Palladium 1,1-dithio complexes

In nickel and palladium dithiobenzoato complexes, four-membered chelate rings are formed (366), whereas, in the corresponding phenyl-dithio acetates [M2(S2CCH2Ph)4], the dithio ligands act as bridging groups between the two metal atoms, with the formation of binuclear units (367). The molecular structure of the latter compounds shows that each metal atom is coordinated to four sulfur atoms and to the other metal atoms in a square-pyramidal geometry. Other evidence for... 

Considerably less is known about the chemistry of palladium and platinum 1,1-dithio complexes. Of late, there has been only one report that dealt with the synthesis of a large number of palladium dithiocar-bamates 392). Twenty-five yellow palladium dithiocarbamate complexes were obtained by reaction of PdCla with NaR2dtc in methanol solution. Several other reports have appeared in which a few dithiocarbamate complexes of palladium were synthesized. Thus, the novel [Pd (OH)2dtc 2], which is soluble in water, was isolated 393). The synthesis of optically active palladium(II) complexes of AT-alkyl-a-phen-ethyldithiocarbamates, similar to (XXIV), via the reaction between the optically active amine, CS2, and PdCl2, has been described. From ORD and CD spectra, it has been established that the vicinal contribution of a remote, asymmetric carbon center could give rise to optical activity of the d—d transitions of palladium 394). Carbon disulfide has been shown to insert into the Pt-F bond of [PtF(PPh3)3]HF2, and X-ray studies indicated the structure (XXIX). 

Selected Structural Parameters of the Palladium and Platinum 1,1-Dithio Complexes. 

Palladium forms complexes such as the dithio-oxalate ion, Pd(N2S2H)2, glyoximes, and phthalocyanine which are structurally similar to the compounds of Ni and Pt, and also numerous bridged compounds. Early X-ray studies established the planar trans configuration of (d) and (e) ... 

Palladium, Platinum, (a). Synthetic and Structural Studies. In the last 10 years, primary emphasis has been placed on the reaction chemistry of the 1,1-dithio Pd and Pt complexes. The crystal and molecular structure of the Pd(Et2 Dtc)2 complex has been reported (30). The compound is x-ray isomorph-ous to the Pt(II) analogue, for which the crystal structure was reported previously (12). The expected four-coordinate planar coordination of the Pd(II) ion is characterized by a Pd-S bond length of 2.316(3) A. 

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