Synthesis And Thermochemical Properties Of Fumaric Acid And Metal Complexes

Fumaric acid is composed of butene derived carboxylic acid, is a white odorless crystalline structure. It is monoclinic prismatic, acicular or flake powder. Its chemical formula is C4H4O4. Fumaric acid is insoluble in ethanol, slightly soluble in cold water, ether, benzene, but easily soluble in hot water. And it is also known as anti maleic acid or fumaric acid. When the purity is more than 99 %, it can be used as a pure taste sour agentis of the food. In addition, it is commonly used in the production of unsaturated polyester resin, and widely used in chemical industry, paint, food and increase plastic agent, resin and other fields because of the on-toxic and low corrosionof fumaric acid. Therefore the market foreground is very vast. This topic mainly synthesize series of metal complexes, and the thermodynamics properties of the compound were studied.(1) Synthesis and characterization of fumarate. Firstly synthesize eleven fumaric acid salts.Then X-ray single crystal diffraction, chemical analysis and thermal analysis techniques were used to determine the composition. Finally we got the crystallographic data and draw the crystal structures.(2) Fumaric acid salt complexes thermal chemistry research. Divided into four steps,specific as follows:(1)The heat capacities of the fumarate compounds were measured by using a precision automatic adiabatic calorimeter during the temperature range from 78 to 400 K, and the molar heat capacity curves related to the temperature were drawn.(2)Use the least-squares method to fit the experimental heat capacities for the fumarate compounds and then get one polynomial equation of heat capacities vs. temperature. The smoothed molar heat capacities and thermodynamic functions related to the standard reference temperature 298.15 K were calculated based on the fitted polynomial equations.(3)Design a thermochemical reaction according to the law of Hess. And use isoperibol solution-reaction calorimeter and a suitable solvent to measure the enthalpies of solution of the reactants and products and finally calculate the enthalpy of the reaction. Then the standard molar enthalpies of formation of the fumarate compounds were calculated according to the enthalpy of reaction and other known thermodynamic data. Finally, the rationality of the designed reaction was verified.(4)Finally, on the basis of Pitzer's electrolyte solution theory, the molar solution enthalpy of succinate in water at infinite dilution and Pitzer's parameters were calculated.