2-(Phenyltelluromethyl)tetrahydrofuran (L1) and 2-(2-{4-methoxyphenyl}telluroethyl)-1,3-dioxolane (L2) and their palladium(II) and platinum (II) complexes

Article abstract of DOI:10.1016/S0277-5387(97)00203-9

The nucleophile [ArTe^-] generated in situ borohydride solution of Ar₂Te₂, reacts with 2-(chloromethyl)tetrahydrofuran and 2-(2-bromoethyl)-1,3-dioxolane resulting in L¹ and L², respectively. The complexes of palladium(II) and platinum(II) with L¹/L² having stoichiometries [MCl₂·L₂], [ML₂](ClO₄)₂, [(DPPE)ML₂](ClO₄)₂, [(PPh₃)₂ML₂](ClO₄)₂ and [(phen)ML₂](ClO₄)₂ (where L=L¹/L² DPPE=Ph₂PCH-₂CH₂PPh₂, phen=1,10-phenanthroline and M=Pd/Pt) have been synthesized. IR, ¹H, ¹²⁵Te{¹H} and ³¹P{¹H} NMR and UV-vis spectral data of these species in conjunction with their molar conductance and molecular weight data have been used to authenticate the new species. In all complexes (1-20) the ligands L¹ and L² are coordinated through tellurium and in the complexes of formula [ML₂](ClO₄)₂ (M=Pd, Pt) the ligand is bidentate with the oxygen atom used in complexation. In solution, complexes PtCl₂L₂ exist as a mixture of cis and trans isomers whereas only the trans isomer was observed for the palladium analogues. The [(phen)PdL₂](ClO₄)₂(Q) quenches ¹O₂ readily. The plot of log [Q] vs time is linear. Mechanism compatible with the experimental observations is proposed.