Creation of the cross type electron conjugated system strong fluorophore arranged donor- and acceptor- groups

本研究通过缩窄π-电子共轭体系，形成核心部分在中心，臂部在四个方向上有电子给体或电子受体基团，从而产生强荧光材料，并对结果进行了光物理化学讨论。发射的十字形四（苯乙基）苯的设计：用AM1计算研究HOMO-LUMO间隙，十字形电子共轭能力优于直线型电子共轭能力。因此，化合物1-4被设计和合成。采用sonogashira交叉偶联反应，以卤代1,4 -二取代苯（核心部分）与对取代苯乙基（臂部分）为原料合成了化合物1-4。综述了十字形四苯基乙基苯的光物理性质。吸光度（λ_<abs>）和吸光度（log ε）按非取代化合物(1)<电子供体（核心）化合物(2)<电子受体（侧臂）化合物(3)<电子供体（核心）/受体（侧臂）化合物(4)的顺序依次增大，发射波长（λ_<em>）呈红移。引入电子给受体基团后，荧光量子产率（Φ_f）也大大提高。化合物1、2、3和4增加了k_r值，降低了k_d值。考察了辐射和无辐射过程中Φ_f与动力学参数之间的关系。ΔΔS ^‡=ΔS_r ^‡——ΔS_d ^‡= 1 n k_r / k_dA好衬套之间的关系Φ_f和ΔΔS ^‡(Φ_f = 0.092ΔΔS ^‡+ 0.520)。推断ΔΔS^‡可能是分子在激发单重态α-共轭的度量。

In this study, creation of strong fluorescence material was carried out by the constriction of π-electron conjugation system forming core part in the center, arm part having electron donor or acceptor group in four direction, and result were discussed with photophysicochemically. The design of emitted cross shaped tetrakis(phenyletylnyl)benzenes: The cross types of electron conjugative ability was advantageous than a straight line type by the investigation of HOMO-LUMO gap using AM1 calculation. Thus, compounds 1-4 were designed and synthesized. Compounds 1-4 by the reaction of halogenated 1, 4-disubstituted-benzene(core part) with p-substituted phenyl ethynyl (arm part) were synthesized using sonogashira cross coupling reaction. Photophysical data of cross shaped tetrakis(phenylethynyl)benzenes were summarized. Absorption(λ_<abs>) and absorbancy (log ε) were increase in order of non-substitution compound(1) < electron donor(core) compound(2) < electron acceptor(side arms) compound(3) < electron donor(core)/acceptor(side arms) compound(4) and emission wavelength(λ_<em>) were red-shifted above orders. The fluorescence quantum yields (Φ_f) also greatly go up by the introducing the electronic donor acceptor group . The compound 1, 2, 3 and 4 increase the k_r values, and decrease the k_d values. Relationship exists between Φ_f and kinetic parameters for the radiative and radiationless process were examined. ΔΔS^‡=ΔS_r^‡-ΔS_d^‡=1n k_r/k_dA nice liner relationship between Φ_f and ΔΔS^‡(Φ_f= 0.092ΔΔS^‡+ 0.520). It is inferred that ΔΔS^‡ might be a measure for α-conjugation of the molecules at the exited singlet state.