Stoichiometry and Stability Constant Values for Copper (II) Chelates with Ethylene Diamine in Deep Eutectic Solvents (DES) (Ethaline) Solutions

In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements have been applied for establishing, the stoichiometry and whenever possible, the stability constants of the chelates formed. The method of continuous variations was necessary to determine first whether, the metal ion and the ligand ethylene diamine form one or more than one chelate, when more than one chelate formed, the results obtained depend on the wavelength and for meaningful conclusions the wavelengths were carefully selected. The empirical formulae of the chelates were further substantiated by the molar ratio method. The effect of time and temperature on the formation and stability of these chelates in solution is also studied. The stability constants, K1 and K2 for the copper (II) chelates were calculated, though reliable, and are comparable to literature values.

Synthesis of 2-methylpyrazine from cyclocondensation of ethylene diamine and propylene glycol over promoted copper catalyst

The 2-methylpyrazine was synthesized by catalytic reaction of ethylene diamine and propylene glycol at 380 ℃. The alumina supported copper catalysts with promoter were prepared by impregnation method, characterized by ICP-AES, BET and TPR. The results demonstrated that the dehydrogenation was improved by addition of chromium promoter. The selectivity of 2-methylpyrazine reached 84.75%, while the conversions of reactants were also enhanced.

Synthesis, Crystal Structure and Thermal Properties of N,N′-Bis(5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl) Ethylene Diamine

The title compound N,N＇-bis（5,5-dimethyl-2-phospha-2-thio-1,3-dioxan-2-yl） ethylene diamine （DPTDEDA, C12H26N2O4P2S2） was synthesized by the reaction of neopentyl glycol, phosphorus thio-chloride and 1,2-ethylenediamine, and characterized by elemental analysis, IR and ^1H NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction analysis and the thermal property was analyzed by TG analysis. The crystal structure belongs to monoclinic, space group P21/c, with a = 14.557（16）, b = 11.299（12）, c = 12.163（13）A,β = 98.707（19）^o, Dc = 1.305 g/cm^3, Z = 4, γ = 0.71073A,μ（MoKa） = 0.447 mm^-1, Mr = 388.41, V = 1977（4）A3, F（000） = 824, S = 1.107, the final R = 0.0478 and wR = 0.0810 for 1738 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the crystal structure is centrosymmetrically distributed through 1,2-ethylenediamine to join two distorted six-membered rings. The weak N-H…S interactions are observed and link the molecules into sheets. TG analysis shows that the title compound has good thermal stability and char-forming capability, which are required for an excellent intumescent fire retardant.

Synthesis and Characterization of Trivalent Al Substituted Zinc Ferrite using Ethylene Diamine (EDA) as Ligand

Nano domain Al substituted Zinc ferrite was prepared by chemical route using Ethylene Diamine as ligand.High purity precursors nitrate salts of Zinc,Fe(3+),Al(3+)were utilized along with citric acid which acts as both fuel and complexing agent.Two different molar ratios of Zn(2+):(Fe3+):Al(3+)is 1:1.5:0.5 and 1:1.25:0.75.After ensuring proper mix of the solution Ethylene diamine was added dropwise to form a gel like mass with proper pH control.Before annealing,thermal analysis was carried to determine the crystallization/phase transition zone.Drying was carried in several stages.Initially,gel like mass was obtained after drying at 40°C while pH was about 7.Drying of gel was carried in oil bath at about 90°C and powdered mass obtained was grinded followed by auto combustion at 150°C for 60 minutes before annealing at 150°C,350°C,650°C,950°C for 2 hours to ensure the phase formation.Crystallite size,lattice strain and lattice parameters were studied from XRD analysis.

Effect of chromium on accumulation and antioxidants in Cucumis utillissimus L.:Response under enhanced bioavailability condition

This study compares the accumulation of Cr（VI） and biochemical changes （total chlorophyll, carotenoid, protein, malondialdehyde （MDA） and cysteine contents） and roles of antioxidant enzymes （superoxide dismutase （SOD）, guaiacol peroxidase （GPX）, ascorbate peroxidase （APX）） in tolerance to metal induced stress in Cucumis utiUissimus L. grown in Cr contaminated soil （CS） with garden soil （GS）. Furthermore, Cr bioavailability was enhanced by ethylene diamine tetra-acetic acid （EDTA） addition to the soil to forecast the plant＇s accumulation pattern at elevated Cr environment. Accumulation of Cr in the leaves of the plant increased with increase in substrate metals concentration. It further increased with the addition of EDTA by 1437% and 487% in GS and CS, respectively at the highest treatment level. The lipid peroxidation increased proportionately with increase in Cr accumulation in the leaves. All the activity of antioxidant enzymes （SOD, GPX and APX） and the level of cysteine increased with dose dependant manner. SOD and cysteine were observed to be higher in the GS than in CS, but APX and GPX were found to be higher in CS than in GS, The increase in GPX and APX activities with the increase in Cr concentration could be assumed that these two enzymes have a major role in the defense mechanism towards stress induced by Cr in C. utillissimus.

Facile Synthesis of Dendritic Hydroxyl-terminated Cyanuric Chloride Derivatives and Their Properties

Novel dendritic compounds G1.5（OH）4 and G1.5（OH）8 with peripheral hydroxyl were synthesized under mild conditions from eyanuric chloride, ethylene diamine, ethanolamine and diethanolamine. The products could be separated and purified through dispersion and precipitation in organic solvents with good yields （over 93.0%） and high purity （above 98.0%, HPLC）. The structures of the products were characterized by 1R, MS, 1H NMR and elementary analysis. G1.5（OH）4 and Gl.5（OH）8 could be dissolved in polar solvents such as methanol, water and dimethylsulfoxide. TGA analysis showed that G1.5（OH）4 and G1.5（OH）8 had good thermo stability. The aqueous solutions ofG1.5（OH）4 and G1.5（OH）8 exhibited low surface tension.