2 - Phosphonic Acid, Butane-1, 2,4 - Tricarboxylic Acid Synthesis And Structure-activity Relationship Of Quantitative Research

The synthesis path of 2-phosphono-butane-l,2,4-tricarboxylic acid is studied by using alkyl phosphate, butendioic acid dialklesters and methyl acrylate with the catalyst of sodium methylate. By the experiments, the effects of reaction time, reaction temperature and the concentration of catalyst are discussed and the product is given a high yield. The mechanism of reaction has been discussed here. The synthesized product is demonstrated by IR,MC,LC-MC,13C, 31P.The molecular structures of scale inhibitors play a crucial role on theirs' performance, so it is vital important to study the relationship between them. In this work, quantum chemical calculation on some organic phosphonic acids, 2-phospho no-butane-1,2,4 -tricarboxylic acid(PBTCA) and its isomeric compounds, which behave as scale inhibitors were carried out by using Density Functional Theory(DFT) methods of Gaussian98 program package, Onsager model was adopted to simulate the solvent effect. The highest occupied molecular energy level(EHOMo), lowest unoccupied molecular energy level(ELUMO); the differences between highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) energies(ELUMO-EHOMO), charge distribution and dipole were obtained at B3LYP/6-31G* level. The relationship model between performance and molecular structures of scale inhibitors has been built with these parameters from quantum calculation.