (7), Sb (8), Bi (9)) and even four adjacent group 15 elements (tBu(2)PAs(tBu)E '' (tBu)N(H)tBu (E ''=P (12), As (13), Sb (14)). Finally, the diarsane (tBu(2)PAstBu)(2) (15) was synthesised by reaction of 5 with 1,2-dibromoethane. The obtained compounds were characterised by mass spectrometry, multinuclear NMR spectroscopy, IR spectroscopy and by single crystal X-ray diffraction in the case of 2, 5-9 and 12-15.

Automated summary

The stepwise synthesis of novel molecules containing As-Sb and As-Bi bonds was achieved by reacting tBu(2)ECl with tBuAs(H)Li to prepare binary interpnictogen compounds, followed by lithiation to obtain dimeric compounds. Compound 5 was found to be suitable for the preparation of longer chains, and the synthesis was confirmed through experiments.