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.

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.

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

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)?

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.

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-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.

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.

Studies on Condensed Heterocyclic Compounds(Ⅲ)——Synthesis and Antibacterial Activity of 3-(4-Pyridyl)-6-Alkyl/Aromatic Heterocyclyl-s-Triazolo[3,4-b]-1, 3,4-Thiadiazoles and 1,4-Bis [6-(4-Pyridyl)-s-Triazolo [3,4-b]-1, 3,4-Thiadiazol-3-yl]-n-Butane

In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemists and pharmacologists because they show broad spectra of biological activities, such as antifungal, antibacterial, hy-

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.

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）.

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.

Synthesis,Characterization and Crystal Structure of 3-o-Fluorophenyl-6-(4-decarboxydehydroabietyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole

Three novel 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles were designed,synthesized and characterized by IR,NMR and APCI-MS.3-o-Fluorophenyl-6-（4-decarboxydehydroabietyl）-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole（6a,C28H31FN4S） was structurally determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system,space group P212121 with a=6.0153（14）,b=12.2577（19）,c=34.055（3）A,V=2511.0（7）A^3,Z=4,Mr=474.63,Dc=1.255Mg/m^3,λ=0.71073 A,μ（MoKα）=0.160 mm^-1,F（000）=1008,the final R=0.0555 and wR=0.1248 for 3094 observed reflections with I〉2σ（I）.There are six rings in the crystal structure of the title compound.The dihedral angle between 1,2,4-triazole and 1,3,4-thiadiaole rings is 1.4o,and that between 1,2,4-triazole and benzene ring D 25.5o.

Inhibition effect of 2-amino-5-ethyl-1,3,4-thiadiazole on corrosion behaviour of austenitic stainless steel type 304 in dilute HCl solution

The corrosion inhibition of type 304 austenitic stainless steel by 2-amino-5-ethyl-1, 3, 4-thiadiazole(TTD) compound and the electrochemical behaviour in dilute HCl solution were investigated through potentiodynamic polarization test, mass loss techniques and potential measurements. The results show that the organic derivative is highly effective with a maximum inhibition efficiency of 70.22% from mass loss analysis, while 74.2% is obtained from polarization tests. Observation of the scanning electron micrographs shows the absence of corrosion products due to electrochemical influence of TTD on the surface morphology of the steel. X-ray diffractometry reveals the absence of phase compounds and complexes on the steel samples after exposure. TTD adsorption on the steel surface obeys the Langmuir, Frumkin and Freundlich adsorption isotherms. Corrosion thermodynamic calculations reveal the inhibition mechanism occurs through chemisorption process and results from statistical analysis depict the strong influence of inhibitor concentration on the electrochemical performance of the TTD.

The adsorption of 2,5-dimer-capto-1,3,4-thiadiazole (DMTD) on copper surface and its binding behavior

The interaction mechanism of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) on copper surface was studied by surface-enhanced Raman scattering (SERS), infrared (IR) and X-ray photoelectron spectroscopy (XPS) techniques. The SERS spectra were obtained. We found that DMTD bound with the copper via its two-excocyclic mercapto groups. The monosulphide salt was formed. At the same time, DMTD coordinated with the Cu+ ion through the excocyclic mercapto groups and polymerized via the Cu+ ion into a one-dimensional polymer chain on the copper surface.

血清PCT、CRP及IL-4水平预测小儿支原体肺炎病情严重程度的价值

目的:探讨血清降钙素原(PCT)、C反应蛋白(CRP)及白细胞介素-4(IL-4)水平预测支原体肺炎患儿病情严重程度的价值。方法:选取2019年1月—2023年1月淮安市第二人民医院儿科收治的102例支原体肺炎患儿作为研究对象,根据病情将患儿分为轻症组59例和重症组43例。比较两组临床资料及基质细胞衍生因子(CXCL12)、γ干扰素(IFN-γ)、硫化氢(H_(2)S)、超氧化物歧化酶(SOD)、基质金属蛋白酶-9(MMP-9)、PCT、CRP及IL-4水平,多因素分析采取非条件logistic逐步回归分析,采用ROC曲线分析PCT、CRP及IL-4水平对重症支原体肺炎的预测价值。结果:两组性别、年龄、病程及CXCL12、IFN-γ、H_(2)S、SOD、MMP-9水平比较,差异无统计学意义(P>0.05);重症组PCT、CRP、IL-4水平显著高于轻症组,差异有统计学意义(P<0.05)。logistic逐步回归分析结果显示,PCT、CRP及IL-4为重症支原体肺炎独立危险因素(P<0.05)。ROC分析显示,PCT、CRP及IL-4预测重症支原体肺炎的曲线下面积分别为0.896、0.851、0.787。结论:血清PCT、CRP及IL-4水平均参与支气管肺炎患儿的病情进展,且可作为重症支气管肺炎的诊断指标。

Synthesis, Crystal Structure, and Herbicidal Activities of 2-Cyanoacrylates Containing 1,3,4-Thiadiazole Moieties

Three series of novel 2-cyanoacrylates 7a--7f, 9a-9f, 10a--10f containing 1,3,4-thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II （PS II） electron transportation. Their structures were clearly verified by lH NMR, 13C NMR, elemental analysis （or HRMS analysis） and single-crystal X-ray diffraction analysis. Bioassay showed that a suitable group at the 3-position of acrylates was essential for high herbicidal activ- ity. In particular, compound 7e showed the best herbicidal activities and gave 100% inhibitory activity against rape and amaranth pigweed at a dose of 1.5 kg/ha. Introduction of substituent with higher polarity such as sulfinyl or sulfonyl to the 5-position of 1,3,4-thiadiazole decreased herbicidal activities.

Synthesis and Antitumor Activities of 1,3,4-Thiadiazole Derivatives Possessing Benzisoselenazolone Scaffold

A series of novel 1,3,4-thiadiazole derivatives possessing benzisoselenazolone scaffold were designed and synthesized, and their antitumor activities against human cervix adenocarcinoma（HeLa）, human liver cancer cell（SMMC-7721）, human breast cancer cell（MCF-7） and human lung cancer cell（A549） lines were evaluated by CCK-8 assay, The bioassay results demonstrate that most of the tested compounds showed potent antiproliferative effects against various cell lines. Furthermore, compounds 7c, 7e, 7h, 7i and 7k showed significant antiproliferative activities against SMMC-7721 cells, with IC5o values of 2.38, 2.67, 1.35, 2.75 and 2.48 μmol/L, respectively. Com- pounds 7a, 7e, 7j and 71 exhibited highly effective antitumor activities against MCF-7 cells, with IC50 values of 2.89, 2.95, 1.12 and 2.75 μmol/L, respectively. Compound 7j was found to be the most potent compound against A549 cells, with an IC50 value of 1.25 μmol/L. The pharmacological results suggest that the substituents of benzylthio-moiety at position 2 on 1,3,4-thiadiazole are vital for modulating antitumor activities against various cancer cell lines.