1,3,5-Trithiocyanuric acid

Dimercapto-l,3,4-thiadiazole derivatives, accelerated by amines, are used to cross-link chlorinated polyethylene. Polyisobutylene containing brominated i ra-methylstyrene cure functionahty can be cross-linked in polymer blends with dimercapto-1,3,4-thiadiazole derivatives accelerated with thiuram disulfides. Trithiocyanuric acid is suggested for use in polyacrylates containing a chlorine cure site and in epichlorohydrin mbbers. 

Curing Systems. The most commonly used vulcanizing agent for the polyethers not containing AGE, that is, ECH and ECH—EO, is 2-mercaptoimidazoline, also called ethylenethiourea [96-45-7]. Other commercially appHed curing agents include derivatives of 2,5-dimercapto-l,3,4-thiadiazole, trithiocyanuric acid and derivatives, bisphenols, diamines, and other substituted thioureas. 

Trithiocyanuric acid gives the trinuclear derivatives [Au3(S3C3N3)L3] (L = PPh3, Bu NC, P(OMe)3, P(OPh)3, PCy3), that by loss of one ligand L yields the hexanuclear species [Au6(S3C3N3)L4] (536) (L = PPhMe2, Bu NC).2960,2961 The mononuclear compound... 

Another material that has a strong propensity to form solvate structures in crystallization experiments is trithiocyanuric acid (TTCA). Consequently, the pure crystalline phase of TTCA is difficult to obtain by crystallization from solution, but can be obtained instead by desolvation of these solvate phases. In this... 

Trithiocyanuric Acid, (HCNS)3, may be obtained by treating cyanuric chloride with sodium sulphide.8 It forms yellow needles, stable up to 200° C., soluble in water. At 200° C. hydrochloric acid transforms it into cyanuric acid. 

In general, the thiones are not very reactive. Trithiocyanuric acid decomposes on heating above 200 °C, and is hydrolyzed to cyanuric acid and hydrogen sulfide in hydrochloric acid at 200 °C. Melamine is produced in 40% yield on heating trithiocyanuric acid with ammonia under pressure (59HC(l3)l,p.l05). Garmaise has reported the formation of the disulfide derivatives (52) (66CJC1801). 

Organic inclusion compounds and dathrates have been known for a long time. While these compounds are still being investigated, there have been efforts to synthesise novel organic structures by supramolecular means.30 A recent example in this direction is the noncovalent synthesis of a novel channel structure formed by trithiocyanuric acid and bipyridine.301 The channels can accommodate benzene, xylenes and other molecules (Fig. 12) and the process is reversible. 

Fig. 12 Noncovalent synthesis of a layered network with large cavity based on hydrogen bonding between trithiocyanuric acid and bipyridine. Three-dimensional channels with benzene molecules can be seen [from Pedireddi et al. (reproduced with permission from ref. 30(6))].

An organic channel structure formed by the supramolecular assembly of trithiocyanuric acid and 4,4 -bipyridyl CO CD... 

Trithiocyanuric acid (TCA) and 4,4 -bipyridyl (BP) form hydrogen-bonded co-crystals with aromatic compounds such as benzene, toluene, /7-xylene and anthracene. The TCA-BP co-crystal is composed of cavities formed by the N-H - N hydrogen bonds between the two molecules, and the three-dimensional structure contains channels of approximately 10 A where aromatic molecules are accommodated. The molar ratios of TCA, BP and the aromatic compound in the co-crystals are 2 1 1 or 2 1 0.5. Benzene, toluene and /7-xylene are removed from the channels around 190, 183 and 170 °C respectively, and these aromatic guests can be reintroduced into the empty channels of the apo-hosts. The apo-hosts with empty channels have reasonable thermal stability and exhibit shape selectivity in that the empty channels accommodate /7-xylene but not m- or o-xylene or mesitylene. 

The stable organic solid containing channels formed by the supramolecular hydrogen-bonded assembly of trithiocyanuric acid and 4,4 -bipyridyl can accommodate aromatic molecules such as benzene, toluene and /7-xylene. The apo-host is thermally stable up to 200 °C and exhibits shape selectivity with respect to the xylene isomers. The channels do not accommodate mesitylene. It would be interesting to carry out chemical reactions in these channels. 

Hydrothermal Synthesis of Organic Channel Structures 1 1 Hydrogen-Bonded Adducts of Melamine with Cyanuric and Trithiocyanuric Acids... 

Figure 2. (a) Hexagonal network (rosette) formed between trithiocyanuric acid (TCA) and Melamine (M) in the adduct of TCA-M with a cavity diameter of approximately 4 A. (b) Three-dimensional arrangement of the TCA-M adduct forming channels along crystallographic c-axis. 

Rao et al. recently reported a related structure that is based upon modular self-assembly 59 an organic network formed by trithiocyanuric acid (TCA) and bipy. Adjacent layers are aligned parallel to each other and there is no interpenetration. The resulting open framework structure exhibits channels with an effective diameter of 10 A. An interesting feature of this compound is that the cavities in the layers, and therefore the channels, can vary in size depending on the solvent of crystallization that is used to template the modular self-assembly process. (Scheme 8). It should be noted that the two architectures are not simply distorted or stretched variants of one another, they have distinct hydrogen-bonding patterns. Another salient feature is that there are sulfur atoms accessible in the cavities, which could... 

Kimura and co-workers have prepared a novel self-assembled cage composed of four trimeric Zn(II)-cyclen complexes joined with four tri-deprotonated trithiocyanuric acid molecules in aqueous solution. The 4 4 complex is thermo-... 

The tautomerism of 1,3,5-triazines has been reviewed previously (B-76MI22000, pp.138,152,168). NMR and IR studies have shown that cyanuric acid exists mainly in the oxo form. Although the cyanurates and isocyanurates are the two major derivatives, there is no doubt that compounds with both types of functional group present in the same molecule are possible (e.g. Scheme 36). Trithiocyanuric acid exists predominantly in the thioamido form. In contrast, melamine exists in the amino form. /S-Oxoalkyl-1,3,5-triazines exist mainly in the enol form, and thus they undergo ene type reactions with dienophiles. 

A significant decrease of the efficiency was observed when the resin was recycled, together with a coloration of the resin, possibly due to contamination with the palladium catalyst (Pd(PPhj)4). This observation was subsequently verified in the cross-coupling of supported aryltins with 2-halogenopyridines by washing the resin with trithiocyanuric acid, which led to a recovery of the cross-coupling efficiency at least on the first reuse. ... 

Trithiocyanuric acid (TTCA s-triazine-2,4,6-trithiol) is a cyclic analog of thio-... 

Thiourea Sodium salt trithiocyanuric acid (Na TTCA)... 

To address this concern, several organic and inorganic reagents were evaluated as precipitants for heavy metals in a 10-34-0 (N-P2O5-K2O) fluid fertilizer and WPA. Trisodium trithiocyanuric acid (TMT-15), sodium polythiocarbonate (Thio-Red II), and sodium trithiocarbonate (5% Na2 CS3) precipitated arsenic, cadmium, copper, mercury, lead, and zinc from 10-34-0. Ammonium cyanurate was ineffective in removing cadmium from 10-34-0. Thio-Red II and 5% Na2CS3 precipitated mercury, lead, cadmium, copper, and chromium from WPA. A water-insoluble starch xanthate adsorbed mercury, copper, and lead from 10-34-0 and WPA. Sodium sulfide, sodium polysulfide, and potassium ferrocyanide were tested as inorganic precipitants. The polysulfide was twice as effective as the sulfide alone, and concentrations of less than 10 ppm of arsenic, cadmium, mercury, and lead were achieved in 10-34-0. Ferrocyanide reduced the concentrations of cadmium and nickel to less than 10 ppm in WPA. 

Finally, it should be noted here that highly acidic wastewaters (pH <1) will precipitate the acid form of TMT-15, trithiocyanuric acid. In fact, our preliminary tests confirmed that trithiocyanuric acid was indeed formed upon addition of TMT-15 to WPA (pH <1). Consequently, only the chemistry of TMT-15 with 10-34-0 will be discussed in a later section. The pH values of 10-34-0 are typically in the range of 6.2-6.9. 

Trithiocyanuric Acid (TMT-15). Literature obtained from the manufacturer stated that TMT-15 would precipitate copper, cadmium, mercury, silver, lead, nickel, and tin from wastewater, after adjusting the pH value to within certain ranges (20). Trivalent metals, such as iron, chromium, and aluminum, will not precipitate upon addition of TMT-15. 

The analytical results from the precipitation and adsorption tests conducted with Thio-Red II, 5% Na2CS3, and the WI starch xanthate on WPA containing additional cadmium, copper, lead, manganese, and mercury are summarized in Table III. As mentioned previously, addition of TMT-15 to WPA results in the precipitation of trithiocyanuric acid no heavy metals are coprecipitated. 

---