1,1-双(1H-苯并咪唑-2-基)-1-十三碳烯的合成及其性能

以邻苯二胺和丙二酸为原料,在3 mol/L盐酸催化下合成双(1H-苯并咪唑-2-基)甲烷中间体,然后与月桂醛通过Knoevenagel缩合反应合成了双苯并咪唑衍生物——1,1-双(1H-苯并咪唑-2-基)-1-十三碳烯。利用元素分析、FTIR和~1HNMR对合成产物的结构进行了表征,考察了常规碱催化剂对目标产物收率的影响,并通过UVVis和荧光光谱(FL)测定了目标化合物的光学性能。结果表明:六氢吡啶催化效果最好,产物收率可达76.33%。目标化合物在243、315和361 nm 3处有紫外吸收峰,可有效覆盖日光紫外线UVA和UVB波段;目标化合物溶液在λem=464.5 nm处有蓝紫色荧光,固体薄膜在λ_(em)=476.5 nm处有蓝紫色荧光,荧光量子产率为0.47。标题化合物荧光增白效果与常用荧光增白剂VBL相当。

Synthesis and Properties of 1,1-bis (1H-benzimidazole-2-yl) -1- tridecylene

The intermediate bis(1H-benzimidazole-2-yl) methane was synthesized by using o-phenylenediamine and malonic acid as raw materials. Then a novel compound 1,1-bis(1H-benzoimididazole-yl)-1- tridecylene was synthesized via Knoevenagel reaction from lauric aldehyde and bis(1H-benzimidazole-2-yl) methane. The structure of the target compound was characterized by means of elemental analysis, FT-IR and 1H NMR spectra. The effect of conventional base catalysts on the yield of the title compound in Knoevenagel reaction was investigated, and the result indicated that piperidine has the best catalysis effect with a yield 76.33%. UV-Vis, solution fluorescence and solid fluorescence spectroscopy were used to study its photophysics properties. The results showed that the entitle compound has three UV absorption peaks at 243, 315 and 361nm in the dilute solution of ethanol, and a blue-purple fluorescence emission peak at 468nm excited by 360nm. Solid state thin film of the product also emitted a blue-purple fluorescence emission peak at 483.5 nm with a about 20nm red shift compared to the solution fluorescence. The fluorescence quantum yield of the title compound was 0.47. And contrastive tests showed that the fluorescent whitening effect of the title compound is equivalent to that of commercial fluorescent whitening agent VBL.