(4-METHOXYPHENYLTELLURO)PROPANE-1,2-DIOL-SYNTHESIS AND REACTIONS WITHMERCURY(II), PALLADIUM(II) AND PLATINUM(II) HALIDES

The reaction of ArTe- Na+ (Ar = 4-MeOC6H4), generated in situ by boroh ydride reduction of Ar2Te2 under a nitrogen atmosphere, with CH2OH . C HOH . CH2Cl gave 3-(4-methoxyphenyltelluro)propane-1,2 diol (1). The r eactions of 1 with HgCl2, HgBr2, [PdCl2 (MeCN)2], K2[PtCl4], cis-[(PPh 3)2PdCl2] and cis-[(PPhl)2PtCl2] have been investigated. Complexes of the types [MX2.1]2, [MX2(1)2], [(Ph3P)2MCl(I)]ClO4 and [(Ph3P)2M(1)](C lO4)2 (M = Hg, Pd or Pt) were synthesized. In the H-1 NMR spectra of t he first three types of complexes, CH2-Te and aryl signals of 1 underg o a downfield shift of 0.3 to 0.7 ppm. This observation, in conjunctio n with no change in the position of nu(OH) and a red shift in nu[Te-C( aryl/alkyl)] bands in their IR spectra, suggests that 1 coordinates th rough tellurium only. The nu(Pd-Cl) band for [PdCl2(1)2] suggests a ci s-configuration. The last two species behave as 1 : 1 and 1 : 2 electr olytes, respectively. In [(Ph3P)2M(1)](ClO4)2 coordination of the liga nd 1 through Te and one OH group is possible, as indicated by the H-1 NMR and IR/far IR spectra. The P-31{H-1} spectra of [(Ph3P)2Pd(1)Cl]Cl O4 and [(Ph3P)2Pd(1)](ClO4)2 suggest that the two PPh3 groups of these species are cis to each other. 2J(P-Pd-P) was 22-26 Hz. Attempts to s tabilize metal diolates of palladium through chelation with telluruim did not succeed as the reaction between the disodium salt of I with [( CH3CN)2PdCl2] instantaneously gave elemental tellurium. The UV-vis spe ctra of palladium and platinum complexes support a square planar geome try of ligands.