Kumar Dhirendra, Thomas K R Justin, Lee Chuan-Pei, Ho Kuo-Chuan
Organic Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee , Roorkee 247 667, India.
J Org Chem. 2014 Apr 4;79(7):3159-72. doi: 10.1021/jo500330r. Epub 2014 Mar 24.
New organic dyes containing fluorene functionalized with two imidazole chromophores as donors and cyanoacrylic acid acceptors have been synthesized and successfully demonstrated as sensitizers in nanocrystalline TiO2-based dye-sensitized solar cells (DSSCs). The monoimidazole analogues were also synthesized for comparison. The Sommelet reaction of bromomethylated 2-bromo-9,9-diethyl-9H-fluorene produced the key precursor 7-bromo-9,9-diethyl-9H-fluorene-2,4-dicarbaldehyde required for the preparation of imidazole-functionalized fluorenes. Since the dyes possess weak donor segment, the electron-richness of the conjugation pathway dictated the optical, electrochemical, and photovoltaic properties of the dyes. The dyes served as sensitizers in DSSC and exhibited moderate efficiency up to 3.44%. The additional imidazole present on the fluorene has been found to retard the electron recombination due to the bulkier hydrophobic environment and led to high open-circuit voltage in the devices.
已合成了含有芴的新型有机染料，芴用两个咪唑发色团作为供体和氰基丙烯酸受体进行功能化，并成功地在基于纳米晶二氧化钛的染料敏化太阳能电池（DSSC）中作为敏化剂得到证明。还合成了单咪唑类似物用于比较。溴甲基化的2-溴-9,9-二乙基-9H-芴的索姆莱反应产生了制备咪唑功能化芴所需的关键前体7-溴-9,9-二乙基-9H-芴-2,4-二甲醛。由于这些染料具有较弱的供体片段，共轭途径的富电子性决定了染料的光学、电化学和光伏性质。这些染料在DSSC中用作敏化剂，表现出高达3.44%的中等效率。已发现芴上存在的额外咪唑由于更庞大的疏水环境而阻碍了电子复合，并导致器件中的高开路电压。
