Synthesis Of Dendrons Based On 1,3,5-Triazine And Their Fluorescent Enhancement To Eosin And Eu～(3+) Ion

1,3,5-Triazine in cyanuric chloride can bear harsh conditions, and the chlorine in cyanuric chloride is able to react with active hydrogen step by step by controlling temperature. It is selective to aliphatic primary amino group and hydroxyl, aliphatic and aromatic primary amino group, alcoholic hydroxyl and phenolic hydroxyl group that were in one molecule, so the protecting-deprotecting or inactivation-activation steps would not be necessary. In this paper a series of novel dendrons with 1,3,5-triazine structure were designed and synthesized. The synthesized compounds were investigated for fluorescent enhancement to eosin and Eu³⁺ ion. The contents were as follows:1. A series of novel dendrons with 1,3,5-triazine structure were synthesized by convergent strategy using cyanuric chloride, p-hydroxyazobenzene,β-naphthol, 1-hydroxyanthraquinone, 3,5-dihydroxybenzyl. They were the first generation p-phenyl-azo-phenyloxy-terminated dendron G1.0(DOT), the first generation naphthyloxy-terminated dendron G1.0(NOT), the first generation naphthyloxy-terminated and 1-anthraquinonoxy-cored dendron G(NOE), and the second generation naphthyloxy-terminated dendron G2.0(NOT). The effects of the stuff molar ratio, the variety and dosage of base, the reaction temperature and time on the yields of the products were investigated.2. The structure of the dendrons was characterized by elementary analysis, IR spectrum, ¹H-NMR and MS.3. The thermo stability and solubility of dendrons were investigated. G1.0(DOT), G1.0(NOT), G(NOE) and G2.0(NOT) possess fairly thermo stability, since they started to decompose at 300, 260, 350 and 290℃respectively. G1.0(DOT) was soluble in dichloromethane, tetrahydrofuran, ethyl acetate, acetone, 1, 4-dioxane, not soluble in water, petroleum ether, absolute alcohol. G1.0(NOT) was soluble in tetrahydrofuran, dichloromethane, 1, 4-dioxane, acetone, ethyl acetate, not soluble in petroleum ether, absolute alcohol, water. G2.0(NOT) was soluble in tetrahydrofuran, dichloromethane, 1, 4-dioxane, acetone, ethyl acetate, absolute alcohol, water, not soluble in petroleum ether.4. The energy transfer between dendrons and eosin or Eu³⁺ ion in solvent were investigated. When energy transfer systems were obtained from the interaction of G1.0(DOT), G1.0(NOT), G(NOE) and G2.0(NOT) with eosin or Eu³⁺ ion respectively, all the dendrons could partially transfer their absorbed energy to eosin and Eu³⁺ ion at a certain range of concentrations. The maximum fluorescent enhancement to eosin and Eu³⁺ ion was 2.5 and 11.7 fold respectively. Therank of the abilities of fluorescent enhancement of the dendrons was G2.0(NOT)＞G(NOE)＞G1.0(NOT)＞G1.0(DOT). Solvents contributed a great deal to fluorescent emission intensity of the energy transfer systems.