Arsenic, dithiocarbamate complexes

Haywood and Riley " found that As(III) can be separated from As(V) even at levels of 2 jgl, by extracting it as the pyrrolidine dithiocarbamate complex with chloroform. They applied this technique to samples of seawater spiked with As(V) and As(III) and found that arsenic(V) could be satisfactorily determined in the presence of arsenic(III). 

Inorganic Derivatives.- 1,6-Anhydro 2-chloro-2,4-dideoxy-4-(diphenylphosphoryl)-P-D-glucopyranose, the P-in-the-ring sugar analogues (27) and (28)," the natural arsenic-containing riboside (29), methyl 4,6-0-benzylidene-3-deoxy-3-C-triphenylstannyl-a-D-altropyranoside, two isomeric chromium(III) complexes with 1,3,5-triamino-1,3,5-trideoxy-cw-inositol in the one structure, the vanadium(in) complex (30),and the platinum(Il)-dithiocarbamate complex (31). ... 

The homoleptic tris(dithiocarbamate) complexes [M(S2CNR2)3] (M = As, Sb, or Bi) have been studied extensively (93, 212-245). The arsenic complexes are mononuclear with three short As—S bonds (As—S = 2.31-2.39 A) that are essentially cis each other, and three long As—S bonds (As—S = 2.77-2.94 A). Valence bond sum (VBS) calculations show that the valency of the As atom is, as expected, close to three (224). The geometry at arsenic in the [As(S2CNR2)3] is best described as a distorted octahedron with the stereochemically active lone pair directed along the pseudo threefold axis, capping the triangular face defined by the three weakly coordinated S atoms (Fig. 16) (222-224, 230). 

The structural chemistry of some metal dithiocarbamates, i.e. systematics, coordination modes, crystal packing, and supramolecular self-assembly patterns of nickel, zinc, cadmium, mercury,363 organotin,364 and tellurium,365 366 complexes has been thoroughly analyzed and discussed in detail. Supramolecular self-assembly frequently occurs in non-transition heavier soft metal dithiocarbamates. Thus, lead(II),367 bismuth(III)368 zinc,369 cadmium,370 and (organo)mercury371 dithiocarbamates are associated through M- S secondary bonds, to form either dimeric supermolecules or chain-like supramolecular arrays. The arsenic(III)372 and antimony(III)373 dithiocarbamates are... 

The chemistry of inorganic arsenic complexes with ligands that bear S donor atoms or S and O is more extensive. The chemistry of arsenic with xanthate (41), dithiocarbamate (42) and phosphorus based ligands (43) (Figure 12) has been reviewed. ... 

Antimony has a great affinity for charged sulfur ligands which include thiolates, xanthates (R0CS2 ), dithiocarbamates (R2NCS2 ), and dithiophosphates ((RO)2PS2 ). In contrast to arsenic, where this chemistry is limited to oxidation state III, antimony forms compounds in oxidation states III and V. The xanthate, dithiocarbamate, and dithiophosphate complexes are mostly made by reaction of antimony(III) halides or organohalides with Na, NH4, or Ag salts of the acids. Complexes... 

Spectrophotometric methods using Na-DDTC are rather insensitive since the colours of metal complexes with DDTC are not intense. Complexes with Cu, Bi, and Mn are among the most intensely coloured diethyl dithiocarbamates. The yellowish Ag-DDTC is used in the determination of arsenic (reaction with ASH3, see Section 8.2.2). Fig. 19.1 shows the absorption spectra of some metal diethyldithiocarbamates. 

Gallium(III) complexes, 129 amines, 129 amino acids, 141 arsenates, 135 borates, 134 borohydrides, 141 bromates, 135 carbonates, 134 caiboxylates, 135 chlorates, 135 citrates, 136 cyanides, 129 dithiocarbamates, 138 ethers, 136 fluorides, 138 germanates, 134 hydrides, 140 iodates, 135 p-ketoenolates, 134 lactates, 136 mixed halides, 139 molybdates, 135 nitrates, 135 peptides, 141 perchlorates, 135... 

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