Inhibiting Effect On Micrococcus Luteus Based On Rare Earth Complexes As Bacteriostatic Agent:Thermodynamics Analysis And Formula Composition

The diseases and pests of plants appear different drug resistance for common bactericides in agriculture, leading to the prevention decreased obviously. In order to prevent and control the diseases and pests of plants, it is very essential to synthesis the new bacteriostatic agent with high efficiency, low toxicity. Based on the antibacterial activity of rare earth salts and dibenzene carboxylic acid ligand, the main contents of this work are as follow.By using hydrothermal and solution reactions, six Ln(III)-based complexes with 4,4’-dicarboxy diphenyl sulfone and eight Ln(III)-based complexes with 4,4’-dicarboxy diphenyl ether have been synthesized, respectively. The structures and physicochemical properties of these complexes obtainted above have been characterized by elemental analyses, infrared spectrum, UV-Vis spectrum, X-ray powder diffraction, and TG-DTG.The calorimetry is used to detect the bacteriostasis on Micrococcus luteus derived from the title complexes and further receive thermograms which are analyzed by thermal dynamic model, obtaining the thermodynamic functions in the processes of growth and inhibition, and the thermodynamic parameters of growth rate constant (k), maximum heat power of growth phase (Pmax), generation time (TG) and inhibitory ratio (I). Thus, the antibacterial effect, the certain structure-activity relationships and the antibacterial mechanism of the complexes would be revealed.Employing the complex of [Sm2(SDBA)3(H2O)4(DMF)2]·H2O, the types and dosages of emulsifying agents, dispersing agents and dispersing agents have been determined by using microcalorimetry experiments, therefore, the formula of the bacteriostatic agent has been identified as follow:the ratios of complexes was 0.2%, emulsifying agents of calcium dodecylbenzene sulfonate was 1.5%, wetting agents of sodium lauryl sulphate was 1.5%, dispersing agents of sodium lignosulfonate was 2.0%, the dosage of DMF fall in the range of 25～40%, and the remaining capacity was filled with water. The project will provide thermodynamics basis and theoretical foundation for the investigations of this kind of bacteriostatic agent, affording a novel strategy for the research of pesticides composed of functional complexes.