Performance and Limitations of Real-Time Hybrid Simulation with Nonlinear Computational Substructures

Experimental Techniques - Hybrid simulation (HS) and real-time HS (RTHS) are widely used experimental techniques to evaluate the seismic performance of structural components and full systems. The...     

A single-step synthesis of 1,3,4,6-tetraaryl-5-aryliminopiperazin-2-one

Chemical diversity is a strong driver in drug discovery, and chemical reactions that produce multi-substituted heterocycles can result in significant chemical diversity. Here, we report a reaction that leads to highly substituted piperazinone derivatives in a single step. This was discovered accidently while reacting phenylglyoxal and anilines under Povarov conditions. We elucidated the structure of the compound formed when 2-(4-trifluoromethyphenyl)-2-oxoacetaldehyde was reacted with 4-methoxyaniline as (1,4-bis(4-hydroxyphenyl)-5-[(4-hydroxyphenyl)imino]-3,6-diphenylpiperazin-2-one) ( 5e ). The structure was confirmed after extensive spectral analyses, including correlation spectroscopy, nuclear Overhauser effect spectroscopy, heteronuclear single quantum correlation spectroscopy, and heteronuclear multiple-bond correlation nuclear magnetic resonance spectroscopy, in addition to high-resolution mass spectrometry. This reaction is unprecedented and can potentially be exploited as a short route to highly diversified heterocycles.     

Synthesis and reactivity of thieno[2,3-b]quinoline derivatives (Part II)

As a continuation of our previous review entitled “Vilsmeier-Haack cyclisation as a facile synthetic route to thieno[2,3-b]quinolines (Part I).” This review describes the methods of preparation and the chemical reactivity of thieno[2,3-b]quinolines, which might show interesting biological activities.     

Synthesis,spectroscopic properties,density functional theory calculations and nonlinear optical properties of novel complexes of 5‐hydroxy‐4,7‐dimethyl‐6‐(phenylazo)coumarin with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) metal ions

5‐Hydroxy‐4,7‐dimethyl‐6‐(phenylazo)coumarin (L) has been synthesized and its novel complexes with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) metal ions have also been prepared and identified using various analytical tools. The complexes are octahedral binding via one/two oxygen, nitrogen atoms for 1:1 and 1:2 complexes and two/three coordinated water molecules. All the prepared solid complexes behave as neutral in dimethylformamide. The optimized structures of the studied complexes were theoretically investigated at the B3LYP/6‐311G** level. Molecular stability and bond strengths were investigated by applying natural bond orbital analysis. The geometries of the studied complexes are non‐planar as indicated from the values of dihedral angles. The global properties of hardness, global softness and electronegativity were computed. The calculated small energy gap between highest occupied and lowest unoccupied molecular orbital energies shows that charge transfer occurs within the complexes. The obtained total static dipole moment, mean polarizability, anisotropy of polarizability and mean first‐order hyperpolarizability (<β>) were compared with those of urea as a reference material. The results for <β> showed that the complexes are excellent candidates as nonlinear optical materials. The three‐dimensional plots of the molecular electrostatic potential for some selected complexes were investigated.     

Pyrazole and Nicotinonitrile Derivatives Synthesized from Sulfa Drugs,and Their Antibacterial Activity

Russian Journal of General Chemistry - Utility of sulfadiazine and sulfaguanidine in synthesis of new series of pyrazoles and 2-pyridones is described. Diazotization of sulfadiazine that results in...     

Efficient Synthesis and Antimicrobial Evaluation of Acyclic Pyrimidine Nucleosides and Their Sulfanyl Analogs

Russian Journal of Organic Chemistry - A facile synthetic approach has been proposed for a new series of uracil acyclic nucleosides and their sulfanyl analogs via reaction of pyrimidine derivatives...     

Durable fluorescent cotton textile by immobilization of unique tetrahydrothienoisoquinoline derivatives

Cellulose - Due to the sensitivity for interchanging color by exposure to UV light, designing of fluorescent textiles is highly demanded to be employed in camping, military and sensing purposes....     

Threshold switching in V2O5-ZnO-SrO-FeO glasses

Density and current–field characteristics related to switching phenomenon in zinc-doped strontium iron vanadate glasses having the formula (70 ? x)%V₂O₅–x%ZnO–10%SrO–20%FeO, have been investigated over a wide composition range [0 ≤ x ≤ 15] at different thicknesses and temperatures. The samples are found to show threshold switching behavior. The switching fields are found to increase with the increase of zinc content while they decrease when the temperature is increased. The activation energy for switching was found to increase with the increase of ZnO content. Finally, the switching results are discussed in terms of the electrothermal model depending on the samples thicknesses and power calculus.     

Synthesis and Spectroscopic Studies of 3-(3 N-Arylidenehydrazino-1,2,4-triazol-5-yl)-coumarins and Their Biological Activities

The electronic absorption spectra of 3-(3 N-arylidenehydrazino-1,2,4-triazol-5-yl) coumarin III are investigated in organic solvents of varying polarities and buffer solutions of different PH. The behaviour of the latter is utilized in calculating pka values of these compounds. The important bands in the IR spectra and the main ¹H NMR signals are assigned and discussed in relation to molecular structure. The antimicrobial activity of these compound has been investigated.     

Spectrophotometric Studies and Analytical Applications of the Complexes of Fe(III), Ni(II) and Cu(II) with Some 4-Amino-Antipyrene Azo Derivatives

Extensive study of composition, stability constants and optimum conditions of Fe(III), Nl (II) and Cu(II) complexes with four azo compounds based on 4 - amlnoantlpyrene are done. The coloured complexes formed, at the optimum. conditions mentioned, can be successfully used In the mlcrodetermlnation of metal Ions In synthetic solutions as well as In Incoloy 800 alloy. The method described Is rapid, sensitive, highly accurate and reproducable.