Synthesis and Characterisation of Molecular Bismuth Phosphorus Compounds Containing Bi2 Units with Bi–Bi Single and Double Bonds

The compound [BiP(SiPh2tBu)2]2 (1), featuring a Bi–Bi double bond and two Bi–P single bonds, has been obtained from thereaction of BiCl3 with the lithium phosphanide LiP(SitBuPh2)2.As a byproduct of this transmetallation/redox reaction the diphosphane P2(SitBuPh2)4 (2) has been isolated. This compound shows a remarkably short P–P bond due to π interactions of the phosphorus atoms. The reaction of the dilithium phosphandiide Li2PSitBuPh2 with BiCl3 yielded the bicyclic compound [Bi2(PSiPh2tBu)4] (3), exhibiting a Bi–Bi single bond. NMR studies of 3 show the availability of four different P atoms, as observed in the crystal structure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)