Synthesis, Anion Recognition Properties And Plant Growth Regulator Activities Of N-Benzoylthiourea Derivatives Containing Fluorine

Acylthiourea derivatives have been patented as antidiabetic, antiarthritic, antineoplastic, and anticoagulant and prostate disorder. Herbicidal, fungicidal, bactericidal, insecticidal and plant growth regulator activities have also been reported. In addition, N-substituted N'-carbonyl thiourea compounds have attracted considerable attention in recent years due to their anionic recognition properties and coordination ability with transition metal ions. Owing to their strong coordination ability, many acylthioureas are extensively utilized as the sequestering agent for copper sulfides and precious metals. Moreover, fluorinated aromatic compounds play an important role as intermediates or materials in preparation Pharmaceuticals, pesticides and dyes last decade. In this thesis, we have synthesized some novel N-flurobenzoyl-N'-phenylthiourea derivatives and studied on their anion recognition properties and activities of these compounds as plant growth regulators. The major contents are as follows:1. Researches in the development of anion recognition were briefly reviewed. The content of this chapter includes: ( i ) molecular of recognition, (ii) the structural characters of anions, (iii) noncovalent interactions existed in anion coordination, (iv) the development of anion recognition researchers of urea and thiourea derivative receptors, (v ) the development of anion recognition properties of thiourea in water-containing media.2. A novel series of N-flurobenzoyl-N'-phenylthiourea have been prepared by simple steps in good yields and characterized. The binding properties of some of the receptors with anions such as F^- Cl^- Br^-, CH₃COO^-, HSO₄^- and NO₃^- were examined by UV-Vis and ¹H NMR Spectroscopy methods. The results showed that these receptors had better selectivities for F^- and CH3COO^- in dimethyl sulfoxide (DMSO), but no evident binding with Cl^-, Br^-, HSO₄^- and NO₃^-. A clear color change was observed from light yellow to yellow upon addition of F^- or CH3COO^- to the solution of the receptor N-(3-flurobenzoyl)-N'-(2-nitrophenylthiourea) in DMSO. The UV-Vis data indicated that a 1:1 stoichiometry complex was formed between the receptor N-(3-flurobenzoyl)-N'-(2-nitrophenylthiourea) and anions, while ¹H NMR titrations confirmed hydrogen interaction between the receptors and anions. The binding properties for anions of these N-flurobenzoyl-N'-phenylthioureas and 5 N-benzoyl-N'-phenyl thiourea were examined by UV-vis and ¹H NMR Spectroscopy. By fluorination of the benzoyl chromophore, the receptors had higher binding affinity for tested anions than the receptor 5. Especially, we studied the anion binding efficiency of the receptor 4a N-(3-flurobenzoyl)-N'-phenylthiourea and 5 in DMSO and DMSO-water binary solutions in detail respectively. In pure DMSO, the receptors 4a and 5 had higher binding affinity for F^- over AcO^-. However, as the ratio of water to DMSO increases, we found the binding properties for tested anions of 4a and 5 changed in DMSO-water binary solutions. The receptors showed higher binding affinity and selective ability for AcO^- over F^- in dimethyl sulfoxide containing water with varied ratios. It was further demonstrated that the receptor 4a had higher binding affinity for AcO^- over F^- in DMSO-water binary solutions by studying the changes of red shifts of the absorption bands and the changes of the isosbestic point during the UV-Vis spectral titrations.3. This chapter is a brief review for plant growth regulator, the application values of acylthioureas derivatives and the properties and applications of fluorinated aromatic compounds.4. Three bis(2,2'-flurobenzoylthioureaphenyl)glycol ether were synthesized by simple steps. All of the synthesized compounds were investigated for plant growth regulation activity by the method of plate culture. According to the bioactivities tests, the bisthiourea derivatives showed better growth regulating activities for wheat and coleseed in their low concentration solutions than N-flurobenzoyl-N'-phenylthiourea and heteroauxing.