Synthesis, Characterization, Thermal Decomposition Mechanism and Non-Isothermal Kinetics of the Pyruvic Acid-Salicylhydrazone and Its Complex of Praseodymium(III)

IntroductionHydrazonesactasherbicides,insecticides,nemato cides ,rodenticidesandplantgrowthregulators.Theyshowspasmolyticactivity ,hypotensiveactionandactivityagainstleukaemia,sarcomasandothermalignantneoplasm .1Rareearthelementshavestrongbiologicaleffectandmanycom plexesofrareearthshaveallkindofmedicinalactivities.2 Aseriesof 2 oxopropionyl(pyridine 4 fomyl)hydrazonewithrareearthscomplexeswassynthesizedbyYangandtheEucom plexshowedacertainanticanceractivity .3Therearethreeradicalsinthepyru…     

Readily accessible rhodamine B-based photoresponsive material

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Synthesis of 3-(3-Methyl-1-aryl-1H-pyrazol-5-yl)-2H-2-chromen-2-one Derivatives via a One-Pot,Three-Component Reaction

An efficient synthesis of 3-(3-methyl-1-aryl-1H-pyrazol-5-yl)-2H-2-chromen-2-one derivatives by the reaction of salicylaldehydes, 4-hydroxy-6-methyl-2H-pyran-2-one, and arylhydrazine in acetonitrile under reflux condition and in the presence of piperidine is reported. This three-component reaction has some advantages such as ease of handling, good yields, and easy purification. All structures were confirmed by infrared, mass, ¹H NMR, and ¹³C NMR spectroscopy.     

An efficient ZnO-catalyzed synthesis of novel indole-annulated thiopyrano-chromene derivatives via Domino Knoevenagel-hetero-Diels-Alder reaction

An efficient synthesis of pentacyclic indole derivatives is achieved via domino Knoevenagel-hetero-Diels-Alder reactions of indolin-2-thiones and O-propargylated salicylaldehyde derivatives in CH₃CN in the presence of 10 mol % of ZnO as a heterogeneous catalyst. The products are formed in good to excellent yields.     

A new domino Knoevenagel-hetero-Diels-Alder reaction: an efficient catalyst-free synthesis of novel thiochromone-annulated thiopyranocoumarin derivatives in aqueous medium

An efficient catalyst-free synthesis of novel pentacyclic thiochromone-annulated thiopyranocoumarin derivatives is achieved via domino Knoevenagel-hetero-Diels-Alder reaction of 4-hydroxy dithiocoumarin and O-acrylated salicylaldehyde derivatives in H₂O as solvent. The products are formed in good yields with high regio- and stereo-selectivity.     

Acid-base titrations of schiff bases in deuteriomethanol as studied by1H NMR

The Schiff bases of salicylaldehyde and pyridoxal 5-phosphate with amino compounds were studied by¹H NMR in CD₃OD by using a glass electrode for the control of acidity. This study makes a new contribution for the elucidation of the structures of pyridoxylidene Schiff bases and gives additional data on the¹H NMR of the compounds that have not been available from the related studies in aqueous solutions.     

Schiff碱配合物Cd(H2SalN)2(OAc)2(H2O)]·3(H2O)的合成与结构

用一步法合成了一个Schiff碱配合物[Cd(H2SalN)2(OAc)2(H2O)]·3(H2O)(H2SalN=salicylaldehyde isonicotinoylhydrazone),并用IR和X射线单晶衍射进行了结构测定.该化合物属于三斜晶系,P-1空间群,晶胞参数为:a =1.554 4(3) nm,b...     

Synthesis,structural studies and bio-activity of some metal(II) complexes with glyoxal salicylaldehyde acyldihydrazones

Complexes of the type [M(gssdh)]Cl and [M(gspdh)]Cl, where M?=?Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), Hgssdh?=?glyoxal salicylaldehyde succinic acid dihydrazone and Hgspdh?=?glyoxal salicylaldehyde phthalic acid dihydrazone, have been synthesized and characterized by elemental analyses, molar conductance, magnetic moments, electronic, ESR and IR spectra and X-ray powder diffraction studies. The metal complexes are insoluble in common organic solvents and are 1?:?1 electrolytes. The magnetic moment values and electronic spectra indicate a spin–free octahedral geometry for all Co(II), Ni(II) and Cu(II) complexes. ESR spectral parameters of Cu(II) complexes suggest an elongated tetragonally–distorted octahedral stereochemistry around copper. Both ligands are monobasic hexadentate ligands coordinating through three >C=O, two >C=N– and a deprotonated phenolate group to the metal. X-ray powder diffraction parameters for three of the complexes correspond to an orthorhombic crystal lattice. The complexes show appreciable activity against various fungi and bacteria.     

Reactions of chromium and molybdenum carbonyls with bis-(salicylaldehyde)-1,3-propylenediimine Schiff base

Interaction of a Schiff base, bis-(salicylaldehyde)-1,3-propylenediimine, salpenH₂, with M(CO)₆ (M?=?Cr or Mo) in the presence of oxygen gave the oxo-complexes[M(O)(salpen)]. Magnetic studies for the two oxo-complexes showed chromium and molybdenum in the +4 formal oxidation state. In presence of pyridine, reaction of Cr(CO)₆ with salpenH₂ gave the identical product; [Cr(O)(salpen)]. Reaction of Mo(CO)₆ with salpenH₂ in presence of pyridine (py) resulted in formation of the square-pyramidal complex [Mo(py)(salpenH₂)]. Reactions of M(CO)₆ with salpenH₂ in presence of a ligand L (L?=?bipyridine (bpy) or 3,3-dimethylbipyridine (dmbpy)) gave the octahedral complexes [M(L)(salpenH₂)]. All the complexes were characterized by elemental analyses, IR, mass and ¹H NMR spectroscopy. The spectroscopic studies revealed the proposed structures. UV-Vis spectra of the ligand and its complexes in DMSO exhibited visible bands due to metal-to-ligand or ligand-to-metal charge transfer.