Syntheses and characterization of new dithiophosphinato zinc complexes

Abstract

Four known dithiophosphinic acids, DTPA, were synthesized and their zinc complexes werenewly prepared. The complexes have been proven to have the structures [Zn(μ-DTPAn)2(DTPAn)2],([DTPAn]= Rn(R)P(S)H, R= 4-CH3O-C6H4-; R1= iso-amyl-, DTPA1; R2= iso-butyl-, DTPA2; R3= sec-butyl-,DTPA3; R4= iso-propyl-, DTPA4). The DTPAs were prepared by the reaction of the Lawesson reagent,[2,4–bis(4-methoxyphenyl)–1,3,2,4–dithiodiphosphetane–2,4–disulfide] (LR), with the correspondingGrignard compounds. The acids formed are viscous liquids difficult to purify and so they were convertedto ammonium salts, [DTPAn][NH4], which are easy to obtain as pure crystals. The complexes wereidentified to have dimeric structures on the basis of mass spectroscopic data.