Dithiophosphates Dithiophosphoric Acid Diesters

Dithiophosphato metal complexes are usually prepared by metathesis of metal halides with alkali metal or ammonium salts. A convenient method uses the redox reaction of Ai5(thiophosphoryl)disulfanes (RO)2(S)PSSP(S)(OR)2, with metal species in low oxidation states resulting in the insertion of the metal into the sulf ur-sulfur bond. Recently it was used for the synthesis of long alkyl chain, liquid platinum(II) dithiophosphates and for the synthesis of Ru (CO)2[S2P(OPr%]2 from Ru3(CO)i2 with (Pr 0)2(S)PSSP(S)(OPr,)2.  

There are several representatives of Group 8 dithiophosphato complexes, including octahedral iron(III) derivatives Fe[S2P(OR)2]3 (R = Me, Pr% and the iron(II) complex Fe[S2P(OEt)2]2 Phen. Ruthenium and osmium are represented by mononuclear, paramagnetic pseudo-octahedral Ru [S2-P(0R)2]3, dinuclear [(RO)2PS2]2Ru (p-S)2Ru [S2P(OR)2]2 (R = Me, Et) 

Among the numerous nickel dithiophosphates, the chiral complexes deserve to be cited. Unusual trinuclear Pd3(p3-E)2[S2P(OR)2]2(PPh3)2 with E = S, Se, R = Et, Pr, Pr, Bu, have been prepared and Pd3(p3-S)2[S2P(OEt)2]2(PPh3)2 revealed a structure containing three distorted square-planar Pd atoms and sharing two p3-S ligands.  

A plethora of polynuclear copper(I) complexes with bi-, tri-, and tetracon-necting dithiophosphato ligands have been discovered. These include cyclic dimers, [CuS2P(OEt)2 PPh3]2, tetrahedral Cu4S2P(OPr )2]4, prismatic Cu6 S2P(OR)2 e, cubane Cu8(ng-E)[S2P(OEt)2]6 (E = S, Se), (also known for silver) and [Cu8 S2P(OPr%(Ps-X)][PF6] (X = Cl, Br). A supramolecular chain-like array of cubane units interconnected through iodine bridges was found in Cu8(S)[S2P(OEt)2]6(p-I), .  

A unique structure is that of the tetranuclear cation in [Ag4 S2P(OEt)2 3 (p-dppm)2] [X] (X = BF4, PFg), which contains three distinct coordination patterns of the dithiophosphato ligand, two of which are novel. Another fascinating structure is that of AgioS[S2P(OEt)2]8 based upon a distorted Agio monocapped quasi-prism, with bridging dithiophosphato ligands and an encapsulated sulfur atom in center of prism.  

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