Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

New trans-disubstituted macrocyclic ligands, 1,8-[N,N-bis(3-formyl-12- hydroxy-5-methyl)benzyl]-5,12-dioxo-1,4,8,11-tetraazacyclotetradecane (L 1), 1,8-[N,N-bis(3-formyl-12-hydroxy-5-bromo)benzyl]-5,12-dioxo-1,4, 8,11-tetraazacyclotetradecane (L2), N,N-bis[1,8-dibenzoyl]-5,12- dioxo-1,4,8,11-tetraazacyclotetradecane (L3), N,N-bis[1,8-(2- nitrobenzoyl)]-5,12-dioxo-1,4,8,11-tetraazacyclotetradecane (L4), and N,N-bis[1,8-(4-nitrobenzoyl)]-5,12-dioxo-1,4,8,11-tetraazacyclotetradecane (L5) were synthesized. The ligands were characterized by elemental analysis, FT IR, 1H NMR and mass spectrometry studies. The crystal structure of L1 is also reported. The copper(II) and nickel(II) complexes of these ligands were prepared and characterized by elemental analysis, FT IR, UV-Vis and mass spectral studies. The cyclic voltammogram of the complexes of ligand L1-3 show one-electron quasi-reversible reduction wave in the region -0.65 to -1.13 V, whereas that of L4 and L5 show two quasi-reversible reduction peaks. Nickel(II) complexes show one electron quasi-reversible oxidation wave at a positive potential in the range +0.95 to +1.06 V. The ESR spectra of the mononuclear copper(II) complexes show four lines, characteristic of square-planar geometry with nuclear hyperfine spin 3/2. All copper(II) complexes show a normal room temperature magnetic moment value Î¼eff 1.70-1.73 BM which is close to the spin only value of 1.73 BM. Kinetic studies on the oxidation of pyrocatechol to o-quinone using the copper(II) complexes as catalysts and hydrolysis of 4-nitrophenylphosphate using the copper(II) and nickel(II) complexes as catalysts were carried out. The ligands and their complexes were also screened for antimicrobial activity against Gram-positive, Gram-negative bacteria and human pathogenic fungi. Â© 2010 Elsevier Ltd. All rights reserved.

Department of Chemical Engineering

School of Chemical Engineering

Vellore Campus

World University root node

Polyhedron

Synthesis, characterization, crystal structure and antimicrobial activities of new trans N,N-substituted macrocyclic dioxocyclam and their copper(II) and nickel(II) complexes

A series of N-benzoylated cyclam ligands incorporating three different benzoyl groups 1,4,8,11-tetra-(benzoyl)-1,4,8,11-tetraazacyclotetradecane (L1), 1,4,8,11-tetra-(2-nitrobenzoyl)-1,4,8,11- tetraazacyclotetradecane (L2) and 1,4,8,11-tetra-(4-nitrobenzoyl)-1, 4,8,11-tetraazacyclotetradecane (L3) and their nickel(II) and copper(II) complexes are described. Crystal structure of L1 is also reported. The ligands and complexes were characterized by elemental analysis, electronic, IR, 1H NMR and 13C NMR spectral studies. N-benzoylation causes red shift in the Î»max values of the complexes. The cyclic voltammogram of the complexes of ligand L1 show one-electron, quasi-reversible reduction wave in the region -1.00 to -1.04 V, whereas that of L2 and L3 show two quasi-reversible reduction peaks. Nickel complexes show one-electron quasi-reversible oxidation wave at a positive potential in the range +1.05 to +1.15 V. The ESR spectra of the mononuclear copper(II) complexes show four lines, characteristic of square-planar geometry with nuclear hyperfine spin 3/2. All copper(II) complexes show a normal room temperature magnetic moment values Î¼eff 1.70-1.73 BM which is close to the spin-only value of 1.73 BM. Kinetic studies on the oxidation of pyrocatechol to o-quinone using the copper(II) complexes as catalysts and hydrolysis of 4-nitrophenylphosphate using the copper(II) and nickel(II) complexes as catalysts were carried out. All the ligands and their complexes were also screened for antimicrobial activity against Gram-positive, Gram-negative bacteria and human pathogenic fungi. Â© 2010 Elsevier B.V.

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

N-benzoylated 1,4,8,11-tetraazacyclotetradecane and their copper(II) and nickel(II) complexes: Spectral, magnetic, electrochemical, crystal structure, catalytic and antimicrobial studies

New N-substituted cyclam ligands 1,8-[bis(3-formyl-2-hydroxy-5-methyl) benzyl]-1,4,8,11-tetraazacyclotetradecane, 1,8-[bis(3-formyl-2-hydroxy-5-methyl) benzyl]-4,11-dimethyl-1,4,8,11-tetraazacyclotetradecane, 1,8-[bis(3-formyl-2- hydroxy-5-bromo)benzyl]-1,4,8,11-tetraazacyclotetradecane, and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-4,11-dimethyl-1,4,8, 11-tetraazacyclotetradecane (L1-L4) were synthesized and mononuclear copper(II) and nickel(II) complexes prepared. The ligands and complexes were characterized by elemental analysis, electronic, IR, 1H NMR and 13C NMR spectral studies. N-alkylation causes red shifts in the λmax values of the complexes. Copper(II) complexes show one-electron, quasi-reversible reduction waves in the range -1.04 to -1.00 V. The nickel(II) complexes show one-electron, quasi-reversible reduction waves in the range -1.18 to -1.30 V and one-electron, quasi-reversible oxidation waves in the range +1.20 to +1.40 V. The reduction potential of the copper(II) and nickel(II) complexes of the ligands L1 to L2 and L3 to L4 shift anodically on N-alkylation. The ESR spectra of the mononuclear copper(II) complexes show four lines, characteristic of square-planar geometry with nuclear hyperfine spin 3/2. All copper(II) complexes show a normal room temperature magnetic moment value μeff = 1.70-1.74 BM which is close to the spin only value of 1.73 BM. Kinetic studies on the oxidation of pyrocatechol to o-quinone using the copper(II) complexes as catalysts and on the hydrolysis of 4-nitrophenylphosphate using the copper(II) and nickel(II) complexes as catalyst were carried out. The tetra-N-substituted complexes have higher rate constants than the corresponding disubstituted complexes. © 2008 Taylor & Francis.

Journal of Coordination Chemistry

Synthesis, spectral, magnetic, electrochemical and catalytic studies of cyclam-based copper(II) and nickel(II) complexes - Effect of N-substitution

Expanded polystyrene is one of the polymers produced in large quantities due to its versatile application in different fields. This polymer is one of the most intractable components in municipal solid waste. Disposal of polymeric material by pyrolysis or catalytic cracking yields valuable hydrocarbon fuels or monomers. Literature reports different types of reactors and arrangements that have uniform temperatures during pyrolysis and catalytic cracking. The present study focuses on reducing the temperature to maximize the quantity of styrene monomer in the liquid product. A bench scale reactor has been developed to recover the styrene monomer and other valuable chemicals. Experiments were carried under partial oxidation and vacuum conditions in the temperature range of 300-500 °C. In the pyrolysis optimization studies, the best atmospheric condition was determined to be vacuum, the pyrolysis temperature should be 500 °C, yield of liquid product obtained was 91.7% and yield of styrene obtained was 85.5%. In the characterization studies, distillation and IR spectroscopy experiments were carried out. The remaining of the liquid product comprises of benzene, ethyl benzene, and styrene dimers and trimers. © 2007 Elsevier Ltd. All rights reserved.

VIT Unitversity

Waste Management

Thermal decomposition of expanded polystyrene in a pebble bed reactor to get higher liquid fraction yield at low temperatures

A series of novel unsymmetrical dicompartmental binuclear nickel(II) complexes have been prepared by simple Schiff base condensation of the compound 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-l,4,8,11-tetraazacyclotetradecane L with appropriate aliphatic or aromatic diamine, nickel(II) perchlorate and triethylamine. All the complexes were characterized by elemental and spectral analysis. Positive ion FAB mass spectra show the presence of dinickel core in the complexes. The electronic spectra of the complexes show the d-d transition in the range of 550-1040 nm. Electrochemical studies of the complexes show two irreversible one electron reduction process around Epc1 = - 0.79 to - 1.27 V and Epc2 = - 1.28 to - 1.43 V. The reduction potential of the binuclear nickel(II) complexes shifts towards anodically upon increasing chain length of the macrocyclic ring. All the nickel(II) complexes show two irreversible oxidation waves around 0.72 to +1.52 V. The observed rate constant values for catalysis of the hydrolysis of 4-nitrophenyl phosphate are in the range of 9.20 Ã 10-3-16.81 Ã 10-3 min-1. The rate constant values for the complexes containing aliphatic diimines are found to be higher than that of the complexes containing aromatic diimines. Spectral, electrochemical and catalytic studies of the complexes were compared on the basis of increasing chain length of the imine compartment. All the complexes were screened for antifungal and anti bacterial activity. Â© 2008 Elsevier Ltd. All rights reserved.

Synthesis, electrochemical, catalytic and antimicrobial activities of novel unsymmetrical macrocyclic dicompartmental binuclear nickel(II) complexes

Boiling temperatures at 95 kPa, over the entire composition range, have been measured for the binary mixtures trichloroethylene with ethanol, isopropanol, and isobutanol, and tetrachloroethylene with methanol by using a Swietoslawski type ebulliometer. The liquid-phase composition versus temperature measurements are well represented by the Wilson model.

Journal of Chemical and Engineering Data

Vapor-liquid equilibria in trichloroethylene + ethanol, + isopropanol, and + isobutanol and in tetrachloroethylene + methanol at 95 kPa

Densities and viscosities of the binary mixtures of tetrachloroethylene with methanol and of trichloroethylene with ethanol, 2-propanol, and isobutanol were measured at 303.15, 313.15, and 323.15 K. The measurements were used to compute the excess volumes (VE) and deviations in viscosity (Δη). The excess volumes and deviations in viscosity were represented by a Redlich and Kister expression.

Densities and viscosities of the binary mixtures of chloroethylenes with some aliphatic alcohols

Experimental measurements of gas phase hold up in two phase gas-liquid cocurrent upflow packed bed reactors have been made at very low gas ((N(Re))(g) &lt; 55) as well as liquid ((N(Re)1 &lt; 8) velocities using air- water systems with two different types of packing materials. The gas hold up values thus obtained are correlated in terms of Re(g), Re1 and ε, the voidage.