Dithiocarbazic acids

Dithiobenzoic acid metal complexes, 2, 646 colours, 2, 646 Dithiobiuret metal complexes, 2, 640 Dithiocarbamates chelating resins mineral processing, 6,826 Dithiocarbamic acid metal complexes, 2,585 amine exchange, 1,428 photographic emulsions, 6,98 nickel poisoning, 6,768 tellurium(Il) complexes photothermography, 6,121 Dithiocarbazic acid metal complexes, 2,803 Dithiocarbimic acid metal complexes, 2,588 Dithiocarbimic acid, cyano-metal complexes, 2,808 Dithiocarboxylic acids metal complexes, 2,646 Dithiodiacetic acid metal complexes, 2, 806 Dithiodiketones... 

Hydrazine reacts with carbon disulfide to yield dithiocarbazic acid [471-32-9] N2H4 + CS2 NH2NHCSSH... 

Neutral square planar complexes [NiLJ (339) with deprotonated thiosemicarbazide have been obtained by the direct reaction of the reagents in aqueous ammonia solution.2434 A summary of the spectroscopic studies carried out on the complexes with the various thiosemicarhazides is given in ref. 2470. Square planar complexes are also invariably given by deprotonated dithiocarbazic acids. The coordination mode (either S,S or N,S) adopted by these chelates depends on the substituents on the N atoms.2434,2445,2446... 

The nickel(II) complexes with thiosemicarhazides acting as neutral ligands, HL, are numerous and have been reviewed elsewhere.2415 Selected examples of square planar and six-coordinate complexes are given in Table 100. Some examples of complexes prepared with tridentate Schiff bases derived from either thiosemicarbazide or dithiocarbazic acid are given in Tables 97 and 98, and examples of complexes with bidentate Schiff bases are reported in Table 100. 

Dithiocarbazic acids R1R2NNR3CSSH form planar Ni(R1R2NNR3CSS)2 (R1, R2,R3 = H, alkyl, or aryl). n.m.r. spectra of a variety of these in DMSO solution were generally consistent with NS-co-ordination for unsubstituted and 2-substituted acids and SS-co-ordination for the 3-substituted complexes. The complexes with an [NiS2N2] chromophore produce evidence for cis-trans-isomers in solution.595... 

Condensation of ketones or aldehydes with the methyl ester of dithiocarbazic acid produces hgands with S,N,0 or S,N donor sets. An example is (142), which acts as both a didentate and a tridentate to ReO. Nickel(II)-templated reactions of pentanedione or salicylaldehyde with aminoethanethiol produce N,0,S ligands such as (143) and (144) these form simple mononuclear complexes or else dinuclear species with thiolate bridging two Ni centers. Mixed donor Schiff-base hgands including other heteroatoms such as P (145) and Te (146) have appeared. 

VII. Reaction of dithiocarbazic acids (hydrazines and carbon disulfide). . 624... 

Reaction of N-acyl dithiocarbazic acid esters. With hydrazines and... 

Young and Wood (389) did not isolate the intermediate benzoyl dithiocarbazic acids (LXXXII) which readily loose hydrogen sulfide on warming to yield the 5 substituted zl4-l,3,4-oxadiazoIine-2-thiones (LXXXIII). These authors suggested another reaction mechanism involving the intermediate formation of a xanthate type salt (LXXXVI) through nucleophilic attack of the enol form of the carboxylic acid hydrazide (LXXXIb) on carbon disulfide. 

The hydrazones of thiocarbohydrazides also react in this manner (304). The 5-amino-.d4-1,3,4-thiadiazoline-2-thiones, which may be prepared from thiosemicarbazides and carbon disulfide, are listed in Table 19-The preparation of these compounds from dithiocarbazic acid esters and isothiocyanates in basic medium is discussed in Section VII.7. It must be pointed out that the numbering of the substituents in Guha s paper (146) is not always very clear so that, for the last three substances in Table 19, there is some doubt about the position of the substituents. 

The ring closure reaction of a dithiocarbamate with a a-halo carbonyl compound gives rise to only a five-membered ring (thiazole). It must, however, be kept in mind that, in the ring closure of these substances (aldehydes, ketones, esters and acids) with a dithiocarbazic acid it is in principle possible to obtain 1,3,4-thiadiazine compounds (six-membered rings) as well as 3-amino thiazoles (five-membered rings). 

Both possibilities are, in fact, mentioned in the literature. The cyclization product of the ethyl chloroacetate with dithiocarbazic acid. 

Sato and Ohta (307) who reinvestigated the reaction of dithiocarbazic acids with chloroacetone and w-bromoacetophenone also described the 3.4-dihydro-2H-1,2,4-thiadiazine-2-thione structure to the products. These authors also describe the condensation of N-benzoyl dithiocarbazic acids (CCXV, Rj—CgHjCO with a-halo ketones which yields 4-benzoyl-3,4-dihydro-2H-t, 3,4-thiadiazine-2-thiones (CCXVIII, These products hydrolj ze in acid medium (with formation of benzoic acid) and simultaneously undergo a transformation to 3-amino-zl4-thiazoline-2-thiones. These facts support the remarks made earlier. 

There is certainly no doubt that the products of the reactions of chloroacetic acid with dithiocarbazic acids and with phenyldithiocarbazic acid, described by Mathes as perhydro-t,3,4-thiadiazin-5-one-2-thiones, are really 3-amino thiazohdin-4-one-2-thiones. Sandstrom s proof (302) of the structure of these substances was confirmed by Ueda and Otha (362) by chemical means and extended to other products. 3-amino-thiazolidin-4-one-2-thione, for instance, reacts with two moles of an aromatic aldehyde to give 3-benzylideneamino-5-benzylidenethiazolidin-4-one-2-thione (CCXII). 

Dithiocarbazic acids (CCXV) cyclize with isothiocyanates on simple warming to 5-imino-1,3,4-thiadiazolidine-2-thiones (CXVb) 70). Addition of alkali, however, causes the cyclization to follow a different path, or rather to give the classical transfer of an exocyclic nitrogen atom to a heterocyclic one or of a heterocyclic sulfur atom to an exocyclic thioxo group. This results in the formation of l,2,4-triazolidine-3,5-dithiones (CCXXXV) (Table 41). 

The reaction of dithiocarbazic acid esters (CCXXXVI) with isothiocyanates is more complicated in that the intermediate of the reaction, the ester of 1-(dithiocarboxy) thiosemicarbazide (CCXXXVII), can undergo ring closure to three kinds of substituted f,3,4-thiadiazole rings (62, JSO). 

Dithiocarbazic acid esters (CCXXXVI a) react with S-alkyl thiourea (CCXXXVIII) to form 3-amino-J2"f,2,4-triazoline-5-thiones (CCXXXIX) (276). 

The products of the reaction between carboxylic acid hydrazides and carbon disulfide cyclize very readily to Zl4-l,3,4-oxadiazoline-2-thiones (LXXXIII) (see Section II.7). The intermediates, the acyl- or benzoyl-dithiocarbazic acids may, however, also be isolated and reacted with alkyl halides to give S-alkyl dithiocarbazates (LXXXVIIIa) which also cyclize easily either to thiadiazoline or oxadiazoline rings according to the reaction circumstances (see Section II.7). 

Similarly, 6//(or 4//)-l,3,4-thiadiazine-2(3//)-thiones 13a-e and 14a, bean be prepared from the dimeric chloronitroso compounds 10 and the dithiocarbazic acid derivatives 11. The [3-ox-iminoalkyl dithiocarbazatcs 12 formed as intermediates can also be isolated.54... 

Diammonium dithlocarbazate DIthiocarbazIc acid, compound with hydrazine (V.1) Dithiocarbazic xid hydrazine (salt) Dithiooarbonio acid monohydrazide hydrazine salt EINECS 243-844-7 Hydrazinecarbodithioic acid, compd. with hydrazine (1 1) Hydrazinium dithlocarbazate NSC 512576. 

Dithiocarbazic acid (40d) forms 2 1 complexes with bivalent nickel, platinum, zinc, cadmium and lead, with trivalent rhodium, and a 3 1 complex with chromium(III). Electronic spectral details are consistent with N—S rather than S—S coordination. Similar donor behaviour is exhibited by a-N-substituted derivatives, although -N substituents may change the mode of coordination to S—S. S-Methyl derivatives are known to form stable complexes in both neutral and deprotonated forms, with bidentate N—S coordination being indicated." Recent X-ray analyses of Pd", Ni", Co" and Pt" S-methyl derivatives of dithiocarbazic acid verify this coordination mode. The Pd" chelate is cis planar" with a smaller tetrahedral distortion than was observed in a previously reported Ni" analogue. Three closely related tris chelates of Ni" were all reported to be distorted octahedral. 

Table 98 Complexes with SchiS Bases Derived from Pyridine-2-carbaldehyde, Thiosemicarbazide, Dithiocarbazic Acid and with Hydrazones... 

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