Bidentate dithiophosphates

Analogous to the dithiophosphate complexes, cis octahedral complexes are formed with bident-ate ligands like phenanthroline, 2,2 -bipyridine, or tmeda and trans octahedral complexes are formed with monodentate ligands like pyridine and its derivatives. Some examples are mentioned with linear bidentate ligands like 4,4 -bipyridine, which build up ID chains by bridging the [NiL2] molecules.926-933... 

Two significant general results of the structural data thus far reported are (1) dithiophosphate, S2P(OR)2, groups can behave as mono- and bidentate ligands and (2) substitution of one R group for another usually leads to changes... 

Distorted ZnS4tetrahedra Zn-S 2.345,2.337,2.351 and 2.401 A One dithiophosphate bidentate One dithiophosphate bridges Zn atoms Infinite polymers... 

One dithiophosphate bidentate One dithiophosphate bridging Helical chain polymer Mercury five-coordinate... 

For Te[S2P(OCH3)2l2 the ligand has been found to be monodentate 1 ). With zinc(II) and cadmium(II) complexes the ligand, O, O -di-isopropyl-dithiophosphate, has been shown to be both bidentate and bridging 178) xhe irregular pentagonal bipyramidal structure of... 

Another important class of bidentate ligands in gold chemistry are those composed of sulfur donor ligands such as dithiocarbamates, dithiolates, dithiocarboxylates, dithiophosphinates, dithiophosphates, and so on. The complexes prepared with these ligands are generally of the type Au2(p.-SS)(PR3)2]"+ or Au2(p-SS)(p-PP)] [153-155], [Au2(p-SS)2f [156, 157] or Au3( i-SS)2(PPh3)2 [158]. All these... 

Homoleptic gold(III) derivatives with dithiolate, ligands of the type [Au(S-S)2] are well known and are usually prepared from [AuC14] with the dithiol some examples are with 1,2-benzene dithiolate, maleonitriledithiolate, dmit, and so on, [164, 336]. Similar complexes have been reported for bidentate sulfur ligands such as dithiocarbamates, dithiophosphates, and so on, [41]. Other derivatives as the trinuclear species [Au(C6F5)(S2C6H4)]3 [337] or the complex with one nido and one closo-carborane dithiolate are known [338]. Figure 1.72 collects some of these complexes. 

Values of the normalized bite b and the twist angle 8 for these complexes are given in Table 14. In sharp contrast to other tris(chelate) complexes, it is very clear that 8 is not a simple function of b. In all cases 8 is lower than predicted, and in many cases the trigonal prism with 8 = 0° is observed. These dithiolate ligands are clearly different from other bidentate ligands, even other sulfur donors such as MeSCH=CHS, dithioacetylacetonate, dithiooxalate, dithiophosphates, dithiocarbamates and xanthates. 

Single crystal X-ray structural analyses of these compounds3,4 show that the tellurium atom is surrounded by four sulfur atoms from four different dithiophosphate groups in a planar arrangement. The S —P —S group is not a bidentate ligand but serves as a bridge between tellurium atoms. 

Bidentate S donor ligands dithiocarbamates, dithiophosphates, 1,1-and 1,2-dithiolates, etc. 

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