American Journal of Chemical Research

  • Synthesis, Characterization and catalytic activity of Palladium-Based Metallodendrimer with Triazine

    A novel Pd-based metallodendrimer has been directly prepared by the reaction of substituted triazine with substituted benzoyl chloride in good yields using (Ph3P)2PdCl2 and DMF at 70 oC. This procedure avoids the use of high temperature and severe reaction conditions. The surface morphology like as entangled nanofibers from SEM image and the presence of Palladium ions of the compound from EDX analysis were obtained in addition TG and DSC showed the good thermal stability of the compound. This white solid compound was found to be an effective homogeneous catalyst for the synthesis of ynones in where the synthetic route was copper and phosphine ligand-free.

  • Chemo-Remediation of Crude Oil Polluted Soils Obtained from Recent Polluted Site in Oil Producing Environs in Rivers State Nigeria

    The chemo- remediation of crude oil polluted soils from recent pollution sites in oil producing environs in River state was carried out by both in vivo and in vitro methods using macro-soil nutrients ( Nitrate, Phosphate and Potassium) as index for remediation. The soil samples were labeled A, B, C, D1 to D6, sample A was obtained from pollution free site used as a control. Sample C was crude oil polluted soil not treated with surfactant, sample B was crude oil polluted soil leached with surfactant and not mineralized. Samples D1-D6 were polluted soil samples, leached with surfactant and mineralized with fertilizer. The samples were leached with linear alkyl benzene sulphonate (LABS) and later mineralized with Nitrate, Phosphate and Potassium (N.P.K) fertilizer and returned to the site of excavation to fallow for four months. The samples were later re-excavated and taken to the laboratory for analysis. Nitrate and phosphate contents were obtained with the aid of spectrum lab 725 UV visible spectrophotometer and potassium content was determined by use of a flame photometer. Results showed that sample A had nitrate concentration of 330ppm, sample B had concentration of 21ppm, sample C had a concentration of 54ppm while samples D-D6 had concentrations ranging from300ppm to 420ppm.Similarly, The phosphate concentrations were 68.50ppm, 17.00ppn, 28.00ppm and 48.80-136.40ppm for sample A, B, C.D1-D6 respectively. The potassium concentrations were not different as concentrations of 46ppm, 12ppm, 28ppm and 38ppm-64ppm was recorded for samples A, B, C, and D1-D6 respectively. These results revealed that crude oils not only renders soils unusable but also destroys the nutrient availability in soils. The soils can therefore quickly be reclaimed by leaching them with surfactants and mineralizing them with adequate inorganic fertilizer.

  • ORGANODIPHOSPHINES IN PtP2X2 (X = Br or I) DERIVATIVES – STRUCTURAL ASPECTS

    Baeyer-VillThis review covers twenty eight monomeric Pt(η2-P2L)X2 (X = Br or I) derivatives. These complexes exist in cis- as well as trans-configurations from which the complexes with cis-configuration are more common. The organodiphosphines create wide varieties of the metallocyclic rings PNP, PC2P, PC3P, PNCNP and PC4OC4P. The mean values of Pt-L bond distances in cis-complexes are: 2.230 Å (P), 2.490 Å (Br) and 2.240 Å (P) 2.666Å (I), respectively. In the trans-complexes the values are 2.319 Å (P), 2.429 Å (Br) and 2.320 Å (P), 2.615 Å (I). The Pt-X bond distances in the cis- as well as in the trans-derivatives elongate with the covalent radius of the X atom. In addition in the cis-derivatives the Pt-X bond distances are longer than those in trans-derivatives, as a reason of higher trans-influence of P over the respective halogens. Some of the complexes are examples of distortion isomerism. Finally, the structural data of Pt(η2-P2L)X2 (X = Br or I) are compared with the values of Pt(η2-P2L)X2, complex and discussed.

  • Synthesis of Bicyclic Adduct through Regioselective Baeyer-Villager oxidation

    Baeyer-Villager oxidation reaction has become accepted as a right approach in the ring expansions for the preparation of both bicyclic and tricyclic lacotnes; however, successful application of the regioselective Bayer-Villager oxidation protocol to the synthesis of particularly congested scaffolds remains distinctly tricky. Herein the Baeyer–Villiger oxidation of Bicyclo[3.2.0]hept-3-ene-6-one is studied with oxygen insertion leading to the functionalized oxabicyclic adduct with complete regioselectivity.

  • Organodiphosphines in Monomeric PtP2X2 (X = OL, NL, CN, BL) Derivatives Structural Aspects

    In this review are classified and analyzed structural parameters of over seventy examples of monomeric PtP2X2 (X = OL, NL, CN or BL) derivatives in which P donor ligands are organodiphosphines. These complexes crystallize in four crystal systems: tetragonal (x1), triclinic (x11), orthorhombic (x19) and monoclinic (x40). The complexes were divided into the two groups: Pt(η2-P2L)(XL)2 (X = O, N, CN or B) and Pt(η2-P2L)(η2-X2L) (X = O or N). The chelating ligands create wide of metallocyclic rings and the effects of both steric and electronic factors influence on the values of L-Pt-L bite angles. The some cooperative effects were found and are discussed with trans-influence of the respective donor atoms.

  • Synthesis, Characterization and Antimicrobial Properties of Pd(II), Cr(III), Ni(II) and Co(II) Metal Complexes of Aniline and Sulphadiazine Schiff Bases as mixed Ligands

    Novel Pd(II), Cr(III), Ni(II) and Co(II) metal complexes of Schiff bases were synthesized from the condensation reaction between salicylaldehyde and aniline (L1) and sulphadiazine (L2). They were characterized using FTIR and UV-Visible spectroscopy and subjected to conductivity, melting point and solubility measurements. The complexes are non-toxic, non-electrolytic and stable solids. The involvement of the azomethine nitrogen in coordination with the metals was confirmed by the IR and UV results. They showed good inhibitory activities against various microorganisms.

  • Kinetics of Acidic Mn(VII) Oxidation of Acetaldehyde in Aqueous and 5% Ethanol-Water Solvents

    Kinetics of acidic Mn(VII) oxidation of acetaldehyde in aqueous and 5% ethanol-water solvents were studied via pseudo-first order condition at λmax 525nm. The reaction showed a first order dependence with respect to acetaldehyde concentration, [Mn(VII)], fractional order to [H+] and independent on the ionic strength of the solution. Michaelis-Menten plot showed the existence of an intermediate complex and dependence on hydrogen ion is in the form kobs= a + b[H+]. However, oxidation reaction is generally faster in non-aqueous solvent than in aqueous solvent. Product analysis revealed the presence of carboxylic acid and stoichiometric study suggests the consumption of 2 moles of MnO4- by 3 moles of acetaldehyde in both solvents. Thermodynamic parameters of activation were obtained from Arrhenius and Erying’s equations. A plausible associative mechanism in agreement with kinetic and spectroscopic results was proposed.

  • Nanocomposites for Additive Manufacturing

    Additive Manufacturing (AM) is one of several technological breakthroughs that is expected to lead the factories of the future, where conventional equipment will be transformed into smart and flexible systems, run by computers that will allow the fabrication of customized parts. Some authors have called AM the third industrial revolution, as it enables the accurate manufacture of pieces of virtually any shape in different scales, ranging from visual prototypes to specific functional end-use products at relatively short periods of time. Medical applications of AM is one of the key industries driving the innovations in the field, especially because of the possibility to fabricate products individually tailored to the patient’s specific needs. The integration of nanomaterials in the area of AM has a lot of potential and there is a growing interest in academia and industry to explore for new developments. In this section, we examine some successful uses of nanocomposites in additive manufacturing processes.

  • Evaluation of cassava (Manihot Esculentum) seed waste Activated carbon for kinetic study on methylene blue dye adsorption from aqueous solution

    The effect of activation temperature on activated carbon was studied at 400o C, 500oC and 600oC respectively. The characterization properties showed that increased in temperature reduces yield, moisture content, ash content and volatile content but increased fixed carbon, pore volume and porosity. Batch experiment was conducted by varying the dosage of activated carbon (0.2g – 0.6g) and contact time (40 -120 min) on adsorption of methylene blue dye from aqueous solution. The experimental data was fitted to pseudo first and second order kinetics in order to verify the rate controlling mechanism. The pseudo second order model showed a better fit with the highest correlation coefficient of 0.998. The adsorption capacity q computed was found to be 6.561 mg/g and 16.129 mg/g showed deviation from the experimental value of 11.00 mg/g for the both kinetics. The equilibrated isotherm data was also fitted to Langmuir, Freundlich and Dabinin-Radushkevich. Freundlich model has the best fit with R2 = 0.914. The energy of adsorption was calculated using the Dabinin-Radushkevich model and found to be 5.89 kJ/ mol.

  • Thio-ligands in Monomeric Pt(Ii) Complexes – Structural Aspects

    This review includes over three hundred derivatives in which each Pt(II) atom is in a distorted square planar environment with inner coordination spheres of PtS4, PtS3X, PtS2X2, PtSX3, PtS2XY, PtSX2Y and PtSXYZ. There is a wide variety of mono-, bi- , ter- , and tetra-dentate ligands, all incorporating both homo- and hetero-dentate varieties. The most common ligands are dimethylsulphoxide and triphenylphosphine. The chelating ligands create a wide variety of metallocyclic rings, where the effects of both steric and electronic factors are observed. Examples of cis– and trans– isomerism exists in these derivatives as well as distortion isomerism, which is much more common. Ligands exerting the trans– effect in these Pt(II) complexes are stronger in the order: OL, NL < Cl < Br < I < SL < H ~ AsL ~ PL ~ CN. Several relationships between the structural parameters were found and are discussed. The complexes crystallized in five crystal classes: hexagonal (0.4%) < tetragonal (1.5%) < orthorhombic (13.8%) < triclinic (23.7%) < monoclinic (60.7%).