Arun L. Patel

Synthesis, spectral investigation and catalytic aspects of entrapped VO(IV) and Cu(II) complexes into the supercages of zeolite-Y

VO(IV) and Cu(II) complexes with Schiff base ligand derived from 1-phenyl-3-methyl-4-formyl-2-pyrazolin-5-one (PMFP) and 2-amino phenol have been synthesized as their neat and entrapped complexes into the supercages of zeolite-Y. The compounds were characterized by chemical analysis (ICP-OES and elemental), electronic and/or UV reflectance spectra, FTIR spectroscopy, X-ray powder diffraction patterns, SEMs, BET and thermogravimetric (TG) analysis. All the prepared catalysts were tested on the liquid phase limonene oxidation reaction, using 30% H2O2 as an oxidant. Limonene glycol, carveol, carvone and limonene 1,2-epoxide were the main products obtained. It was observed that zeolite-Y entrapped complexes exhibited higher catalytic activity than neat complexes. The catalysts undergo no metal leaching and can be easily recovered and reused. The use of inexpensive catalyst and oxidant are significant practical advantages of this environmentally friendly process.

Polyaniline-Anchored Metal Salts for Michael Reaction of α,β-Unsaturated Ketones

Abstract A catalyst consisting of polyaniline-anchored metal salts is used as a Lewis acid to promote the Michael reaction of α,β-unsaturated ketones. The reaction is performed efficiently with imidazole, acetyl acetone, and ethyl acetate as Michel donors and chalcones as the acceptors under ultrasound irradiation.

Polyaniline coated on celite, a heterogeneous support for palladium: applications in catalytic Suzuki and one-pot Suzuki–aldol reactions

Particles of celite were coated with polyaniline, characterized and used as a support for heterogenization of palladium metal ions. The prepared heterogeneous palladium catalysts were screened for Suzuki–Miyaura and one-pot Suzuki–aldol reactions with high conversions. The process of heterogenization on celite reduces the PANI consumption ten-fold when anchoring palladium ions onto the support. The recyclable catalyst was also used for the sunlight mediated Suzuki–Miyaura reaction with good conversion.

Synthesis, photophysical, electrochemical and single-crystal x-ray diffraction study of (Z)-2-phenyl-3-(5-(4-(thiophen-2-yl)benzo[c][1,2,5]thiadiazol-7-yl)thiophen-2-yl)acrylonitrile

ABSTRACT The optical characteristics, redox properties, thermogravimetric stability and single-crystal X-ray diffraction study of (Z)-2-phenyl-3-(5-(4-(thiophen-2-yl)benzo[c][1,2,5]thiadiazol-7-yl)thiophen-2-yl)acrylonitrile are examined using ultraviolet–visible spectrophotometry, cyclic voltammetry, thermal gravimetric analysis–diffraction scanning calorimetry analysis, single-crystal X-ray diffraction and density functional theory calculations. Evidently, the crystal structure of compound 6 is sustained by a number of weak nonconventional intermolecular forces of attraction such as C-H … N, C-H … π donor–acceptor interactions. GRAPHICAL ABSTRACT

Polyaniline Supported FeCl 3 : An Effective Heterogeneous Catalyst for Biginelli Reaction

Polyaniline supported FeCl3 is prepared and tested as an efficient heterogeneous Lewis acidic catalyst for the Biginelli reaction. The catalyst PANI–FeCl3 shows excellent activity in the synthesis of dihydropyrimidinones from aldehydes in the three component reaction with urea and β-keto esters or 1,3-diketones. The catalyst was characterized by usual analytical and spectroscopic techniques.Graphical Abstract

Synthesis, characterization and electrochemistry of polycyclic fused aromatic pyrroles and their conjugated polymers

Polycyclic fused aromatic pyrrole-based compounds, benzodipyrrole, naphthobipyrrole and their alkylated derivatives, were synthesized and studied electrochemically. Amongst these, naphthobipyrrole having a tetracyclic fused aromatic structure was electrochemically polymerized to give the homopolymer of naphthobipyrrole, poly(naphthobipyrrole), indicating good reactivity of α,α′-pyrrolic positions towards oxidative coupling. As a strategic approach towards the synthesis of copolymers, naphthobipyrrole was copolymerized with arylaldehyde to afford poly(arylmethylene naphthobipyrrole) by exploring the reactivity of β,β′-pyrrolic positions. Moreover, optical and electrochemical studies showed that the copolymer possessed a low optical bandgap and an elevated HOMO level. The scan rate dependent cyclic voltammetry studies of the copolymer film showed the formation of an electroactive material.

Constructing a self-assembling C3-symmetric covalently linked (fused) donor–acceptor-type molecule containing a hexaazatriphenylene core

A C3-symmetric covalently linked (fused) molecule, HAT-IPN, comprising a 13 fused ring system was synthesized by a condensation-cyclisation reaction between hexaazatriphenylenehexacarboxylic acid trisanhydride and 4,5-diamino-1,2-dioctyloxybenzene. This fused system exhibits ambipolar behaviour due to an n-type HAT-core at the center and three outer p-type fused dialkoxybenzimidazole moieties, which is confirmed by cyclic voltammetry. The self-assembling nature of this disc-shaped donor–acceptor type system is evident in 13C NMR spectroscopy, dynamic light scattering studies, differential scanning calorimetry and atomic force microscopy (AFM) images, which illustrate the formation of the one-dimensional aggregates both in solution and in the film state; indicating its potential as an active component in organic electronic devices.

Synthesis and Characterization of N-Substituted Tetrahydroiso-quinoline Derivatives via a Pictet-Spengler Condensation

Synthesis of N-substituted 1,2,3,4 –tetrahydroisoquinoline derivatives and bis-isoquinoline has been carried out via a Pictet-Spengler condensation. Tetrahydroisoquinolines were obtained from 2-(3’,4’-dimethoxyphenyl) ethylamine in four steps. The entire synthesized compounds were characterized by IR, 1 H NMR and mass spectral data.