Preparation and characterisation of [Pt{N(SePPh2)2-Se,Se′}(PR3)2]Cl (R = alkyl or aryl); crystal structure of [Pd{Ph2PNP(Se)Ph2-P,Se}{N(SePPh2)2-Se,Se′}]·0.5EtOH·0.3CH2Cl2

Reaction of NH(PPh(2))(2) with selenium gives Ph(2)P(Se)NHP(Se)Ph(2) which may be deprotonated with KOBu(t) to give K[Ph(2)P(Se)NP(Se)Ph(2)]. This can be treated with appropriate Group VIII metal complexes to give [Rh{N(SePPh(2))(2)}(cod)] (cod = cycloocta-1,5-diene), a series of complexes of formula [Pt(N(SePPh(2))(2)-Se,Se')(PR(3))(2)]Cl (PR(3) = PMe(3), PMe(2)Ph, PEt(3), PPh(3), 1/2NH(PPh(2))(2) or 1/2Ph(2)PCH(2)CH(2)PPh(2)) and [MCl{N(SePPh(2))(2)-Se,Se'}(PMe(2)Ph)] (M = Pt or Pd). The new compounds have been characterised by P-31 and Pt-195 NMR and IR spectroscopy, FAB(+) mass spectrometry and microanalyses. Furthermore, a small quantity of a mixed-ligand complex [Pd{Ph(2)PNP(Se)Ph(2)-P,Se}{N(SePPh(2))(2)-Se,Se'}]. 0.5EtOH . 0.3CH(2)Cl(2) has been characterised by X-ray crystallography and P-31 NMR spectroscopy. Its structure reveals an approximately planar five-membered PdSeP2N ring and a puckered six-membered PdSe2P2N ring. in the crystal the molecules pack with channels which contain the disordered CH2Cl2 molecules running down the a direction.