三苯基咪唑类化合物的合成及其紫外、荧光性质研究

设计合成了四种三苯基咪唑类化合物:4,5-二苯基-2-对甲酰基苯基咪唑(2a),4,5-二(2-硝基苯基)-2-对甲酰基苯基咪唑(2b),N-苄基-4,5-二苯基-2-对甲酰基苯基咪唑(2c)和N-苄基-4,5-二(2-硝基苯基)-2-对甲酰基苯基咪唑(2d),并用FT-IR,NMR和MS进行结构表征.在乙酸乙酯-石油醚溶液中获得了2c的单晶,用X射线单晶衍射法测定了其晶体结构,晶体属于三斜晶系,空间群P1,晶胞参数a=0.73796(15)nm,b=0.90136(18)nm,c=1.6644(3)nm,α=86.87(3)°,β=78.25(3)°,γ=89.94(3)°,V=1.0822(4)nm3,Dc=1.272g/cm3,Z=2,F(000)=436,μ=0.077mm-1,R1=0.0459,wR2=0.1303.研究了四种化合物的紫外与荧光性质,发现官能团硝基与苄基的引入,对其吸收峰和发射峰均有不同程度的影响:在紫外光谱中两种官能团均使吸收峰蓝移;在荧光光谱中苄基使发射峰蓝移而硝基使发射峰红移.测定了2a和2c在不同溶剂中的荧光寿命,其中2a在DMSO中寿命最长,为3.18ns.这些光谱性质为研究其双光子吸收、双光子荧光和非线性光学性质奠定了理论和实验基础.

Synthesis, Ultraviolet and Fluorescence Properties of Triphenyl Imidazole Com pounds

Four triphenyl imidazole compounds including 4-(4,5-diphenyl-1H-imidazol-2-yl)benzaldehyde (2a), 4-4,5-bis(3-nitrophenyl)-1H-imidazol-2-yl]benzaldehyde (2b), 4-(1-benzyl-4,5-diphenyl-1H-imidazol- 2-yl)benzaldehyde (2c) and 4-1-benzyl-4,5-bis(3-nitrophenyl)-1H-imidazol-2-yl]benzaldehyde (2d) have been synthesized. All the compounds have been identified by FT-IR, NMR and MS techniques. Single crystal of 2c suitable for X-ray measurement was obtained from ethyl acetate/petroleum ether solvent, which belongs to a triclinic system with space group and cell parameters of a＝0.73796(15) nm, b＝0.90136(18) nm, c＝1.6644(3) nm, α＝86.87(3)°, β＝78.25(3)°, γ＝89.94(3)°, V＝1.0822(4) nm³, D_c＝1.272 g/cm³, Z＝2, F(000)＝436, μ＝0,077 mm^－1, R₁＝0.0459, wR₂＝0.1303. Their ultraviolet and fluorescence properties have been studied. The results show that the nitro and benzyl groups influence the absorption and emission spectra of these compounds. The two groups induce blue-shift in the ultraviolet spectra. But in the fluorescence spectra, the benzyl group generates blue-shift while the nitro group causes red-shift. The fluorescence lifetime of 2a and 2c in different solvents has been measured. These results are the base of studying nonlinear optical properties such as two-photon absorption and two-photon fluorescence.