synthesis, characterization and fluorescent property evaluation of 1,3,5-triaryl-2-pyrazolines合成、表征及荧光性质的评价1,3,5-triaryl-2-pyrazolines.pdf

Molecules 2011, 16, 7789-7802; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Synthesis, Characterization and Fluorescent Property Evaluation of 1,3,5-Triaryl-2-pyrazolines Aurangzeb Hasan 1,*, Asghar Abbas 2 and Muhammed Nadeem Akhtar 3 1 Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur-50603, Malaysia 2 Department of Chemistry, Faculty of Science, Quaid-i-Azam University, Islamabad 45320, Pakistan 3 Laboratory of Natural Products, Institute of Bioscience, University Putra Malaysia, Kuala Lumpur 43400, Malaysia * Author to whom correspondence should be addressed; E-Mail: flavonoids@; Tel.: +603-7967-5165; Fax: +603-7967-4193. Received: 12 July 2011; in revised form: 3 August 2011 / Accepted: 10 August 2011 / Published: 13 September 2011 Abstract: A series of 1,3,5-triaryl-2-pyrazolines was synthesized by dissolving the corresponding 4-alkoxychalcones in glacial acetic acid containing a few drops of concentrated hydrochloric acid. This step was followed by the addition of (3,4-dimethylphenyl) hydrazaine hydrochloride. Finally the target compounds were precipitated by pouring the reaction mixture onto crushed ice. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The 1,3,5-triaryl-2-pyrazolines bearing homologous alkoxy groups were found to possess fluorescence properties in the blue region o