Synthesis and plant-growth regulatory activities of novel imine derivatives containing 1H-1,2,4-triazole and thiazole rings

Eleven new imine derivatives 6 containing 1H-1,2,4-triazole and thiazole rings were synthesized by the condensation of 5-((1H- 1,2,4-triazol-1-yl)methyl)-4-tert-butylthiazol-2-amine with various substituted benzaldehydes.The structures of the title compounds were characterized by ~1H NMR,MS and elemental analysis.The plant-growth regulatory activities of these compounds were evaluated.The primary bioassay results indicated that these target compounds exhibited promising plant-growth regulatory activities.

Synthesis, Crystal Structure, Fluorescent Property and DFT Calculations of a New Zn(Ⅱ) Complex Based on 3-(2-Pyridyl)-5-(4-pyridyl)-1H-1,2,4-triazole

A new coordination compound Zn（2,4＇-bpt）2（H2O）（1） based on the versatile ligand 2,4＇-Hbpt（2,4？-Hbpt = 3-（2-pyridyl）-5-（4-pyridyl）-1H-1,2,4-triazole） was prepared by hydrothermal reactions. The structure of complex 1 has been characterized by X-ray single-crystal diffraction, elemental analysis, X-ray powder diffraction, IR spectrum analysis and thermogravimetric analysis. Single-crystal X-ray diffraction analysis indicates that the complex belongs to monoclinic system, space group C2/c with a = 23.877（3）, b = 0.7483（9）, c = 1.2492（2） A, b = 92.681（2）°, V = 2230.6（4） A^3, Z = 4, Dc = 1.572 g/cm^3, m = 1.143 mm^-1, Mr = 527.85 and F（000） = 1080. The final R = 0.0581 and wR = 0.0898 with I 〉 2s（I）. 1 is a 0D motif which is connected by hydrogen bonds to form a corrugated 1D pattern. In addition, 1 shows strong photoluminescent emissions in the solid state at room temperature which can be used as potential optical materials. Theoretical calculations based on density functional theory（DFT） were employed in order to explicate the stability and chemical reactivity of 2,4＇-Hbpt with different conformations. The results indicated that conformation I is more stable and prior to coordination in the reactions.

Two New Metal-organic Frameworks Constructed from 3,4,5-Substituted-1,2,4-Triazole Ligands

Two new complexes,[Zn（L1）2（SCN）2]·H2O（1,L1 = 3,5-dimethyl-4-p-tolyl-4H1,2,4-triazole and [Cd3（L2）6（SCN）6]（2,L2 = 3,5-dimethyl-4-phenyl-4H-1,2,4-triazole）,have been hydrothermally prepared and characterized by single-crystal X-ray diffraction,IR spectroscopy,elemental analysis and PXRD.Complex 1 crystallizes in monoclinic,space group P21 /n with a = 11.246（13）,b = 9.640（11）,c = 26.13（3）,β = 100.97（3）,V = 1108.5（3） 3,Z = 4,C24 H28 N8 OS2 Zn,Mr = 572.02,Dc = 1.366 g/cm3,μ = 1.065 mm-1,S = 0.992,F（000） = 1184,the final R = 0.0602 and wR = 0.1700 for 2925 observed reflections（I 2σ（I））.Complex 2 crystallizes in triclinic,space group P1 with a = 11.6669（3）,b = 12.0957（2）,c = 14.3674（3）,α = 105.380（3）,β = 91.020（2）,γ = 92.4100（10）o,V = 1952.30（7）3,Z = 1,C66H66N24S6Cd3,Mr = 1725.08,Dc = 1.467 g/cm3,μ = 1.025 mm-1,S = 1.037,F（000） = 870,the final R = 0.0336 and wR = 0.0946 for 7819 observed reflections（I 2σ（I））.In the title complexes,complex 1 is a mononuclear molecule where the centre Zn（II） coordinates to two 3,4,5-substituted 1,2,4-triazole ligands（L1） and two terminal SCN-anions in a tetrahedral environment while six-coordinated centre Cd（II） atoms with octahedral geometry in complex 2 are bridged by virtue of substituted 1,2,4-triazole（L2） in N1,N2-bridging mode and μ2-N,N-SCN-anions into a trinuclear molecule.

Syntheses, Structures, and Luminescence Properties of Two New Open-framework Zinc Phosphites Based on 1,2,4-Triazole Derivatives

With 1,2,4-triazole derivatives as structure directing agents, two new openframework zinc phosphites, [Zn（atrz）（HPO3）]n（1） and [Zn（dmatrz）（HPO3）]n（2）（atrz = 4-amino-1,2,4-triazole, dmatrz = 4-amino-3,5-dimethyl-1,2,4-triazole） have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder and single-crystal X-ray diffractions. Both compounds are isostructure and crystallize in the P21/c space group of monoclinic system. Compound 1： a = 9.629（1）, b = 7.384（1）, c = 10.274（1） A, β = 110.729（3）°, V = 683.26（2） A^3, Z = 4, Mr = 229.44, Dc = 2.230 g/cm^3, F（000） = 456, S = 1.10, μ = 3.79 mm^（–1）, R = 0.0181 and w R = 0.0466 for 1121 observed reflections（（40） 〉 2s（（40）））. Compound 2： a = 10.786（2）, b = 8.921（1）, c = 9.749（1） A, β = 107.3°, V = 895.6（3） A^3, Z = 4, Mr = 257.49, Dc = 1.910 g/cm^3, F（000） = 520, S = 1.00, μ = 2.90 mm^（–1）, R = 0.018 and wR = 0.051 for 1581 observed reflections（（40） 〉 2s（（40）））. Both compounds are built up into 4.8-net 2D open-frameworks of vertex-linked Zn O4 and HPO3 units（3.57 × 4.53 A^2 for 1 and 4.43 × 5.90 A^2 for 2）. The structures consist of left-, right-handed helical chains that are connected through oxygen atoms to form an undulated 2D sheet stack, which can be topologically regarded as 4.8~2 nets. Solid-state luminescence properties and thermo gravimetric analyses of these two compounds were investigated, respectively.

Catalytic Kinetic on the Thermal Decomposition of Ammonium Perchlorate with a New Energetic Complex Based on 3,5-Bis(3-pyridyl)-1H-1,2,4-triazole

A new energetic complex,[Co（3,3？-Hbpt）（Htm）]·H_2O（1,3,3？-Hbpt = 3,5-bis（3-pyridyl）-1H-1,2,4-triazole and H_3tm = trimesic acid）,has been synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction,elementary analysis,IR spectroscopy,thermogravimetric analysis and X-ray powder diffraction. Single-crystal X-ray diffraction indicates that the complex belongs to triclinic system,space group P 1 with a = 10.0911（1）,b = 10.2573（1）,c = 10.6393（1） ？,α = 103.793（2）,β = 101.041（2）,γ = 107.918（3）o,V = 974.9（2） ？~3,Z = 2,D_c = 1.732 g·cm-3,μ = 0.941 mm^（-1）,M_r = 508.31,F（000） = 518,the final R = 0.0523 and wR = 0.0935 with I 〉 2σ（I）. In the title complex,Co（Ⅱ） ions are connected by Htm2-anions generating 1D ladder-like chains which are linked by 3,3？-Hbpt to form 1D cages. In addition,the thermal decomposition of ammonium perchlorate（AP） with complex 1 was explored by differential scanning calorimetry（DSC）. AP is completely decomposed in a shorter time in the presence of complex 1,and the decomposition heat of the mixture is 2.531 kJ·g^（-1）,significantly higher than that of pure AP. By Kissinger＇s method,the ratio of Ea/ln（A） is 11.05 for the mixture,which indicates that complex 1 shows good catalytic activity toward the AP decomposition.

Theoretical Studies on Intermolecular Interactions of 4-Amino-5-nitro-1,2,3-triazole Dimers

Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory （DPT） method at the B3LYP/6-311＋＋G＊＊ level. The maximum intermolecular interaction energy is -35.42 kJ/mol via the basis set superposition error-correction （BSSE） and zero point energy-correction （ZPE）. Charge transfers between the two subsystems are small. The vibration analysis of optimized configurations was performed, and the thermodynamic property changes from monomer to dimer have been obtained with the temperature ranging from 200 to 800 K on the basis of statistical thermodynamics. It is found that the hydrogen bonds contribute to the dimers dominantly, and the extent of intermolecular interaction is mainly determined by the hydrogen bonds＇ strength rather than their number. The dimerization processes of Ⅳ, Ⅴand Ⅵ can occur spontaneously at 200 K.

Synthesis and Crystal Structure of Picrates of 3,5-Diamino-1,2,4-triazole

The title compound C2N5H6＋C6N3O7H2-was synthesized by the reaction of 3,5-diamino-1,2,4-triazole and picric acid in the mixture of ethanol and water solution.Single crystals suitable for X-ray measurement were obtained at room temperature.The structure was characterized by elemental analysis and IR and determined by X-ray diffraction analysis.Crystallographic data：C8N8H8O7,Mr = 328.22,monoclinic,space group C2/c with a = 22.815（2）,b = 4.8086（5）,c = 22.564（2）,β = 93.976（2）°,V = 2469.6（4）3,Dc = 1.766 g/cm3,Z = 8,μ = 0.156 mm-1,F（000） = 1344,the final R= 0.0309,wR= 0.0864.

Synthesis and Crystal Structure Analysis of 4-Dibenzaldehydeamino-4H-1,2,4-triazole Diacetate

The new title compound 4-dibenzaldehydeamino-4H-1,2,4-triazole diacetate （C16H18N8O4,Mr = 386.38） has been prepared and its crystal structure was determined by single- crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 8.1371（17）,b = 7.1237（12）,c = 16.325 （2）A,β = 100.366（2）°,V = 930.9（3） A^3,Z = 2,Dc = 1.378,F（000） = 404,μ = 0.104 mm^-1,MoKa radiation （λ = 0.71073 ）,R = 0.0307 and wR = 0.1196 for 4632 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the molecule is not flat and the crystal structure is stabilized mainly by van der Waals interactions.

Synthesis and Crystal Structure of Ag_2(admtrz)_2(CF_3CO_2)_2(admtrz=4-amino-3,5-dimethyl-1,2,4-triazole)

The title compound (Ag2F6O4N8C12H16, Mr = 666.07) was synthesized and its crystal structure was determined by single-crystal X-ray diffraction method. It crystallizes in orthorhombic, space group Fddd with cell parameters: a = 12.2718(1), b = 23.3229(1), c = 29.1918(1) ? V = 8355.10(8) 3, Z = 16, Dc = 2.118 g/cm3, F(000) = 5184 and m = 1.966 mm-1. The structure was solved by direct methods and refined by full-matrix least-squares methods. The final R = 0.0624 and Rw = 0.1699 for 1584 observed reflections with I ≥ 2.0s(I). The molecular structure consists of two trigonal silver atoms bridged by double triazole ligands. The distance between the two silver atoms Ag(1)…Ag(1A) is 3.475(2) ?

Synthesis, Crystal Structure and Biological Activity of 4-Amino-2,4-dihydro-5-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-3H-1,2,4-triazole-3-thione Schiff Base

The target compound 1,2,4-triazole Schiff base containing pyrazole ring was synthesized by 4-amino-2,4-dihydro-5-（（3,5-dimethyl- lH-pyrazol-1-yl）methyl）-3H-1,2,4-triazole-3-thione and 3,4,5-trimethoxy benzaldehyde.The structure was confirmed by IR,~1H NMR,H RMS,elemental analysis and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P1 with a = 7.8772（17）,b = 8.2986（18）,c = 15.392（3） A,α= 93.360（4）,β= 94.609（4）,γ= 93.584（4）°,C（18）H（22）N6O3S,Mr= 402.47,V= 998.9（4） A^3,Z= 2,F（000） = 422,Dc =1.335 g/cm^3,μ= 0.194 mm^（-1）,the final R = 0.0533 and wR = 0.1329 for 3517 observed reflections with I 2σ（I）.The preliminary bioassay results indicate that the target compound has good fungicidal activity against Gibberlla nicotiancola in EC50 value and F.O.f.sp.niveum in EC（95） value.

4-Amino-1,2,4-triazole Resin-supported Palladium Complex as Phosphine-free Catalyst for Suzuki Reaction in Aqueous Phase

1 Introduction The Suzuki cross-coupling reaction is a powerful and versatile method for the generation of unsymmetrical biaryls from arylboronic acids and aryl halides in a single step. However, the reaction is usually performed in the presence of Pd catalyst along with phosphine ligand, which sometimes creates practical problems because organophosphines tend to be expensive, poisonous, and air sensitive. Recently, phos-phine-free ligands,

Synthesis, Structure and Biological Activity of 3-Methyl-4-(3-nitrobenzylideneamino)-5-ethoxycarbonyl-methylsulfanyl-1,2,4-triazole

A Schiff base was synthesized by 3-methyl-4-amino-5-ethoxycarbonyl-methylsul- fanyl-1,2,4-triazole with 3-nitrobenzaldehyde. The structure was confirmed by IH NMR, IR, H RMS, TGA techniques and X-ray diffraction. The crystal belongs to monoclinic system, space group P21/c, with a = 8.965（2）, b = 21.903（5）, c = 9.197（2） ,A, β = 114.011（4）°, CIaH15NsOnS, Mr = 349.08, V= 1649.7（6） A3, De = 1.407 g·cm-3, Z = 4, F（000） = 728,μ =0.226 mm1, the final R = 0.0574 and wR = 0.1336 for 2932 unique reflections with 1 〉 2σ（I）. Furthermore, the biological activity to four vegetable pathogens has been tested. The title compound exhibits better biological activity to four vegetable pathogens compared to the Schiff base without 5-ethoxycarbonyl and to Gibberlla saubinetti in EC95 compared with triadimefon.

Synthesis and Properties of Double Calix[4]arene Derivatives Linked by Schiff-base in the Lower Rim

25,27-bis-(2-aminoethoxy)-p-tert-butylcalix[4]arene was linked to double calix[4]arene derivatives by the Schiff-base moiety in its lower rim. They behave strong ability to complex with Ph2+, Cu2+ and Co2+.

Synthesis and Biological Activity Study of New Schiff and Mannich Base Ligands Derived from Isatin and 3-Amino-1,2,4-triazole and Their Metal Complexes

Two new Mannich and Schiff base ligands namely： （1-（3＇-amino-methyl-1＇（H）-1＇,2＇,4＇-triazole）-3-（1＇（H）-l＇,2＇,4＇- triazole-3＇-yl） iminoisatin （Lt） and l-morpholinomethyl-3-（1＇（H）-1＇,2＇,4＇-triazolyl）iminoisatin （LII） were prepared from condensation reaction of the new Schiff base 3-（l＇（H）-l＇,2＇,4＇-triazole-3＇-yl）iminoisatin （SBH） （0.01 mol） with formaldehyde and 3-amino-l,2,4-triazole （3-At） or with formaldehyde and morpholine （0.01 mole each） respectively. Structures were characterized by tH NMR, CHN analyses, mass spectra and IR spectra. Metal complexes were synthesized by heating each ligand （0.02 mo with metal salts （0.01 moo in ethanol or ethanol： acetone mixture respectively. The formula of metal complexes were suggested depending on CHN and thermal analyses, metal and chloride contents, IR and UV-visible spectra, magnetic moments （laefr） and conductivity measurements. All complexes were of octahedral geometry except palladium （II） complexes which were square planar. The two ligands and some selected metal complexes showed various antibacterial and cytotoxic effects.

Solid Phase Synthesis of 3,4,5-Trisubstituted-1,2,4-Triazoles Derivatives from the Resin-Bound Acylhydrazines

An extension of our methodology on solid-phase synthesis of 3,4,5-trisubstituted-1,2,4-triazoles under mild conditions has been developed. Firstly, the resin-bound acylhydrazine is reacted with orthoesters to provide resin-bound 1,3,4-oxadiazoles. Secondly, condensation of 1,3,4-oxadiazoles resin with the corresponding arylamines hydrochloride to form the the resin-bound triazoles. 3,4,5-Trisubstituted-1,2,4-triazoles derivatives were obtained from resin-bound acylhydrazines in several steps providing 78% - 87% overall yields and excellent purity. The advantages of this method include straightforward operation and high yield and purity of the products.

Thermodynamic Study and Spectroscopic Analysis of a Charge-Transfer Complex between 3,5-Diamino-1,2,4-Triazole and 6-Methyl-1,3,5-Triazine-2,4-Diamine with Chloranilic Acid

Studying of charge-transfer (CT) and proton transfer interactions is essential due to their important role in many biological field and industrial applications. The current work will add more information’s about the nature of interaction between 3,5-diamino-1,2,4-triazole (DAT) and 6-methyl-1,3,5-triazine-2,4-diamine (MTDA) with 3,6-dichloro-2,5-dihydroxy-p-benzoquinone (chloranilic acid CLA) which was studied spectrophotometrically in Ethanol (EtOH) and Methanol (MeOH) solvents at different temperatures. The molecular composition of the formed complexes was studied by applying continuous variation and spectrophotometric titration methods and found to be 1:1 charge transfer complex for both Complex (DAT:CLA) and (MTDA:CLA) which are produced. Minimum-Maximum absorbance’s method has been applied to calculate the formation constant KCT and molecular extinction coefficient (ε);they recorded high values confirming high stability of the produced complexes. Oscillator strength (f), transition dipole moment (μ), ionization potential (IP) and dissociation energy (W) of the formed CT-complexes were also determined and evaluated;they showed solvent dependency. It is concluded that the formation constant (KCT) of the complexes is found to depend on the nature of both electron acceptor and donors and on the polarity of solvents.

Theoretical Study on the Mechanism of a New Synthesis Reaction of 1,3,5-Substituted-1,2,4-triazoles by Carboxylic Acids,Amidines,and Hydrazines

The synthesis of 1,3,5-substituted-1,2,4-triazoles from α-imino-3-pyridine formic acid,acetamidine and anisole hydrazine as a model reaction in this paper and the synthesis mechanism of 1,3,5-substituted-1,2,4-triazole compounds from carboxylic acids,amidines and hydrazines have been first investigated with the B3 LYP/6-311＋＋G＊＊ method.According to the potential energy profile,it can be predicted that the course of the reaction consists of five reactions containing six elementary reactions.The α-imino-3-pyridine formic acid and acetamidine form first an intermediate product through a dehydration reaction; the intermediate product further combines with hydrogen ion to form a positive ion; the positive ion reacts with anisole hydrazine by a dehydration reaction to form another positive ion; then,followed by two isomerization reactions,the final reaction with the acetate ion（Ac-） produces the final product.The research results reveal the laws of synthesis reaction of 1,3,5-substituted-1,2,4-triazoles by the carboxylic acids,amidines,hydrazines and their derivatives on theoretical level.It provides the systemic theoretical basis for the synthesis,development and application of 1,3,5-substituted-1,2,4-triazole compounds.

Aromatic Multicarboxylate Ligands Tuned One-and Three-dimensional Zn(Ⅱ) Coordination Polymers Based on 3-(1H-pyrazol-4-yl)-5-(pyridin-3-yl)-1,2,4-triazole

Two aromatic multicarboxylate ligands tuned Zn(Ⅱ) coordination polymers, namely, {[Zn0.5(H2L)(tp)0.5(H2O)]H2O}n(1) and {[Zn2(HL)(btc)(H2O)]H2O}n(2)(H2L = 3-(1 Hpyrazol-4-yl)-5-(pyridin-3-yl)-1,2,4-triazole, H2tp = terephthalic acid;H3 btc = 1,3,5-benzenetricarboxylic) have been synthesized. Their structures were characterized by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional chain structure and is finally extended into a three-dimensional supramolecular architecture though hydrogen bonding interactions. Compound 2 shows a three-dimensional framework. Meanwhile, compounds 1 and 2 exhibit luminescent emission in the solid, and can be investigated as potential luminescent materials.

Design,synthesis,and biological evaluation of 1,2,4-triazole derivatives as potent antitubercular agents

Inhibition of mycobacterial membrane protein large 3(MmpL3)thereby affecting the mycolic acid biosynthetic pathway has been proven to be an effective strategy for developing antitubercular drugs.Based on the X-ray crystal structure of MmpL3 inhibitor complexes,a series of novel 1,2,4-triazole derivatives were designed,synthesized and evaluated antitubercular activity against Mtb strain H37Rv.Comprehensive structure–activity relationship exploration resulted in the identification of compounds 21 and 28,which possess potent antitubercular activity against Mtb strain H37Rv[minimum inhibitory concentration(MIC)=0.03–0.13μg/mL]and the clinical isolates of multidrug resistance(MDR)and extensive drug resistance(XDR)tuberculosis(MIC=0.06–1.0μg/mL).Moreover,compounds 21 and 28 showed neglectable cytotoxicity(IC_(50)≥32μg/mL)to the mammalian Vero cells and favorable physicochemical and pharmacokinetic properties according to the in silico absorption,distribution,metabolism and excretion(ADME)prediction.Finally,the potential target of representative 1,2,4-triazole 28 was identified to be MmpL3 using a microscale thermophoresis(MST)assay.

Synthesis,Crystal Structure,DFT Studies and Antifungal Activity of 5-(4-Cyclopropyl-5-((3-fluorobenzyl)sulfonyl)-4H-1,2,4-triazol-3-yl)-4-methyl-1,2,3-thiadiazole

5-（4-Cyclopropyl-5-（（3-fluorobenzyl）sulfonyl）-4H-1,2,4-triazol-3-yl）-4-methyl-1,2,3-thiadiazole was synthesized and recrystallized from Et OH. The compound was characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction. The structure-active relationship and the antifungal activity based on density functional theory calculation（DFT） and antifungal activities were investigated. The compound crystallizes in the monoclinic space group P121/n1 with a = 8.929（3）,b=12.715（4）,c=15.161（5） A°,β = 106.142（3）o,V = 1653.3（9） A°3,Z = 4 and R = 0.0393 for 3930 observed reflections with I 〉 2σ（I）. Theoretical calculation of the title compound was carried out with B3LYP/6-31G（d,p）. The full geometry optimization was carried out using the 6-31G（d,p） basis set.The frontier orbital energy and atomic net charges were discussed. The observed results of the compound have been compared with theoretical results and the experimental data show good agreement with the calculated values. The compound exhibits good antifungal activity.