Applied Chemistry

Dihydro-3,4-dihydroxy-5-(hydroxymethyl)furan-2(3H)-one has been prepared in two steps from galactose. The first step potassium-2,3,4,5-tetrahedroxypentanoate was obtained in 64% yield and the title compound has been isolated in next step with 75% yield. The structures of the products were characterized by IR, 1H, 13C, mass and microanalysis study.

Some metal(II) complexes of mixed ligands-dimethydithiocarbamic and p-aminobenzoic acids were synthesized (M = Mn, Fe, Co, Ni, Cu and Zn) and characterized by solubility, percentage metal, conductivity, infrared and electronic spectra measurements. Infrared data showed that the dimethydithiocarbamic and p-aminobenzoic acids coordinated through the sulphur atoms, and the carboxylate oxygen atoms to the metal atoms respectively. Electronic spectra and room temperature magnetic moments corroborated equilibrium between high spin and low spin octahedral geometry (spin-crossover) for the Mn(II), Fe(II), Ni(II) and Co(II) complexes, while the Cu(II) and Zn(II) complexes were octahedral and mononuclear. The antimicrobial activities of the metal complexes against Escherichia spp, Streptococcus spp, Proteus sp, Candida sp, Salmonella sp, Bacillus spp, Staphylococcus sp and Pseudomonas spp showed that the Mn(II), Fe(II) and Zn(II) complexes had very good antimicrobial activities against these microbes with inhibitory zones range of 7.0-20.0, 7.0-20.0 and 9.0-27.0 mm respectively, just like Streptomycin (7.0-29.0 mm) proving their potentials as broad-spectrum antimicrobial agents in-vitro.

Density, Viscosity and Ultrasound velocity of Tetra ethyl lead in aqueous NaOH and aqueous KOH have been measured at varying concentrations at 30oC. The derived acoustic parameters like specific acoustic impedance (Z), intermolecular free length (Lf), relative association (Ra), isentropic compressibility (?s) etc. have been calculated using density, viscosity and ultrasound velocity data. These parameters are used to discuss the nature and extent of intermolecular interactions in the mixture.

A simple and efficient method has been developed for the synthesis of macrocyclic binuclear Schiff base ligand and their transition metal complexes of the type [M₂(L)X]  where M= Ni(II), Cu(II),   X=CH₃COO^? and [M₂(L)].X where M=Ni(II), Cu(II) and VO(II), X=4ClO₄^?, 2SO₄^2?. If the ligand have been synthesized by the condensation of 3,3’-diaminobenzidine with Phthaldehyde and O-phenylenediamine in the ratio 1:4:2. The prepared macrocyclic ligand and their metal complexes were structurally confirmed by analytical and spectral data and the bonding sites are the azomethine nitrogen atoms. The metal complexes exhibit different geometrical arrangements such as square planar and square pyramidal. The ligand and the complexes were evaluated for their antimicrobial activities. The results showed that this skeletal framework exhibit marked potency as antimicrobial agents.

Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) ions form complexes of the type [ML₂]xH₂O with the  Schiff  base, [{4-(methylsulfanyl)phenyl]imino}methyl]benzene-2,4-diol, using the phenolic O and imine N atoms. These compounds are characterized by microanalysis, conductance, ¹H NMR, infrared and electronic spectral measurements. The IR measurements reveal that the Zn(II) complex is in the trans-isomeric form while electronic measurements are corroborative of a four coordinate, tetrahedral/square-planar geometry for the metal complexes. None is an electrolyte in nitromethane, and all the complexes are air stable but decomposed on heating in the temperature range 210-330^oC. The antibacterial studies show that the ligand, the Mn(II), Co(II), and Zn(II) complexes are active against Staphylococcus aureus with inhibitory zones range of 9.0-17.0 mm.  The cytotoxic study shows that the Cu(II) complex has the best in-vitro anticancer activity against HT-29 (colon carcinoma) cells with an IC₅₀ value of 30.17 ?M, which is  about a quarter as active as Cis-platin.

In this analysis , experimental values of densities (?) and dynamic viscosities (?) in the binary mixtures of n-hexane, n-heptane and n-octane with diethyl malonate are reported over the whole range of mixture composition at T = (303.15, 308.15, 313.15 and 318.15) K. From these data, deviations in viscosity (??) and excess Gibbs free energy of activation of viscous flow (?G*E) have been evaluated. These results were fitted to Redlich–Kister polynomial equations to estimate the fitting coefficients and standard deviation. The results of the viscosity composition are discussed in the light of various viscosity equations suggested by Grunberg-Nissan, Katti-Chaudhri, Heric-Brewer and Hind et al. The deviation of the experimental values of the viscosity of the mixture from the mole fraction mixture law rules, are found to be negative and follow the order n-hexane < n-heptane < n-octane. The experiments on the constituted binaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.

The Cu(II) , Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Mn(II) and Fe(III) complexes of Schiff base 6-bromo-N’-(1-(5-chloro-2-hydroxyphenyl)ethylidine)-2-oxo-2H-chromen -3-carbohydrazide has been synthesized and characterized by various spectral techniques. The complexes were prepared by reacting the ligand and metal chloride of Cu(II), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Mn(II) and Fe(III) in ethanol to get a series of mononuclear complexes. The complexes were characterized by CHN analysis, conductivity measurements, magnetic susceptibility, IR, NMR, ESR, UV-Vis and X-ray Powder diffraction studies. By these spectral studies it is found that Cu(II), Co(II), Ni(II), Mn(II) and Fe(III) complexes have exhibited octahedral geometry where as the other Zn(II), Cd(II), and Hg(II), complexes have exhibited square pyramidal geometry. The ligand and its metal complexes have been screened for their antimicrobial activities. The prepared ligand shows low activity and its metal complexes shows moderate to good activity.

The Fourier transform Raman and Fourier transform infrared spectra of 4-chloro-3,5-xylenol (4C35X) have been recorded by using DFT calculations. The theoretical computational density functional theory (DFT/B3LYP) was performed at 6-311+G** levels to derive equilibrium geometry, vibrational wavenumbers, infrared intensities and Raman scattering activities. The complete vibrational assignment was performed on the basis of the potential energy distribution (PED), calculated with scaled quantum mechanics (SQM) method. The Mulliken atomic charges and Dipole moment have been calculated. The first-order hyperpolarizability has been computed using quantum chemical calculations. Electronic excitation energies, oscillator strength and nature of the respective excited states were calculated by the closed-shell singlet calculation method for the molecule.

The heterogeneous catalytic activity of synthetic phosphate for conjugate addition was studied. This catalyst was prepared by calcination a mixture of fluorapatite and sodium nitrate. The conjugate addition between p-methoxychalcone and thiophenol has been used as model reaction. A central composite design was successfully employed for experimental design and analysis of the results. The combined effect of reaction time (X1), solvent volume (X2), catalyst weight (X3) and impregnation ratio (X4) on the reaction yield (Y) was studied and optimized using response surface methodology.

This paper presents an experimental investigation on the effect of ? -irradiation dose, polyvinyl alcohol content and nano-calcined clay ratios of PVA-NCC-cement mortar composite. PVA-NCC-cement mortar composite was prepared by the addition of PVA on blended cement mortar with different percentages namely 2, 4, 6 and 8% by wt. of blended cement. The fresh composites were first cured at 100% relative humidity for 24 hours and then subjected to ? -irradiation dose namely 10, 20, 30 and 50 KGy. The irradiated composites were cured in water for 28 days. Physico-mechanical properties such as compressive strength, bulk density, total porosity and water absorption were tested according to standard specifications. XRD, SEM, TGA were carried out on some selected samples to evaluate the effect of different factors on crystallinity, microstructural and thermal behaviour of the composites. Results showed that, compressive strength and bulk density of the composites increased with increasing the absorbed dose and PVA contents for certain values and then decreased while, total porosity and water absorption behave in an opposite direction. XRD, SEM, TGA confirmed these conclusions.