ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Microwave-assisted solvent-free synthesis and luminescence properties of 2-substituted-4,5-di(2-furyl)-1H-imidazoles

Jian Zhang, Tian-Qi Zhao, Yao Chen, Xiao-Dong Chen, Hai-Kun Chang, Yu-Min Zhang, and Shu-Cheng Hua

College of Chemistry, First Hospital, Jilin University, Qianjin Street 2699, Changchun 130012, China

E-mail: zhang_ym@jlu.edu.cn

Abstract: A solvent-free microwave-assisted method for the synthesis of 2-substituted-4,5-di(2-furyl)-1H-imidazoles was developed. Imidazoles with moderate to good yields were produced by condensation of furil with aldehydes over acidic alumina impregnated with ammonium acetate, and they were characterized by FT-IR, HRMS, ¹H NMR and ¹³C NMR spectroscopy. Crystal structure of 2,4,5- tri-2-furyl-1H-imidazole (I ) in the orthorhombic space group Pbca was reported, which showed more coplanarity than the reported crystal structure of I in the monoclinic space group Cc. Moreover, their luminescent properties were investigated. It was found that the organic small molecule compounds synthesized possess higher fluorescence quantum efficiency (up to 0.508) in a 0.1 M H₂SO₄ aqueous solution dissolved in 0.5 mL of CH₃OH; along with higher stability; also the emission of some compounds synthesized in the solution was sensitive to the polarity of the solvents.

Keywords: crystal structure – furil – luminescence property – microwave-assisted – 2-substituted-4,5- di(2-furyl)-1H-imidazole

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0014

Chemical Papers 69 (2) 325–338 (2015)