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

Abstract

The stepwise synthesis of novel As−Sb and As−Bi bond containing molecules is described. The binary interpnictogen compounds tBu2EAs(H)tBu (E=Sb (1), P (4)) were prepared by reaction of tBu2ECl with tBuAs(H)Li ⋅ 1,4-dioxane. Subsequent lithiation yields the dimeric compounds [tBu2EAsLi(thf)tBu]2 (E=Sb (2), E=P (5)). Compound 2 as well as tBu2SbAs(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 (tBu2PAs(tBu)E′tBu2 (E′=P (6), As (7), Sb (8), Bi (9)) and even four adjacent group 15 elements (tBu2PAs(tBu)E′′ (tBu)N(H)tBu (E′′=P (12), As (13), Sb (14)). Finally, the diarsane (tBu2PAstBu)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.