BISMUTH(III) CHLORIDE COMPLEXATION WITH DIPHOSPHINE AND DIARSINE OXIDE LIGANDS - FORMATION AND CRYSTAL-STRUCTURES OF [BICL3(PH(2)P(O)CH2P(O)PH(2))](2) ICL3(AS(O)MEPH(2))(PH(2)AS(O)CH2CH2AS(O)PH(2))](N)

The reactions of bismuth(III) chloride and Ph(2)PCH(2)PPh(2) (dppm) an d Ph(2)AsCH(2)CH(2)AsPh(2) (dpae) have been studied. The yellow produc ts isolated initially were characterised by spectroscopic (H-1 and P-3 1 NMR, IR) and microanalytical data as the 1:1 addition compounds BiCl 3.dppm and BiCl3.dpae respectively. Recrystallisation of these product s from boiling acetonitrile/charcoal effected oxidation of the ligands and resulted in the formation of two new molecular adducts whose stru ctures have been determined by X-ray crystallography. Crystals of [BiC l3{Ph(2)P(O)CH2P(O)Ph(2)}](2) 1 are triclinic, space group P $($) over bar$$ 1 with Z = 2. There are two independent centrosymmetric molecul es in the unit cell with similar. edge-edge shared bioctahedral struct ures. Each bismuth centre is six-co-ordinate with approximal octahedra l geometry being bonded to two terminal chlorine atoms, two bridging c hlorine atoms and two:oxygen:(ligand) atoms. In situ ligand oxidation dppm-->Ph(2)P(O)CH2P(O)Ph(2) occurs and the resulting bidentate. (00') chelation gives rise to puckered six-membered Bi-O-P-C-P-O ring forma tion. Crystals of [BiCl3{As(O)MePh(2)}{Ph(2)As(O)CH2CH2As(O)Ph2}](n) a re monoclinic, space group P2(1)/a with Z = 4. The structure consists of one-dimensional polymeric chains. Here the in situ ligand oxidation is more complex and results in the formation of two arsine oxide liga nds. viz. dpae-->Ph(2)As(O)CH2CH2- As(O)Ph(2) + As(O)MePh(2) both of w hich are involved in co-ordination to Bi-III. Each bismuth atom is bon ded in an approximately mer-octahedral arrangement to three terminal c hlorine atoms and three oxygen (ligand) atoms. Of the latter, one is p rovided by a monodentate As(O)MePh, molecule and the other two by sepa rate Ph(2)As(O)CH2CH2As(O)Ph(2) molecules which, by virtue of their bi dentate bridging mode, are linked to adjacent metal centres.