Lewis acid-promoted direct synthesis of N-unsubstituted hydrazones via the reaction of hydrazine with acetophenone and isatin derivatives

Russian Journal of General Chemistry - Hydrazones 2–22 were synthesized via the reaction of acetophenone with isatin derivatives and anhydrous hydrazine promoted by BF3 as a Lewis acid at...     

Electron spin resonance and magnetic studies on some copper(II) azobarbituric and azothiobarbituric acid complexes

Electron spin resonance and magnetic susceptibility on some copper(II) complexes prepared from phenylazobarbituric and phenylazothiobarbituric acid compounds containing 2,5-dichloro and 2,5-dimethyl groups were discussed. The thio complexes exist in dimer-monomer mixture. The corresponding copper(II) complexes of the oxygen homologous failed to exhibit association. Singlet-triplet separation values equal to -321 and -263 cm(-1) for the 2,5-dimethyl and 2,5-dichloro complexes, respectively, of the thio series. An empirical measure of the amount of tetrahedral deformation based on the values of g||/A|| assigned the square-planar geometry of the dimethyl-oxygen complex while the other complexes are with tetrahedral planar geometries. The effect of temperature on the ESR data was discussed. The diamagnetic properties of the complexes derived from 2,5-dichloro and 2,5-dimethyl thiobarbituric acid suggested the formation of Cu(I) complexes.     

Quantitative Tortuosity Measurements of Carbonate Rocks Using Pulsed Field Gradient NMR

Transport in Porous Media - Tortuosity is an important physical characteristic of porous materials; for example, it is a critical parameter determining the effective diffusion coefficient dictating...     

Nanometer-sized,rod-like,ligand-containing tryptophan complexes: Anion influence–structural geometry–antitumor activity correlations

Matrix metalloproteinases (MMPs) are metal-dependent endopeptidases that are related to the initiation and progression of diseases and are involved in physiological processes such as angiogenesis, wound healing, and embryonic development. Synthetic inhibitors of MMPs are amino acid–based ligands as analyzed by the interactions between the enzyme and its natural substrate. Low production cost and low environmental toxicity of α-amino acid complexes resulted in a wide pharmacological spectrum, including the anti-inflammatory and anticonvulsant properties in addition to cytotoxic activities. These facts directed our search for the development of selective inhibitors that contain chemical entity. l -Tryptophan is a main component of proteins and is essential in human nutrition for establishing and sustaining positive nitrogen balance. Nanomaterials exhibited clinical influence in terms of delivery approaches on bioactive molecules as therapeutic and imaging contrast agents. In this article, we report the synthesis of nanometer rod-like 2,2′-(1,3,5,7-tetraoxopyrrolo[3,4-f]isoindole-2,6(1H,3H,5H,7H)-diyl)bis(3-(1H-indol-3-yl)propanoic acid) and its metal complexes. The effect of different anions on the geometrical structures and properties of several complexes was studied. Studies indicated that most complexes exhibited dinuclear octahedral or tetrahedral topologies with M–M interaction being absent, whereas mononuclear square planar or square pyramidal topologies were obtained for copper complexes containing chloride or nitrate anions. The ligand exhibited its activity solely against Bacillus subtilis. [Co₂(L)Cl₂(H₂O)₂] complex exhibited potent activity against various species of pathogenic microorganisms. The cytotoxicity against MCF-7 cell line demonstrated that the inhibitory effect is dose dependent. [Cu(HL)Cl.H₂O] complex exhibited an interesting cytotoxic activity in addition to copper anticancer analogues, the alternatives to cis-platin because of their biocompatibility and important roles in biological systems.