Synthesis and characterization of new dioxomolybdenum(VI) complexes of ONS donor Schiff bases derived from thiosemicarbazide,S-methyldithiocarbazate,S-benzyldithiocarbazate ando-hydroxy-aromatic aldehydes/ketones

Summary Syntheses of several new dioxomolybdenum(VI) complexes with composition MoO₂L · MeOH (where LH₂ = Schiff base derived from salicylaldehyde, 2-hydroxy-1-naphthaldehyde,o-hydroxyacetophenone,o-hydroxybenzophenone, pyridoxal and thiosemicarbazide,S-methyldithiocarbazate orS-benzyldithiocarbazate) are reported. The complexes have been characterized by elemental analysis, i.r., n.m.r. and electronic spectra, conductance, molecular weight and magnetic susceptibility measurements. The complexes are monomers, nonelectrolytes, diamagnetic and six-coordinated. The Schiff bases behave as dibasic tridentate ligands and coordinate through phenolic oxygen, thioenolic sulphur and azomethine nitrogen atoms. The complexes have acis-O=Mo=O structure as evidenced by the presence of two strong bands at 880–915 and 925–955 cm^–1. All of the complexes exhibit a band atca. 25000 cm^–1 due to the ligand to metal charge transfer transition.     

Quantum Discord and Entanglement of Quasi-Werner States Based on Bipartite Entangled Coherent States

Present work is an attempt to compare quantum discord and quantum entanglement of quasi-Werner states formed with the four bipartite entangled coherent states (ECS) used recently for quantum teleportation of a qubit encoded in superposed coherent state. Out of these, the quasi-Werner states based on maximally ECS due to its invariant nature under local operation is independent of measurement basis and mean photon numbers, while for quasi-Werner states based on non-maximally ECS, it depends upon measurement basis as well as on mean photon number. However, for large mean photon numbers since non-maximally ECS becomes almost maximally entangled therefore dependence of quantum discord for non-maximally ECS based quasi-Werner states on the measurement basis disappears.     

Electrophoresis of soft particles with hydrophobic inner core grafted with pH-regulated and highly charged polyelectrolyte layer

Electrophoresis of core–shell composite soft particles possessing hydrophobic inner core grafted with highly charged polyelectrolyte layer (PEL) has been studied analytically. The PEL bears pH-dependent charge properties due to the presence of zwitterionic functional groups. The dielectric permittivity of the PEL and bulk aqueous medium were taken to be different, which resulted in the ion-partitioning effect. Objective of this study was to provide a simple expression for the mobility of such core–shell soft particles under Donnan limit where the thickness of the PEL well exceeds the electric double layer thickness. Going beyond the widely used Debye–Hückel linearization, the nonlinear Poisson–Boltzmann equation coupled with Stokes–Darcy–Brinkman equations was solved to determine the electrophoretic mobility. The derived expression further recovers all the existing results for the electrophoretic mobility under various simplified cases. The graphical presentation of the results illustrated the impact of pertinent parameters on the electrophoretic mobility of such a soft particle.     

Thermal,mechanical and water barrier properties of graphene oxide/polyvinyl alcohol/polyol composite films

The novel polymer composite of polyvinyl alcohol (PVA), polyol(PO) and graphene oxide (GO) was used to prepare the PVA/PO and GO/PVA/PO with different weight percents of GO (0.5 and 1% denoted as (0.5 wt%)GO/PVA/PO and (1 wt%)GO/PVA/PO, respectively) through solution casting blend technique. The structure–properties of all used films were confirmed by scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and mechanical properties. The SEM results exhibited the uniform and homogeneous dispersion of GO in the PVA/PO blend matrix. The TEM and XRD analysis confirmed the structure and exfoliation of GO nanosheets, respectively. Thermal stability suggested that (0.5 wt%)GO/PVA/PO and (1 wt%) GO/PVA/PO films are more stable than PVA/PO. The tensile strength of (0.5 wt%)GO/PVA/PO and (1 wt%)GO/PVA/PO films reached 270.5% and 1349.6%, respectively, which are higher than that of the PVA/PO film. The decrease in the water absorption (WA) of GO/PVA/PO was found from 110.5 to 38.4%. The physico-mechanical properties of used films suggested that the prepared GO/PVA/PO blend composite films can be applied in food packaging areas.     

Influence of Coordination Geometry on the Ring Opening of Benzoxazine: Oxidovanadium(V), Dioxidomolybdenum(VI) and Dioxidotungsten(VI) Complexes of Benzoxazine Based Ligands and their Bio Inspired Catalytic Applications

Mono benzoxazine appended N-capped amino bis(disubstitutedphenol) ligands [ II ( a–c )] upon reaction with V^VO(OEt)₃ in a 1 : 1 molar ratio in EtOH/MeOH give [{V^VO}en(3,5-dtbb)₃] ( 1 ), [{V^VO}en(3-tb,5-mb)₃] ( 2 ) and [{V^VO}en(3,5-dmb)₃] ( 3 ). During the reaction, the benzoxazine ring opens with the loss of methylene group and the newly formed ligands, N,N-bis(2-hydroxy-3,5-disubstitutedbenzyl)-N’-2-hydroxy-3,5-disubstituted benzyledene-1,2-diaminoethane [ III ( a–c )], behave as tribasic pentadentate in these complexes. Under similar conditions, when [M^VIO₂(acac)₂] (M=Mo or W; Hacac=acetylacetone) reacts with II ( a–c ), these ligands retain their identity and form cis-[M^VIO₂] complexes, [{Mo^VIO₂}{en(3,5-dtbb)₂(6,8-dtbbenzox)}] ( 4 ), [{Mo^VIO₂}{en(3-tb,5-mb)₂(6-tb,8-mbbenzox)}] ( 5 ) and [{Mo^VIO₂}{en(3,5-dmb)₂(6,8-dmbenzox)}] ( 6 ), [{W^VIO₂}{en(3,5-dtbb)₂(6,8-dtbbenzox)}] ( 7 ), and [{W^VIO₂}{en(3-tb,5-mb)₂(6-tb,8-mbbenzox)}] ( 8 ). However, the benzoxazine ring ruptures in case of ligand IIc under these conditions and form [{W^VIO₂}{en(3,5-dmb)₃}] ( 10 ), similar to complexes 1–3 . Complex [{W^VIO₂}{en(3,5-dmb)₂(6,8-dmbenzox)}] ( 9 ), having structure similar to 4–8 , could only be obtained when the reaction was carried out in toluene. Not only 9 , even complexes 4–8 can be isolated in toluene. Rupturing of both benzoxazine rings has also been experienced when ligands 1,2-bis(6,8-disubstitutedbenzo[e][1,3]oxazin-3(4H)-yl)ethane [ I ( a–c )] react with [M^VIO₂(acac)₂] (M=Mo or W) in MeOH and give salan type complexes [(M^VIO₂)en(3,5-dtbb)₂] [M=Mo ( 11 ), M=W ( 14 )], [(M^VIO₂)en(3-tb,5-mb)₄] [M=Mo ( 12 ), M=W ( 15 )] and [(M^VIO₂)en(3,5-dmb)₄] [M=Mo ( 13 ), M=W ( 16 )]. Complexes 1–9 have been used as catalyst for the multicomponent Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) and oxidative bromination of phenol derivatives.     

Catalytic Potential of Pyrazolone Based Dioxidomolybdenum(VI) Complexes for Multicomponent Biginelli Reactions,Epoxidation of Olefins and Oxidative Bromination of Phenol Derivatives

Three different types of dioxidomolybdenum(VI) complexes of 4-acetyl-3-methyl-1-phenyl-5-pyrazolone (Hmp, I )), 3-methyl-1-phenyl-4-propionyl-5-pyrazolone (Hpp, II ), 4-butyryl-3-methyl-1-phenyl-5-pyrazolone (Hbutp, III ), and 4-isobutyryl-3-methyl-1-phenyl-5-pyrazolone (isobutp, IV ) have been isolated and characterized by various spectroscopic (FT-IR, UV/Vis, ¹H and ¹³C NMR) techniques, thermal analysis and single crystal X-ray analysis. These complexes adopt a distorted six-coordinate octahedral geometry where ligands act as bidentate, coordinating through the two O atoms. These complexes have been used as catalysts to explore a single pot multicomponent (benzaldehyde or its derivatives, urea/thiourea and ethyl acetoacetate/phenyl acetoacatate) Biginelli reaction producing biologically active 3,4-dihydropyrimidin-2-(1H)-one and 3,4-dihydropyrimidin-2-(1H)-thione based biomolecules under solvent-free conditions. Presence of H₂O₂ improves the yield of dihydropyrimidin-2-(1H)-one but it acts as poison for the later molecule. Epoxidation of internal and terminal alkenes mainly resulted in the formation of the corresponding epoxide. The catalytic oxidative bromination of thymol, a reaction facilitated by vanadium dependent haloperoxidases, resulted in the formation of three product namely 2-bromothymol, 4-bromothymol and 2,4-bromothymol. Other phenol derivatives have also been brominated effectively.     

Cardiovascular Disease and Possible Ways in Which Lycopene Acts as an Efficient Cardio-Protectant against Different Cardiovascular Risk Factors

Foods rich in antioxidants such as lycopene have a major role in maintaining cardiac health. Lycopene, 80% of which can be obtained by consuming a common vegetable such as tomato, can prevent the disturbances that contribute to cardiovascular disease (CVD). The present work begins with a brief introduction to CVD and lycopene and its various properties such as bioavailability, pharmacokinetics, etc. In this review, the potential cardio-protective effects of lycopene that reduce the progression of CVD and thrombotic complications are detailed. Further, the protective effects of lycopene including in vitro, in vivo and clinical trials conducted on lycopene for CVD protective effects are explained. Finally, the controversial aspect of lycopene as a protective agent against CVD and toxicity are also mentioned.     

Synthesis,Crystal Structure,and Enhancement of the Efficacy of Metronidazole Against Entamoeba histolytica by Complexation with Palladium(II), Platinum(II), or Copper(II)

Reaction of trans‐[PdCl₂(DMSO)₂], cis‐[PtCl₂(DMSO)₂], and [Cu(OAc)₂]⋅H₂O with metronidazole (mnz) leads to the formation of new complexes, i.e., trans‐[PdCl₂(mnz)₂] ( 1 ), trans‐[PtCl₂(mnz)₂] ( 2 ), and trans‐[Cu₂(OAc)₄(mnz)₂] ( 3 ), respectively. Complexes 1 – 3 crystallize all in the centrosymmetric monoclinic space group P2₁/c with Z=8. Unit‐cell parameters for these complexes are: 1 , a=7.1328(14) Å, b=20.699(4) Å, c=7.1455(14) Å, and β=116.17(3)°; 2 , a=6.9169(14) Å, b=21.853(4) Å, c=6.7218(13) Å, and β=110.79(3)°; 3 , a=9.1663(18) Å, b=19.129(4) Å, c=8.9446(18) Å, and β=116.44(3)°. The complexes 1 and 2 maintain an ideal square‐planar geometry. In complex 3 , the H₂O molecules of the starting complex are replaced by metronidazole while maintaining a dimeric structure of [Cu(OAc)₂]. Each Cu ion has an ideal octahedral structure, though distortion occurs in the equatorial position where the acetato ligands are attached. The Cu Cu separation of 2.6343(8) Å indicates considerable metal‐metal interaction. The testing of the antiamoebic activity of these complexes against the protozoan parasite Entamoeba histolytica suggests that compound 1 – 3 might be endowed with important antiamoebic properties since they showed IC₅₀ values in a μM range better than metronidazole (Table 2). Thus, compound 1 displayed more effective amoebicidal activity than metronidazole (IC₅₀ values of 0.103 μM vs. 1.50 μM , resp.).     

Minimally deformed charged stellar model by gravitational decoupling in 5D Einstein–Gauss–Bonnet gravity

The European Physical Journal C - EOS is an open-source software for a variety of computational tasks in flavor physics. Its use cases include theory predictions within and beyond the Standard...     

Polymer‐anchored mononuclear and binuclear CuII Schiff‐base complexes: Impact of heterogenization on liquid phase catalytic oxidation of a series of alkenes

Liquid phase catalytic oxidation of a number of alkenes, for example, cyclohexene, cis‐cyclooctene, styrene, 1‐methyl cyclohexene and 1‐hexene, was performed using polymer‐anchored copper (II) complexes PS‐[Cu (sal‐sch)Cl] ( 5 ), PS‐[Cu (sal‐tch)Cl] ( 6 ), PS‐[CH₂{Cu (sal‐sch)Cl}₂] ( 7 ) and PS‐[CH₂{Cu (sal‐tch)Cl}₂] ( 8 ). Neat complexes [Cu (sal‐sch)Cl] ( 1 ), [Cu (sal‐tch)Cl] ( 2 ), [CH₂{Cu (sal‐sch)Cl}₂] ( 3 ) and [CH₂{Cu (sal‐tch)Cl}₂] ( 4 ) were isolated by reacting CuCl₂·2H₂O with [Hsal‐sch] ( I ), [Hsal‐tch] ( II ), [H₂bissal‐sch] ( III ) and [H₂bissal‐tch] ( IV ), respectively, in refluxing methanol. Complexes 1–4 have been covalently anchored in Merrifield resin through the amine nitrogen of the semicarbazide or thiosemicarbazide moiety. A number of analytical, spectroscopic and thermal techniques, such as CHNS analysis, Fourier transform‐infrared, UV–Vis, PMR, ¹³C‐NMR, electron paramagnetic resonance, scanning electron microscopy, energy‐dispersive X‐ray analysis, thermogravimetric analysis, atomic force microscopy, atomic absorption spectroscopy, and electrospray ionization‐mass spectrometry, were used to analyze and establish the molecular structure of the ligands ( I )–( IV ) and complexes ( 1 )–( 8 ) in solid state as well as in solution state. Grafted complexes 5 – 8 were employed as active catalysts for the oxidation of a series of alkenes in the presence of hydrogen peroxide. Copper hydroperoxo species ([Cu^III (sal‐sch)‐O‐O‐H]), which is believed to be the active intermediate, generated during the catalytic oxidation of alkenes, are identified. It was found that supported catalysts are very economical, green and efficient in contrast to their neat complexes as well as most of the recently reported heterogeneous catalysts.