- Copper-assisted desulfurization of 1-R-tetrazole-5-thiols under complexation
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The interaction of 1-R-tetrazole-5-thiols with copper(II) chloride in solution was found to yield crystalline tetrazole complexes [CuCl2L2]n (L is 1-R-tetrazole, R = Me, Et, Bu) and [CuCl2L2]n·nMeCN (L is 1-phenyltetrazole). The observed transformation of 1-R-tetrazole-5-thiols into 1-R-tetrazoles presents the first examples of desulfurization of tetrazole-5-thiols under complexation. A possible pathway of desulfurization of 1-R-tetrazole-5-thiols is proposed. It includes initial oxidation of tetrazole-5-thiols by copper(II) ions into bis(tetrazol-5-yl)disulfanes, followed by copper-assisted oxidation by air oxygen. Obtained complexes [CuCl2L2]n and [CuCl2L2]n·nMeCN were found to be coordination polymers, 2D and 1D, respectively. In all them, 1-R-tetrazoles act as monodentate ligands coordinated to the metal via the tetrazole ring N4 atom, whereas chlorine atoms provide bidentate bridging coordination to generate polymeric structure.
- Voitekhovich, Sergei V.,Lyakhov, Alexander S.,Ivashkevich, Ludmila S.,Ivashkevich, Oleg A.
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- Five new complexes based on 1-phenyl-1H-tetrazole-5-thiol: Synthesis, structural characterization and properties
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Five new complexes based on 1-phenyl-1H-tetrazole-5-thiol (Hptt): 1,1′-diphenyl-5,5′- dithiodi-tetrazole (abbreviated as dptt) (1), {[Co2(OH)2(2,2′-bipy)2(Hptt)2]·(ptt)2·(H2O)2}(2), [Cd2I2(2,2′-bipy)2(ptt)2] (3), [Co(ptt)2]n (4) and [Cd(ptt)2]n (5), have been synthesized and fully characterized by elemental analyses, thermogravimetric analysis, powder X-ray diffraction, IR spectra and single-crystal X-ray diffraction. Structural analysis indicated that compound 1 is an organic matter generated from in situ oxidative coupling reaction of Hptt ligands under the help of Fe3+ ion. In compound 2, two Hptt ligands adopting μ2-κN, κS bridging mode and two μ2-OHˉ bridge two Co(2,2′-bipy) fragments into a[Co2(OH)2(2,2′-bipy)2(Hptt)2]2+ core with short Co?Co distance (2.8185(10) ?). In compound 3, two Cd centers are joined into a dinuclear complex with short Cd?Cd distance (3.9282(14) ?) by two pttˉ anions in μ2-κS, κS bridging mode. Compounds 4 and 5 are isostructural and both feature one-dimensional (1D) looped chain structures containing 8-membered [M2S2C2N2] rings (M?=?Co for 4, M?=?Cd for 5). Variable-temperature magnetic susceptibility measurement of compounds 2 and 4 reveal strong antiferromagnetic interactions between Co centers. The fluorescent properties of compounds 1, 3 and 5 are investigated in the solid state.
- Song, Jiang-Feng,Wang, Jun,Li, Si-Zhe,Li, Yang,Zhou, Rui-Sha
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- Natural product inspired allicin analogs as novel anti-cancer agents
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A series of novel analogs of Allicin (S-allyl prop-2-ene-1-sulfinothioate) present in garlic has been synthesized in high yield. Synthesized 23 compounds were evaluated against different breast cancer cells (MDA-MB-468 and MCF-7) and non-cancer cells (WI38). Four compounds (3f, 3h, 3m and 3u) showed significant cytotoxicity against cancer cells whereas nontoxic to the normal cells. Based on the LD50 values and selectivity index (SI), compound 3h (S-p-methoxybenzyl (p-methoxyphenyl)methanesulfinothioate) was considered as most promising anticancer agent amongst the above three compounds. Further bio-chemical studies confirmed that compound 3h promotes ROS generation, changes in mitochondrial permeability transition and induced caspase mediated DNA damage and apoptosis.
- Bhaumik, Ishani,Pal, Kunal,Debnath, Utsab,Karmakar, Parimal,Jana, Kuladip,Misra, Anup Kumar
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p. 259 - 272
(2019/02/07)
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- Improved efficiency of CdS quantum dot sensitized solar cell with an organic redox couple and a polymer counter electrode
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Quantum dot sensitized solar cells (QDSSCs) based on an organic thiolate/disulfide redox couple (C7H5N4S-/C14H10N8S2or C2H3N4S-/C4H6N8S2) and a polymer counter electrode [poly (3, 4-ethylenedioxythiophene), PEDOT] were fabricated and their photovoltaic performance were investigated. In CdS QDSSC, the organic C7H5N4S-/C14H10N8S2electrolyte shows better performance than the polysulfide electrolyte, and the PEDOT counter electrode exhibits higher efficiency than that of the Pt counter electrode and the CoS counter electrode. An efficiency of 1.53% was achieved in this QDSSC. The influences of the morphology and the deposition charge of the PEDOT counter electrodes on the cell performance were also studied. Furthermore, it was found that the C7H5N4S-/C14H10N8S2redox couple outperformed the C2H3N4S-/C4H6N8S2redox couple due to reduced electron recombination.
- Shu, Ting,Li, Xiong,Ku, Zhi-Liang,Wang, Shi,Wu, Shi,Jin, Xiao-Hong,Hu, Chun-Di
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p. 700 - 704
(2014/12/11)
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- Efficient dye-sensitized solar cells with potential-tunable organic sulfide mediators and graphene-modified carbon counter electrodes
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A new class of organic sulfide mediators with programmable redox properties is designed via density functional theory calculations and synthesized for efficient dye-sensitized solar cells (DSCs). Photophysical and electrochemical properties of these mediators derived from systematical functionalization of the framework with electron donating and withdrawing groups (MeO, Me, H, Cl, CF3, and NO2) are investigated. With this new class of organic mediators, the redox potential can be fine-tuned over a 170 mV range, overlapping the conventional I-/I3-couple. Due to the suitable interplay of physical properties and electrochemical characteristics of the mediator involving electron-donating MeO group, the DSCs based on this mediator behave excellently in various kinetic processes such as dye regeneration, electron recombination, and mass transport. Thus, the MeO derivative of the mediator is identified as having the best performance of this series of redox shuttles. As inferred from electrochemical impedance spectroscopy and cyclic voltammetry measurements, the addition of graphene into the normal carbon counter electrode material dramatically improves the apparent catalytic activity of the counter electrode towards the MeO derivative of mediator, resulting in N719 based DSCs showing a promising conversion efficiency of 6.53% under 100 mW·cm-2 simulated sunlight illumination. Copyright
- Li, Xiong,Liu, Linfeng,Liu, Guanghui,Rong, Yaoguang,Yang, Ying,Wang, Heng,Ku, Zhiliang,Xu, Mi,Zhong, Cheng,Han, Hongwei
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p. 3344 - 3352
(2013/07/26)
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- Aerobic oxidation of some arylthiols catalyzed by a new manganese (III) schiff-base complex
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Bis(2-hydroxybenzene)phthaldiimine (BHBPDI) as a new quadridentate Schiff base ligand and its [Mn(III)(BHBPDI)Cl] complex were synthesized and characterized by analytical and spectral data (MS, FT-IR, UV-Vis, 1H NMR). The aerobic oxidation of thiols catalyzed by Mn(III)-complex using molecular oxygen was studied at room temperature. The reaction proceeded to yield the corresponding symmetric disulfides in good to high yields. The reaction was retarded when the reaction mixture was saturated with nitrogen gas. This system provides an efficient and convenient method for the oxidation of thiols to symmetric disulfides.
- Montazerozohori, Morteza,Fradombe, Leila Zamani
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experimental part
p. 509 - 515
(2010/06/17)
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- Fast and highly efficient solid state oxidation of thiols
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A fast and efficient solid state method for the chemoselective room temperature oxidative coupling of thiols to afford their corresponding disulfides using inexpensive and readily available moist sodium periodate as the reagent is described. The reaction was applicable to a variety of thiols giving high yields after short reaction times. Comparison of yield/time ratios of this method with some of those reported in the literature shows the superiority of this reagent over others under these conditions.
- Montazerozohori, Morteza,Joohari, Shiva,Karami, Bahador,Haghighat, Nasrin
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p. 694 - 702
(2008/02/01)
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- Nitric Acid Mediated Oxidative Transformation of Thiols to Disulfides
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Oxidation of thiols to disulfides are reported using nitric acid/methylene chloride. Environmentally benign, economically convenient and simple reaction condition represents an attractive alternative to the existing approaches on both the laboratory and the industrial scale.
- Misra, Anup Kumar,Agnihotri, Geetanjali
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p. 1079 - 1085
(2007/10/03)
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- Tetrazoles. XXXI. Phase-Transfer Reactions of 1-Substituted Tetrazole-5-thiones and Their Derivatives
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Alkylation of 1-substituted tetrazole-5-thiones under conditions of phase-transfer catalysis in the two-phase system liquid-liquid proceeds regioselectively at the sulfur atom, regardless of the alkylating agent and phase-transfer catalyst. Phase-transfer oxidation of the 5-alkylthiotetrazoles thus obtained by potassium permanganate is a convenient method for preparation of 5-alkylsulfonyltetrazoles which can be used to synthesize functionally substituted tetrazoles.
- Gol'tsberg,Koldobskii
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p. 1194 - 1201
(2007/10/03)
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