PANI-Fe3O4@ZnO nanocomposite as magnetically recoverable organometallic nanocatalyst promoted synthesis of new Azo chromene dyes and evaluation of their antioxidant and antimicrobial activities

Molecular Diversity - A new series of azo chromene dyes were synthesized via a facile cyclocondensation reaction of (E)-1,2-diphenyl-1-diazene and 4-aminocoumarin with 1:2 molar ratio catalyzed by...     

Ultrasonic accelerated efficient synthesis of aminobenzochromenes using Ag2Cr2O7 nanoparticles as a reusable heterogeneous catalyst

Ag₂Cr₂O₇ nanoparticles were found to be an exceedingly effective catalyst for the mild and green synthesis of aminobenzochromenes. The reaction was performed under ultrasonic irradiation as an innocuous tool and in water as a green solvent at room temperature. This method encompasses several sustainable and economic benefits.     

Aqueous-Mediated green synthesis of novel spiro[indole-quinazoline] derivatives using kit-6 mesoporous silica coated Fe3O4 nanoparticles as catalyst

In this work, a series of eight new spiro[3,4′]1,3-dihydro-2H-indol-2-one-2′-amino-4′,6′,7′,8′-tetrahydro-2′,5’(1’H,3’H)-quinazoline-diones were successfully synthesized through a three-component reaction of 1H-indole-2,3-diones (isatins), guanidine nitrate, and 1,3-cyclohexanediones, by use of Kit-6 mesoporous silica coated Fe₃O₄ nanoparticles (Fe₃O₄@SiO₂@KIT-6) as a highly efficient magnetically separable nanocatalyst in aqueous media at 60°C. Several notable features of thiseco-friendly protocol are high yields of products, short reaction times, operational simplicity, and the use of easily available and recyclable catalyst.     

Novel and efficient catalysts for the one-pot synthesis of 3,4-dihydropyrano[c]chromene derivatives in aqueous media

Diammonium hydrogen phosphate, (NH₄)₂HPO₄(DAHP), efficiently catalyzes the one-pot, three-component reaction of an aromatic aldehyde, malononitrile and 4-hydroxycoumarin in aqueous media under mild conditions at room temperature, to afford the corresponding dihydropyrano[c]chromenes in high yields. (S)-Proline has also been used as another neutral catalyst for this reaction at reflux.     

Carpet oscillator: A new megastable nonlinear oscillator with infinite islands of self-excited and hidden attractors

Polarisation of the particle spin can be an important problem for different plasmas. In this article, the contribution of the electron spin on the growth rate of the temperature anisotropy of electromagnetic instabilities has been investigated. Results show that polarisation of the electron spin will restrict the instability growth rate while instability can survive due to the spin-depolarised electrons even when the requested temperature anisotropy is vanished. Instability can reach the damping state exponentially due to the spin-polarised electrons while it can grow linearly due to the spin-depolarised (the semi-classical) electrons.     

Employing of Fe3O4/CuO/ZnO@MWCNT MNCs in the solvent-free synthesis of new cyanopyrroloazepine derivatives and investigation of biological activity

Molecular Diversity - In this research, we synthesized the Fe3O4/CuO/ZnO@MWCNT magnetic nanocomposites using water extract of Petasites hybridus rhizome, and the high performance of synthesized...     

Fe3O4 MNPs as a green catalyst for syntheses of functionalized [1,3]-oxazole and 1H-pyrrolo-[1,3]-oxazole derivatives and evaluation of their antioxidant activity

Molecular Diversity - In the present study, iron oxide magnetic nanoparticles (Fe3O4 MNPs) were synthesized in a green biosynthetic manner using aqueous extract of clover leaves. Fe3O4 MNPs were...     

TiO2 nanoparticles as an effective catalyst for the synthesis of hexahydro-2-quinolinecarboxylic acids derivatives

The one-pot three-component reaction of arylmethylidenepyruvic acids,1,3-cyclohexandiones and ammonium acetate provides an economical and efficient synthetic route to 5-oxo-4-aryl-l,4,5,6,7,8-hexahydro-2-quinolinecarboxylic acid 4 under solvent-free conditions using a catalytic amount of TiO₂ nanoparticles（TiO₂ NPs） as an effective heterogeneous catalyst.     

Quantum Mechanical Study of Substituent Dependence on the Structure,Spectroscopic (13C, 1H NMR and UV), NBO,Hyperpolarizability and HOMO?LUMO Analysis of Ru(NHC)2Cl2(CH‐p‐C6H4X) Complexes

In this work, we have explored the structural, electronic properties, ¹³C and ¹H NMR parameters and first hyperpolarizability of Ru(NHC)₂Cl₂(CH‐p‐C₆H₄X) complexes (XH, F, Cl, Me, NH₂, OH, CN, NO₂, CHO, COOH) by mpw1pw91 quantum method. The X‐substituent effect on structural parameters, frontier orbital energies, spectroscopic (¹H and ¹³C NMR, UV) of complex was carried out. The results indicate that the substituent has played a significant role on the structures and properties of complex. ¹H and ¹³C NMR chemical shifts were calculated by using the gauge‐invariant atomic orbital (GIAO) method. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were exhibited. In analyzing the bonding characteristics of this structure, Ru‐C_carbene and Ru‐C_NHC bonds were identified and characterized in details by Natural bond orbital (NBO) analysis.     

A new 4D chaotic system with hidden attractor and its engineering applications: Analog circuit design and field programmable gate array implementation

Nowadays, designing chaotic systems with hidden attractor is one of the most interesting topics in nonlinear dynamics and chaos. In this paper, a new 4D chaotic system is proposed. This new chaotic system has no equilibria, and so it belongs to the category of systems with hidden attractors. Dynamical features of this system are investigated with the help of its state-space portraits, bifurcation diagram, Lyapunov exponents diagram, and basin of attraction. Also a hardware realisation of this system is proposed by using field programmable gate arrays (FPGA). In addition, an electronic circuit design for the chaotic system is introduced.