Pergamon zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Poly hedr on Vol. 13, No. 5, pp. 777-782, 1994 Coovr ieht 0 1994 zyxwvutsrqponmlkjihg Elsevier science Ltd Pcintedih &tBtitain. All rights reserved 0277-5387194 $6.OQ+O.O0 3-(4:METHOXYPHENYLTELLURO)PROPANE-1,2-DIOL- SYNTHESIS AND REACTIONS WITH MERCURY(II), PALLADIUM(I1) AND PLATINUMOr) HALIDES RAMAN BATHEJA, SEEMA KATIYAR, VEENA SINGH and AJAI K. SINGH* Department of Chemistry, Indian Institute of Technology, New Delhi 110 016, India (Received 2 1 June 1993 ; accepted 30 September 1993) Abstract-The reaction of ArTe-Na+ (Ar = 4-MeOC,$&), generated in situ by borohydride reduction of Ar,Te, under a nitrogen atmosphere, with CH20H - CHOH - CH2Cl gave 3- (4-methoxyphenyltelluro)propane-1,2 dial(1). The reactions of 1 with HgC12, HgBr,, pdC12 (MeCN),], K2[PtC14],cis-[(PPh,),PdC12] and cis-[(PPh3)2PtC12] have been investigated. Com- plexes of the types [MX2 - 112, [MX,(l),], [(Ph,P),MCl(l)]ClO, and [(Ph,P)2M(1)](C104)Z (M = Hg, Pd or Pt) were synthesized. In the ‘H NMR spectra of the first three types of complexes, CH,-Te and aryl signals of 1 undergo a downfield shift of 0.3 to 0.7 ppm. This observation, in conjunction with no change in the position of v(OH) and a red shift in v[Te-C(aryl/alkyl)] bands in their IR spectra, suggests that 1 coordinates through tellurium only. The v(Pd-Cl) band for [wCl,(l),] suggests a cis-configuration. The last two species behave as 1 : 1 and 1 : 2 electrolytes, respectively. In [(Ph3P)2M(1)](C104)2 coordination of the ligand 1 through Te and one OH group is possible, as indicated by the ‘H NMR and IR/far IR spectra. The 3’P{‘H} spectra of [(Ph,P),Pd(l)Cl]ClO, and [(Ph3P)2Pd(l)](C104)2 suggest that the two PPh3 groups of these species are cis to each other. ‘J(P-Pd-P) was 22-26 Hz. Attempts to stabilize metal diolates of palladium through chelation with telluruim did not succeed as .the reaction between the disodium salt of 1 with [(CH,CN),PdCld instantaneously gave elemental tellurium. The UV-vis spectra of palladium and platinum complexes support a square planar geometry of ligands. There is a current interest in the chemistry of organ- otellurium ligandslA as they are much less studied than their sulphur and selenium analogues. The ligation of hybrid organotellurium donors3 is even less explored, particularly of the type with oxygen as the donor atom along with tellurium. No attempt has been made to study the complexation of any (Te,02) ligand. It was, therefore, thought worth- while to synthesize 3-(4-methoxypheyltelluro)pro- pane-1,2-diol (l), which is potentially of this type, zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM *Author to whom correspondence should be addressed. and study its ligational behaviour with mercury(II), palladium(I1) and platinum(I1). 1 Since coordination with tellurium stablizes the alkoxides of platinum metals,’ which are otherwise prone to p-hydrogen elimination, it was thought worthwhile to examine whether such stabilization may be achieved for the metal diolates. The results of these investigations are reported in the present paper. 777