Synthesis,characterization and crystal structure of new silver(I) and palladium(II) complexes containing 1,2,4-triazole moieties

The reaction of 4-amino-5-ethyl-2H-1,2,4-triazole-3(4H)-thione (AETT, L1) with 2-thiophen carbaldehyde in methanol leads to the corresponding Schiff-base HL1a. The reaction of L1 with AgNO₃ in ethanol gives the ionic complex [{[Ag(L1)]NO₃}₂]_n (1). The ionic complex [(PPh₃)₂Ag(HL1a)₂]NO₃ · CH₃CN (2) can be obtained by the reaction of HL1a with [(PPh₃)₂Ag]NO₃ in methanol and acetonitrile solution, while its reaction with [(PPh₃)₂PdCl₂] in the presence of sodium acetate in methanol leads to the neutral complex [(PPh₃)₂Pd(L1a)₂] · 4MeOH (3). All the compounds were characterized by infrared spectroscopy, elemental analyses as well as by X-ray diffraction studies.     

Synthesis and fungicidal activity of novel 1,2,4-triazole derivatives containing a pyrimidine moiety

Abstract

A series of novel 1,2,4-triazole derivatives containing a pyrimidine moiety were synthesized and their fungicidal activities were evaluated. The preliminary biological test indicated that some of the target compounds exhibited moderate to good fungicidal activities against the tested plant pathogenic fungi compared with the commercial agent. Among them, compounds 9n and 9o exhibited excellent antifungal activity against Phompsis sp., with the half-maximal effective concentration (EC₅₀) values of 25.4 and 31.6?μg/mL, which were even better than the commercial agent of Pyrimethanil (32.1?μg/mL). Meanwhile, compound 9o showed better fungicidal activities against B. dothidea and B. cinerea with 40.1 and 55.1?μg/mL, respectively, in comparison with that of commercial Pyrimethanil (57.6 and 62.8?μg/mL).     

Synthesis and biological activities of new 1H-1,2,4-triazole derivatives containing ferrocenyl moiety

Some new 1H-1,2,4-triazole derivatives containing ferrocenyl moiety were synthesized in various yields by the condensation of ferrocenecarboxaldehyde with 1-(1H-1,2,4-triazol-1-yl)-3-aryl-2-one in toluene. Their structures of all these new compounds have been confirmed with ¹H NMR, IR, MS and elemental analysis. Their results of bioassay showed that some title compounds exhibited some degree of antifungal and plant growth regulatory activities.     

Synthesis and molecular structure of cobalt(II) complex with 1-(1-silatranylmethyl)-1,2,4-triazole

Reaction of cobalt chloride with 1-(1-silatranylmethyl)-1,2,4-triazole in benzene afforded complex CoCl₂·2L (L = 1-(1-silatranylmethyl)-1,2,4-triazole). It was isolated as the solvate [CoCl₂·2L]·CH₂Cl₂ (1) by recrystallization from dichloromethane and structurally characterized by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2₁/m with a = 6.798(2) E, b = 20.326(5) E, c = 11.005(3) E, and Z = 4. The cobalt atom is in slightly distorted square-planar environment, coordinated to two nitrogen atoms from two ligands and two chloride ions.     

Synthesis and antifungal activity of novel 1,2,4-triazole derivatives containing an amide moiety

A series of novel 1,2,4-triazol derivatives containing an amide moiety were synthesized and their antifungal activities were evaluated. The results indicated that some of the target compounds possessed good antifungal activities. Among them, compounds 6a , 6g , 6k , and 6m showed excellent antifungal activities against Botrytis cinerea, with an inhibition rate of 91.8%, 90.1%, 93.6%, and 91.2% at a concentration of 50 μg/mL, which were superior to that of Pyrimethanil (82.8%). Meanwhile, compound 6b showed better antifungal activity against Phompsis sp, with an inhibition rate of 92.4%, in comparison with that of Pyrimethanil (85.1%).     

Synthesis, structure and characterization of binuclear silver(I) complexes

Summary Two binuclear Ag^I complexes, [{Ag(dppp)}₂](NO₃)₂ (1) and [{Ag(dppb)}₂(NO₃)]₂ (2) (dppp = Ph₂P(CH₂)₃PPh₂, dppb = Ph₂P(CH₂)₄PPh₂], were synthesized and characterized by elemental analysis, t.g., i.r. and ³¹P-n.m.r. spectra. Single crystals of complex (2) were obtained from MeOH-CHCl₃. The X-ray crystal structure shows that the dppb ligand is bidentate, with two ligands bridging two metal ions to form a centrosymmetric dimer.     

Synthesis and structure of new ditopic ligands containing tetrazole and 3-nitro-1,2,4-triazole fragments

Alkylation of 3-nitro-1,2,4-triazole with haloalkyltetrazoles has afforded in high yields previously unknown 1-[2-(3-nitro-1H-1,2,4-triazol-1-yl)ethyl]-1H-tetrazole and 2-tert-butyl-5-(3-nitro-1H-1,2,4-triazol-1-ylmethyl)-2H-tetrazole. The molecular and crystal structure of these compounds has been established by X-ray diffraction analysis (XRD).     

Synthesis, characterization, and molecular structure of Ru(II) complex containing 2,5-pyridinedicarboxylic acid

This article presents a combined experimental and computational study of Ru(II) complex containing 2,5-pyridinedicarboxylic acid ligand. The novel complex [Ru(py-2,5-COOH)₂(PPh₃)₂]·3H₂O has been obtained in the reaction of [RuCl₂(PPh₃)₃] with 2,5-pyridinedicarboxylic acid in methanol and has been studied by IR, ¹H, ³¹P NMR, UV–Vis spectroscopy, and X-ray crystallography. The electronic structure of [Ru(py-2,5-COOH)₂(PPh₃)₂] has been calculated with the density functional theory (DFT) method. The spin-allowed electronic transitions of the complex have been calculated with the time-dependent DFT method, and the UV–Vis spectrum has been discussed on this basis and rationalized by determination of ligand field splitting (10Dq) and Racah’s parameters from the experimental spectrum. The luminescence property of the complex has been examined.     

Synthesis and molecular structure of the first rhodium(I) complex containing a tetra-tert-butylcyclopentaphosphanide ligand

Na[cyclo-(P(5)(t)Bu(4))] (1) reacts with [RhCl(PPh(3))(3)] (1:1) to give the first rhodium(I) complex with a tetra-tert-butylcyclopentaphosphanide ligand, [Rh{cyclo-(P(5)(t)Bu(4))}(PPh(3))(2)] (2). 2 was characterized by NMR ((1)H, (13)C, (31)P), MS, IR, and X-ray structure determination.     

Synthesis, characterization and photophysics of fluorene-alt-oxadiazole copolymers containing pendent iridium (III) complex moiety

A series of fluorene-alt-oxadiazole copolymers containing a pendent phosphor chromophore of the (piq)₂Ir(pic) complex were synthesized via the palladium-catalyzed Suzuki coupling reaction, where piq is 1-phenylisoquinoline and pic is picolinic acid. These copolymers exhibited a similar absorption spectrum with a peak at about 330 nm and a typical emission peak at 408 nm in CH₂Cl₂ from the fluorene-alt-oxadiazole backbone. However, a significantly red-shifted emission peak at about 625 nm was observed in the neat films of these copolymers, which are attributed to the pendent iridium (III) complex unit. Using these copolymers as single emission layer, the polymer light-emitting devices with a configuration of ITO/PEDOT:PSS/copolymers/LiF/Al exhibited a saturated red emission with a peak at 632 nm. Significant influence of the attached iridium (III) complex ratio on EL performance was presented. A maximum current efficiency of 1.2 cd/A at 63 mA/cm² and a maximum luminance of 1125 cd/m² at 12 V were achieved from the device with the copolymer containing iridium (III) complex in a 3% molar ratio.     

Synthesis and characterization of two zinc(II) macrocyclic Schiff-base complexes containing piperazine moiety, crystal structure of one complex

Two symmetrical and asymmetrical Zn(II) complexes of a pentadentate (N₅) macrocyclic Schiff-base ligands, were prepared via templated [1 + 1] cyclocondensation of 2,6-diacetylpyridine with two different amines containing piperazine moiety. The complexes have been characterized by a variety of methods including, IR, FAB mass spectrometry, elemental analysis and conductivity measurements. The crystal structure of the asymmetric complex, [ZnL¹Br]ClO₄ was determined by X-ray diffraction. It is shown that in the solid state the complex adopts a distorted pentagonal–pyramidal geometry, with the macrocycle in the pentagonal plane and the bromide ion in the axial position.     

Synthesis and antimicrobial activity of some new 1,3,4-thiadiazole and 1,2,4-triazole compounds having a D,L-methionine moiety

New 1,3,4-thiadiazole, 5a-e, and 1,2,4-triazolecompounds 6a-c, containing a D,L-methionine moiety were synthesized by intramolecular cyclization of 1,4-disubstituted thiosemicarbazides 4a-e in acid and alkaline media, respectively. The potential antimicrobial effects of the synthesized compounds were investigated using the Staphylococcus aureus ATCC 25923, Bacillus antracis ATCC 8705, Bacillus cereus ATCC 10987, Sarcina lutea ATCC 9341 and Escherichia coli ATCC 25922 strains. The newly synthesized compounds exhibited promising activities against Bacillus antracis and Bacillus cereus.     

Synthesis and crystal structure of a silver(I) 6-methylmercaptopurine riboside complex

Silver nitrate reacts with 6-methylmercaptopurine riboside (6-MMPR) in aqueous solution containing methanol and dimethyl sulfoxide at room temperature to give a colourless crystalline complex, namely, bis(6-methylmercaptopurine riboside-κN⁷)(nitrato-κ²O,O′)silver(I) 2.32-hydrate, [Ag(NO₃)(C₁₁H₁₄N₄O₄S)₂]·2.32H₂O. The crystal structure, determined from synchrotron diffraction data, shows a central Ag^I ion on a crystallographic twofold rotation axis, coordinated in an almost linear fashion by two 6-MMPR ligands via atom N7 (purine numbering), with the nitrate counter-ion loosely coordinated as a bidentate ligand, forming a discrete molecular complex as an approximate dihydrate. The complex and water molecules are connected in a three-dimensional network by hydrogen bonding.     

Synthesis,crystal structure and properties of a silver(I) complex with 2-(1H-1,2,4-triazol-1-yl) acetic acid

The treatment of 2-(1H-1,2,4-triazol-1-yl) acetic acid (Htza) with AgClO₄ resulted in [Ag₃(tza)₂(ClO₄)] _n . Its crystal structure was characterized by X-ray crystallography. Each pair of adjacent Ag1 atoms, separated at 2.954 Å, is bridged by the bidentate carboxylate. Each Ag2 is coordinated in an exactly linear geometry by two triazole nitrogens from two tza^? ligands. Solid state fluorescent measurements have a ligand-based emission at 415 nm. Thermal properties were also investigated.     

Synthesis and characterization of silver polymer nanocomposites of 1-vinyl-1,2,4-triazole with acrylonitrile

Novel organic-inorganic nanocomposites were synthesized by chemical reduction of silver ions from silver acetate in DMSO and DMF solutions in the presence of the stabilizing copolymer of 1-vinyl-1,2,4-triazole-acrylonitrile. The solvents DMSO and DMF can act as efficient reducing agents for silver ions, which makes it possible to carry out the reaction under mild conditions and simplify procedures of nanocomposite isolation. The structure and properties of the starting copolymer and related nanocomposites were characterized by UV, IR, and ¹H and ¹³C NMR spectroscopy, as well as transmission electron microscopy and thermogravimetry. The prepared polymer nanocomposites contain 6.8–7.2% silver in the form of nanoparticles with a size of 2–20 nm uniformly dispersed in the polymer matrix. The nanocomposites are readily soluble in DMSO and DMF and do not decompose on heating to 260 °C.     

Synthesis,structure and characterization of copper(II) and zinc(II) complexes based on 3-carboxyl-1,2,4-triazole

Two complexes [CuL₂(H₂O)₂] (1) and [ZnL₂(H₂O)₂] (2) (L?=?3-carboxyl-1,2,4-triazole (L)) have been synthesized and characterized by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in the monoclinic space group P ₂(1)/n, a?=?8.632(8)?Å, b?=?9.153(8)?Å, c?=?6.991(7)?Å, β?=?94.279(12)°, Z?=?2, R ₁?=?0.0296, wR ₂?=?0.0918. Compound 2 also crystallizes in the monoclinic space group P ₂(1)/n, a?=?4.937(3)?Å, b?=?18.107(10)?Å, c?=?6.344(4)?Å, β?=?106.839(7)°, Z?=?2, R ₁?=?0.0230, wR ₂?=?0.0556. Extensive intermolecular hydrogen bonds assemble 1 and 2 into three-dimensional (3D) supramolecular architectures, with eight-member H-bonded synthons. Compounds 1 and 2 were also characterized by element analysis, FT–IR, luminescence and EPR studies.