2,5-Dimercapto-1,3,4-Thiadiazole(DMCT)-Based Polymers for Rechargeable Metal-Sulfur Batteries

Organosulfur materials are a sustainable alternative to the present-day layered oxide cathodes in lithium-based batteries.One such organosulfur material that was intensely explored from the 1990s to early 2010s is 2,5-dimercapto-1,3,4-thiadiazole(DMCT).However,research interest declined as the electrode reactions with DMCT were assumed to be too sluggish to be practical.Armed with the advances in metal-sulfur batteries,we revisit DMCT-based materials in the form of poly[tetrathio-2,5-(1,3,4-thiadiazole)],referred to as pDMCT-S.With an appropriate choice of electrode design and electrolyte,pDMCT-S cathode paired with a Li-metal anode shows a capacity of 715 mA h g^(-1)and a Coulombic efficiency of 97.7%at a C/10 rate,thus quelling the concerns of sluggish reactions.Surprisingly,pDMCT-S shows significantly improved long-term cyclability compared to a sulfur cathode.Investigations into the origin of the stability reveals that the discharge product Li-DMCT in its mesomeric form can strongly bind to polysulfides,preventing their dissolution into the electrolyte and shuttling.This unique mechanism solves a critical problem faced by sulfur cathodes.Encouragingly,this mechanism results in a stable performance of pDMCT-S with Na-metal cells as well.This study opens the potential for exploring other organic materials that have inherent polysulfide sequestering capabilities,enabling long-life metal-sulfur batteries.

Syntheses and Crystal Structures of Two Novel Cobalt(Ⅱ) Complexes with 2-Amino-5-substituted-1,3,4-thiadiazole as Ligands

Two novel cobalt（Ⅱ） compounds were obtained and characterized by X-ray sing- le-crystal diffraction, IR, 1H NMR and elemental analysis. Compound 1 crystallizes in monoclinic, space group P21/n, with a = 18.046（4）, b = 11.335（3）, c = 19.157（5）A, β = 92.707（3）°, Z = 4, V = 3914.4（16） A3, Mr = 968.56, Dc = 1.644 g/cm3, μ = 1.378 mm^-1, F（000） = 1960, the final R = 0.0367 and wR = 0.0895. The crystal of compound 2 is of monoclinic, space group P211c with a = 8.7253（10）, b = 10.9031（13）, c = 18.235（2）A,β = 93.2210（10）°, Z = 4, V = 1732.0（3）A3, Mr = 464.21, Dc = 1.780 g/cm3,μ = 1.560 mm-1, F（000） = 932, the final R = 0.0322 and wR = 0.0743.

Synthesis, Characterization and Crystal Structure of a Dinuclear Silver(I) Complex: [AgL(NO_3)]_2 (L= 2-Acetamido-5-methyl-1,3,4-thiadiazole)

The title complex [AgL（NO3）]2 1, where L = 2-acetamido-5-methyl-1,3,4-thiadiazole, was prepared from the reaction of 2-acetamido-5-methyl-1,3,4-thiadiazole with AgNO3 at room temperature and its structure has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P2t/c with a = 12.5454（8）, b = 11.9672（12）, c = 6.8925（6） A, β = 98.468（2）°. V= 1023.51（15） A^3, Mr= 3127.08, Dc = 2.123 g/cm^3, Z= 4, μ（MoKoσ） = 2.174 mm^-1, F（000） = 640, R = 0.0259 and wR = 0.0580 for 1787 observed reflections with I 〉 2σ（I）. Complex 1 self-assembls into a quasi-three-dimensional network consisting of adjacent dimers through intermolecular Ag...O weak interactions.

Microwave Assistant Synthesis and Dimeric Crystal Structure of 2-(((6-Chloropyridin-3-yl)-methyl)thio)-5-(pyridin-4-yl)-1,3,4-thiadiazole

The title compound 2-(((6-chloropyridin-3-yl)methyl)thio)-5-(pyridin-4-yl)-1,3,4-thiadiazole 5(C26H18Cl2N8S4) was synthesized, and its structure was confirmed by 1H NMR, MS and elemental analyses and X-ray diffraction. It crystallizes in the triclinic system, space group P1 with a = 9.452(4), b = 12.335(4), c = 13.017(5) A, α = 90.624(5), β = 110.541(5), γ =104.879(4)°, Dc = 1.561 g/cm3, Z = 2, V = 1364.9(9) A3, F(000) = 656, the final R = 0.0300 and w R = 0.0635 for 4206 observed reflections with I 】 2σ(I). The preliminary biological test showed that the title compound has activities against Stemphylium lycopersici(Enjoji) Yamamoto, Fusarium oxysporum. sp. cucumebrium, and Botrytis cinerea with inhibitory activities to be 9.82%, 44.44% and 20.00%, respectively.

Synthesis and antitumor activity of N^1-acetylamino-(5-alkyl/aryl-1,3,4-thiadiazole-2-yl)-5-fluorouracil derivatives

A new series of N^1-acetylamino-（5-alkyl/aryl- 1,3,4-thiadiazole-2-yl）-5-fluorouracil derivatives were designed and synthesized. These compounds have not been reported in literature, and their structure chemical were confirmed by IR, ^1H NMR and MS （HRMS）. The results of antitumor inhibitory activity test showed that some compounds possess more potent antitumor inhibitory activity than 5-fluorouracil.

Synthesis and Structure of 2-Isobutyl-6-(2',4'-dichlorophenyl)imidazo[2,1-b]-1,3,4-thiadiazole

The crystal structure of the title compound, 2-isobutyl-6-(2?4?dichlorophenyl)- imidazo[2,1-b]-1,3,4-thiadiazole (C14H13Cl2N3S, Mr = 326.23), has been synthesized by the treatment of 2-amino-5-isobutyl-1,3,4-thiadiazole with a-chloroaceto-2,4-dichlorophenone and determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 12.483(7), b = 8.420(4), c = 14.998(8) ? b = 105.770(10)? V = 1517.0(14) 3, Z = 4, Dc = 1.428 g/cm3, S = 0.902, m(MoKa) = 0.558 mm-1, F (000) = 672, R = 0.0579 and wR = 0.1186. The X-ray analytic results showed that all ring atoms in the imidazothiadiazole moiety are almost coplanar. The dihedral angel between the phenyl group and hetero-cycle is 16.8(0.2)?

Synthesis and Tribological Behaviour of 1,3,4-Thiadiazole Schiff Base Derivatives as Multifunctional Lubricant Additives

Six new 1,3,4-thiadiazole Schiff base derivatives were synthesized and characterized by IR spectroscopy and ~1H NMR spectrometry, and their anti-corrosion properties and thermal stability were investigated via thermogravimetric analysis(TGA) and copper strip corrosion test. The tribological behavior of the said Schiff base derivatives was evaluated on an Optimol SRV~?4 oscillating reciprocating friction and wear tester. The worn surfaces of the steel discs were investigated using a scanning electron microscope(SEM) and energy dispersive X-ray spectrometer(EDS). The test results indicated that these thiadiazole Schiff base derivatives possessed favourable thermal stability, corrosion inhibiting ability and the capability of improving the tribological characteristic of the base oil effectively. It is assumed that the adsorbed additives probably reacted with the steel surfaces during the friction process, resulting in the formation of a protective film composed of sulphates, sulphides and organic nitrogen compounds.

One-dimensional Zigzag Chain Composed of HgI_2 Unit and 2,5-Bis(4-pyridyl)-1,3,4-thiadiazole:[HgI_2(C_(12)H_8N_4S)]

The title compound, [HgI2（C12H8N4S）], has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 14.086（2）, b = 6.0365（6）, c = 20.286（2）°A,β= 108.818（5）°, V = 1632.7（3）°A^3, Mr = 694.67, Z = 4, D, = 2.826 g/cm^3,μ= 13.331 mm^-1, F（000） = 1240, S = 1.108, the final R = 0.0438 and wR = 0.0934 for 3085 observed reflections （I〉 2σ（I））. The Hg（Ⅱ） atom is coordinated by two 2,5-bis（4-pyridyl）-1,3,4-thiadiazole （L） molecules and two iodine anions in a distorted tetrahedral coordination geometry. Mercury atoms are linked by the organic ligands to form a one-dimensional zigzag chain. It is noteworthy that such 1D zigzag chains are extended into a two-dimensional double layer framework through I…I interactions

New Fungicidally Active Pyrazolyl-Substituted 1,3,4-Thiadiazole Compounds and Their Preparation

The potassium dithiocarbazate 2 was obtained through condensation of 5-pyrazole hydrazide 1 with carbon disulfide in ethanolic potassium hydroxide. and its cyclization gave 5-pyrazolyl-1,3,4-thiadiazole-2-thione 3 in concentrated sulfuric acid. Alkylation of 3 yielded 2-alkylthio-5-pyrazolyl-1,3,4-thiadiazole 4. The preliminary bioassay tests indicated that compounds 3 and 4 have fungicidal activity.

One-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles under ultrasonic irradiation

A facile one-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles was achieved by ultrasonic irradiation of a mixture of 1-naphthylacetyl chloride, NH4CNS, CH2Cl2 and PEG-400 for 1.5 h at 10–20 °C and subsequent irradiation for 1.5 h in the presence of N-arylglycine hydrazides. This method requires short time and gives thiadiazoles in high yields.

A novel series of 2,5-disubstituted 1,3,4-thiadiazoles as potential anticonvulsant agent

In pursuit for better antiepileptic drug and the importance of semicarbazones and 2,5-disubstituted 1,3,4-thiadiazoles as anticonvulsant pharmacophore, a series of novel N-（{5-[（6-methyl-l-benzofuran-3-yl）methyl]-l,3,4-thiadiazol-2-yl}carba- mothioyl）-2/3/4-substitutedbenzamide were designed, synthesized and evaluated for their anticonvulsant activity. The findings of the present studies confirmed that the pharmacophore model with four binding sites is crucial for anticonvulsant activity. Structure-activity relationships among synthesized compounds were also established.

Anti-tumor Metastasis and Crystal Structure of N^1-(1,3,4-Thiadiazole-2-yl)-N^3-m-chlorobenzoyl-urea

The title compound N1-（1,3,4-thiadiazole-2-yl）-N3-m-chlorobenzoyl-urea （C9HTN4OSC1, Mr = 254.70） was prepared by the reaction of m-chlorophenyl isocyanate with 2-amino-1,3,4- thiadiazole in dry acetonitrile. The effect of the title compound on tumor metastasis was analyzed by Lewis-lung-carcinoma model. The bioassay showed that the title compound significantly reduced the number of lung metastasis. The crystal structure has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 11.565（2）, b = 9.5616（19）, c = 10.221（2） A, β = 111.75（3）°, Z = 4, V= 1049.8（4） A3, De = 1.612 Mg/m3, F（000） = 520, g（MoKa） = 0.544 mm^-1, R = 0.0468 and wR = 0.0922 for 1236 observed reflections （I〉 2σ（I）.

Studies on Amidothiosemicarbazides and Related Hcterocyclic Derivatives ( XIII) --Synthetic Studies on 2-(3-Pyridyl)-5-Arylamino- 1,3, 4-Thiadiazoles and Oxadiazoles

By ring-closure of 1-nicotinyl-4-arylthiosemicarbazides under the catalysis of concentrated sulfuric acid or mercuric acetate, a series of 2-(3-pyridyl)-5-arylarnino-1,3,4-thiadiazoles and 2-(3-pyridyl)-5-ary-lamino-1,3,4-oxadiazoles were synthesized, respectively. All the products were subjected to testing of biological activity. Furthermore, the IR, 1H NMR and MS spectral properties of these new compounds were studied in details and some significant conclusions were drawn.

Synthesis, Crystal Structure and Bioactivities of 1-(4-Chlorophenyl)-3-[5-(pyrid-4-yl)-1,3,4-thiadiazol-2-yl]urea

The title compound 1-（4-chlorophenyl）-3-[5-（pyrid-4-yl）-1,3,4-thiadiazol-2-yl]urea （C14H10CIN5OS, Mr = 331.79） has been synthesized by the reaction of 2-amino-5-（pyrid-4-yl）- 1,3,4-thiadiazole with 4-chlorobenzoyl azide, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to triclinic system, space group PI with a = 5.8550（8）, b = 7.5668（10）, c = 16.416（2）A, α= 78.364（2）, β= 81.204（2）, γ= 84.749（2）°, V= 702.58（16）A^3, Z= 2, Dc = 1.568 g/cm^3, p = 0.429 mm ^-1, F（000） = 340, the final R = 0.0442 and wR = 0.1092 for 2001 observed reflections （1 〉 2σ（I））. X-ray diffraction analysis reveals that the title molecule is nearly planar. In the crystal structure, the molecules are linked by strong intermolecular N-H…N hydrogen bonds together with weak nonclassical intennolccular （C-H…Y, Y = N, O and CI） hydrogen bonds and stacked through π-π interactions. The preliminary bioassay shows that the title compound exhibits good fungicidal activities against Rhizoctonia solani, Botrytis cinerea and Dothiorella gregaria.

Synthesis, Crystal Structure and Antitumor Activity of N-(5-Aryl-1,3,4-thiadiazol-2-yl)-N?-((E)-styryl)ureas

N-(5-Aryl-1,3,4-thiadiazol-2-yl)-N?-((E)-styryl)ureas 4 a^4 i were designed and synthesized as antitumor agents, and their structures were characterized by IR, 1 H NMR, 13 C NMR,MS and elemental analysis. The single crystal of compound 4 a, C17 H13 FN4 OS, was also determined by X-ray crystallography. Crystal data: monoclinic, space group P21/n, a = 4.9401(8), b= 8.7100(15), c = 36.604(6) A,β= 93.320(3)°, V = 1572.4(5) A3, Z = 4, F(000)= 704, Dc = 1.438 g/cm3,μ= 0.228 mm-1, R = 0.0600 and wR = 0.1448 for 2743 independent reflections(Rint =0.0418) and 2174 observed ones(I > 2σ(I)). The in vitro antitumor activities of compounds 4 a^4 i were preliminarily evaluated by the standard MTT assay.

2-氨基-5巯基-1,3,4-噻二唑类席夫碱及其钼(Ⅵ)配合物的合成、表征及生物活性研究

合成了2-氨基-5-巯基-1,3,4-噻二唑与水杨醛、邻-香草醛缩合而成的席夫碱及其钼( )配合物,通过元素分析,IR,1HNMR,MS,UV-Vis光谱,摩尔电导等对所合成的化合物进行了表征,这类席夫碱合钼( )配合物尚未见文献报道.光谱研究表明配合物中金属钼离子为六配位,存在Cis-MoO22+结构.另外,还对配合物进行了杀灭棉铃虫活性及影响绿豆幼苗细胞存活率实验.实验表明配合物灭杀蚜虫和红蜘蛛的活性均高于甲胺磷,并对绿豆幼苗细胞有激活作用.

2,5-二羧甲硫基-1,3,4-噻二唑配合物的合成与表征

报道了配体2,5-二羧甲硫基-1,3,4-噻二唑和过渡金属铜(II)、镉(II)、钴(II)配合物的合成,经元素分析I、CP发射光谱、红外光谱、核磁共振谱、差热热重分析等方法对它们进行了表征,并对这些配合物进行了荧光性能的研究,结果表明镉和钴配合物具有荧光性.

N-[5-对氯苯基-1,3,4-噻二唑-2-基]-N'-苯甲酰脲的合成及生物活性研究(英文)

A new compound with biological activity had been synthesized by the reaction between 5-（p-chlorophenyl）-2-amino-1,3,4-thiodiazol and aroyl isocyanates.The structure of the target compound was confirmed by IR,UV,1HNMR spectrum and elemental analysis.The biological activity tests showed that the target compound had an activity as plant growth regulator,the auxin activity was 26.1% and the cytokinin activity was 41.1%.

新型可溶性2-(对辛氧基)苯基-5-(2-吡啶)-1,3,4-噁二唑-噻吩甲酰三氟丙酮-铕配合物的合成及其光致发光性能的研究

合成了新的第二配体2-(对辛氧基)苯基-5-(2-吡啶)-1,3,4-噁二唑(PAPO)及其铕配合物Eu(TTA)3(PAPO)。Eu(TTA)3(PAPO)在挥发性溶剂中具有好的溶解性,如溶于丙酮、氯仿,这意味着配合物可以甩胶成膜。热分析(TG)表明,配合物具有较高的热稳定性,有利于延长材料的使用寿命。在330nm的激发波长下,Eu(TTA)3(PAPO)的最强发射波长在615nm,这是铕离子的特征发射谱线,归属于5D0→7F2。从发光强度来看,Eu(TTA)3(PAPO)的光致发光(PL)产生了较强的红光,预示着它是一种比较理想的电致发光材料。