Block modification of rod-shaped π conjugated carbon frameworks with donor and acceptor groups toward highly fluorescent molecules: synthesis and emission characteristics
作者:Takanori Ochi、Yoshihiro Yamaguchi、Tateaki Wakamiya、Yoshio Matsubara、Zen-ichi Yoshida
DOI:10.1039/b717832h
日期:——
To create organic molecules that are highly fluorescent at a longer wavelength region, we investigated the synthesis (using Pd-catalyzed cross-coupling) and photophysical properties (Φf, λem, Ï, λabs, and ε) of the following Ï conjugated molecular rods consisting of p-phenyleneethynylene units modified by donor (OMe) and/or acceptor (CN) groups: (1) side-donor modification systems (SD systems), (2) side-acceptor modification systems (SA systems), and (3) systems consisting of a donor block and an acceptor block (BL systems). As a consequence, very high Φf values (>0.95) were obtained for BL systems. Bathochromic shifts of λem for the same Ï conjugation length were largest for BL systems. Thus we succeeded in creating highly efficient light emitters at a longer wavelength region by block modification (e.g., Φf = 0.97, λem = 464 nm for BL-9). Considerably intense solid emission (Φf â¼ 0.5) at a longer wavelength region (500â560 nm) was also found for BL systems. It has been found that BL-6 and BL-8 exhibit interesting two photon absorption characteristics.
为了创造在较长波长区域高度荧光的有机分子,我们研究了以下由供体(OMe)和/或受体(CN)修饰的对亚苯基乙炔单元组成的π共轭分子杆的合成(使用钯催化交叉耦合)和光物理性质(Φf,λem,τ,λabs,和ε):(1)侧供体修饰系统(SD系统),(2)侧受体修饰系统(SA系统),以及(3)由供体块和受体块组成的系统(BL系统)。因此,我们得到了非常高的Φf值(>0.95)用于BL系统。对于相同的π共轭长度,BL系统的λem的向红移位最大。因此,通过块修饰(例如,对于BL-9,Φf = 0.97,λem = 464 nm),我们成功地创造出了在较长波长区域高效发光体。我们还发现在较长波长区域(500–560 nm),BL系统表现出相当强烈的固态发射(Φf ≈ 0.5)。研究发现,BL-6和BL-8具有有趣的双光子吸收特性。