The preparation and coordination chemistry of phosphorus(III) derivatives of piperazine and homopiperazine

Reaction of piperazine or homopiperazine with R2PCl [R2=Ph2, OC2H4O, OC6H4O] gives six new bidentate phosphines. Simple bis-chelate and bridging complexes with demonstrative Mo(0), Pd(II), Pt(II) and Ru(II) centres are reported. The crystal structures of Ph2P(O)N(C2H4)2P(O)Ph2, cis-[PdCl2{Ph2PN(C2H4)2NPPh2}] (7) and cis-[PtCl2{Ph2PN(C5H10)NPPh2}][PtcodCl2]2 (15) are reported. In Ph2P(O)N(C2H4)2P(O)Ph2 the central N2C4 ring has a chair conformation and the P&z.dbnd6;O groups are trans. In 7 the piperazine backbone results in P&z.sbnd;Pd&z.sbnd;P bite angle of approximately 95° whilst in 15 the homopiperazine backbone enlarges the bite angle to 97°. [Copyright &y& Elsevier]