Synthesis And Fluorescence Properties Of 4-Hydroxymethyl Benzimidazole Derivatives

Benzimidazole compounds with fine fluorescence have attracted great attention in recent yearsbecause of good N/O coordination capability with many metal ions for detecting in the environment. In thispaper, fluorescent derivatives of （¹H-benzo[d]imidazol-4-yl） methanol were synthesized. Methylol groupwas added to these compounds compared with ¹H-benzo[d]imidazole, so the coordination capability waschanged. Target compounds were charactered by¹H-NMR, UV and FL. The paper mainly consists of belowparts:In the first part, a brief introduction of basic property of fluorescence and fluorescent probe and studyprogress of fluorescent probe included derivatives of 2-（¹H-benzo[d]imidazol-2 -yl）phenol for metalliccations are provided.In the second part, （2, 3-diaminophenyl） methanol as important intermediate was synthesized withgood route from o-toluidine. Then a series of target compounds were designed and synthesized and theirmolecular structures confirmed by¹H-NMR.The third part is about UV and fluorescent spectroscopy of end compounds. Compounds A, C, D，Eand F have large stoke’s shift, compounds A, B, D, and E have good fluorescence quantum yields on thebasis of quinine sulfate. The coordination study between target compounds and lots of ions, such as Mg²⁺、Ca²⁺、Na⁺、K⁺、Sn²⁺、Cd²⁺、Mn²⁺、Co²⁺、Al³⁺、Zn²⁺、Fe³⁺、Cu²⁺, and the fluorescent spectra changeare discussed. The results show that A has selectivity to Al³⁺and Zn²⁺, the fluorescent emission wavelengthchange obviously, the detectability were 9.0×10^-6mol L^-1and 5.8×10^-6mol L^-1. The coordination of D and Ewith Zn²⁺also can influence the fluorescent spectra with the detectability of 4.0×10^-6mol L^-1、2.8×10^-6mol L^-1. The actual experimental data indicate the feasibility of compounds A, D, E as fluorescentprobe.