Synthesis And Fluorescence Properties Of Novel Imidazole Derivatives

Recently, supramolecular chemistry and crystal engineering have attracted considerable attention in the research of inorganic chemistry. Through supramolecular forces such as hydrogen bond andπ?πinteraction, many scientists have built some complexes containing novel topological structure. As well as, The potential application in optics, electrics, magnetics and biologic catalytics are studied. Among them, imidazole heterocyclic compounds are a kind of optics materials, illustrating a good prospect of application and extension. Therefore, a series of imidazole derivatives and their fluorescence properties are synthesized and researched. The research is focused on three aspects as follow.Firstly, 1,4-bis(4,5-dihydro-1H-imidazol-2-yl)benzene(bib) and its complexes C12H16N4·2(C7H4NO4) and C12H15N4·C7H6NO2 are synthesized, the complexes are formed through the interaction between bib and 3-nitrobenzoic acid, 4-aminobenzonic acid , respectively. According to the single crystal data, the weak interaction between anions and cations are studied. In the crystal C12H16N4·2(C7H4NO4), the cations and anions are linked through intermolecular N—H…O hydrogen bonds, forming chains running along the a axis. C—H…O interactions also occur. Weakπ?πcontacts between the imidazole rings of bib and between the benzene rings of 3-nitrobenzoic acid [centroid–centroid distances = 3.501 (1) ? and 3.281 (2) (?), respectively] may further stabilize the structure. Moreover, in the crystal C12H15N4·C7H6NO2, the benzene ring makes dihedral angles of 30.51(9)°and 25.64(9)°with the imidazole and imidazolinium rings, respectively. In the crystal, intermolecular N—H…O and N—H…N hydrogen-bonding interactions link the molecules into a three-dimensional network.Secondly, 1,3,5-tris(4,5-dihydro-1H-imidazol-2-yl)benzene(tib) which is the homologue of bib, and its complexes formed by use of the similar method are synthesized. Their structures are confirmed by IR, 1H NMR and ESI-MS. It shows that the experimental results are in accordance with the design.Finally, The fluorescence properties of bib and its complexes are characterized by fluorescent spectra. It shows that the compounds emit stronger fluorescence, whose emission exists at 445 nm. The results show that the imidazole derivatives can be a kind of blue light material, and which is good for further research and development. We realize that imidazole derivatives have distinct fluorescence properties by the research of this task. It is significant for the future study of organic light-emitting materials.