20950-84-9Relevant academic research and scientific papers
Mechanisms of acid decomposition of dithiocarbamates. 2. Efficiency of the intramolecular general acid catalysis
Humeres, Eduardo,Debacher, Nito A.,Sierra, M. Marta De S.
, p. 1807 - 1813 (2007/10/03)
The acid decomposition of ethylenebis(dithiocarbamate) (EbisDTC) and glycinedithiocarboxylate (glyDTC) was studied in water at 25 °C in the range of rio -5 to pH 5. The acid dissociation constants of all species involved were calculated from LFER and from the pH-rate profiles. According to the pK(a) of the parent amine of the reactive species, both compounds decompose through the dithiocarbamate anion and a zwitterion intermediate. The intermolecular N-protonation rate constant of the carboxylic conjugate acid of glyDTC anion is 12.6 M-1 s-1, slower than the C-N breakdown. This species also cleaves through an intramolecular general acid-catalyzed mechanism where the rate constant for the N-protonation is (7.1 ± 4.2) x 103 s-1 and the efficiency of the proton-transfer step as measured by the effective molarity is (5.6 ± 3.3) x 102 M. The acid decomposition of the dithiocarbamic conjugate acid of EbisDTC anion proceeds through a fast N- protonation and a slower C-N breakdown. The intramolecular general acid catalysis rate constant is (8.2 ± 2.8) x 106 s-1, but the efficiency of this fast proton transfer is only (14.3 ± 4.9) M. The intramolecular general acid catalysis of the free acid forms of the carboxylic and dithiocarbamic groups is unfavorable for about 4 kcal mol-1 with respect to the protonation of the external hydron, and consequently, no external buffer catalysis is expected to be observed for dithiocarbamates that decompose through a zwitterion intermediate. The difference between the pK(b) of the proton acceptor and the pK(a) of the donor follows the order of the proton efficiency. Estimation of the strength of the hydrogen bonding in the reagent and product supports the assumption that a thermodynamically favorable change of hydrogen bonding from reagent to product increases the efficiency of proton transfer.
Ethylenediamine Monodithiocarbamate Complexes of Molybdenum
Nagaraja, K. S.,Udupa, M. R.
, p. 786 - 787 (2007/10/02)
Monodithiocarbamate of ethylenediamine(I) reacts with suitably generated molybdenum species in solution to give the solid complexes of the types Mo2S4(endtc)2 (II), MoO(NCS)(endtc)2 (III) and Mo(NO)2(endtc)2 (IV) (endtc = NH2CH2NHCSS).The oxidation state of molybdenum and stereochemistry of the complexes are inferred from the magnetic and spectral data.The IR and NMR spectral data of the complexes indicate the presence of free NH2 group and univalent bidentate nature of the dithiocarbamate ligand.The compound (II) is diamagnetic and its IR spectral bands at 540, 510, 470 and 340 cm-1 indicate the presence of Mo2S4(2+) core.The compound (III) is a mononuclear molybdenum(V) species with oxo, isothiocyanate and dithiocarbamate groups completing six coordination around molybdenum.The bands at 1745 and 1630 cm-1 in the IR spectrum of (IV) suggest that NO is coordinated as NO(+) and the two NO groups are cis to each other indicating the formal oxidation state of molybdenum to be zero.
Synthesis and radioprotective effects of disodium alkanebisdithiocarbamates, ω aminoalkyldithiocarbamic acids and their N,N dimethyl derivatives
Barnes,Fatome,Esslemont,et al.
, p. 619 - 622 (2007/10/04)
The 12 compounds studied containing the dithiocarbamate group, 5 of which are new, showed remarkably low acute toxicity in mice, with LD50 values generally higher than 1,000 mg/kg by the intraperitoneal route. Most noteworthy was 2 aminoethyldithiocarbamic acid, which protected 100% of mice against an LD99 of whole body γ-radiation in dose of 750 mg/kg, while the LD50 exceeds 1,500 mg/kg: certain higher homologues and N-methylated derivatives were also radioprotective and the series may merit further study.
