Study on Synthesis, Structure Characterization and Fluorescence of Europium Complexes of 2-(4-Fluorobenzoyl) Benzoic Acid
WANG Juan1,GENG Xiao-tian1,LI Zhao-ye1,ZHAO Ying2,WU Hong3,YAN Jian-bo3,WANG Yun-you3,SUN Bo1*
1. Department of Materials Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China 2. State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China 3. China Dankong Industry and Trade Group Company, Taizhou 318000, China
Abstract：The present paper reports three new europium complexes, EuL3(H2O)6,EuL3Phen(H2O)4 and EuL3(TPPO)(H2O)5,synthesized with Eu(NO3)3·6H2O, 2-(4-fluorobenzoyl) benzoic acid, Phen and TPPO(L=2-(4-fluorobenzoyl) benzoic acid, Phen=1,10-phenanthroline, TPPO=triphenyl phosphine oxide). Their composition and chemical structures were characterized by elemental analysis, IR and 1H NMR spectroscopy. The IR spectra indicated that all complexes exhibited the characteristic peaks of carboxylate, asymmetric stretching vibration (νas(CO-2)) and symmetric stretching vibration (νs(CO-2)) peaks; the CO stretching band at 1 692 cm-1 of COOH and the O—H stretching band around 2 500-3 200 cm-1 disappeared. All these complexes had a smaller Δν(νas(CO-2)-νs(CO-2)) value than that of NaL, so the carboxylate groups coordinated with the europium ion in the form of bridging bidentate. In 1HNMR, the signals of hydrogen in 2-(4-fluorobenzoyl) benzoic acid became wide and shifted upfield, and those in Phen, TPPO shifted downfield. The excitation and emission spectra were recorded at room temperature. The excitation spectra showed that the optimum excitation peaks of these three complexes, EuL3(H2O)6,EuL3Phen(H2O)5 and EuL3(TPPO)(H2O)5,were at 353.0, 355.0 and 357.0 nm, respectively. All these three complexes showed Eu3+ ion characteristic emission bands, the electron-dipole transition 5D0→7F2 and magnetism dipole transition 5D0→7F1; their emission peaks were at 596.0，617.0;596.0，619.0;595.0，620.0 nm, and the relative intensities were 1.1，8.6;15.2，100.0;3.6，23.2, respectively. The intensity of 5D0→7F2 was stronger than that of 5D0→7F1,which indicated that europium ions were at asymmetric center. The emission intensities of europium ions were greatly sensitized by Phen.
[1] ZHONG Jin-mao, ZHANG Zheng-hua, BI Ming-liang, et al(钟劲茅，张正华，毕明亮, 等). Chinese Journal of Rare Earth Society(中国稀土学报)，2005, 23(2): 250. [2] Ling Q D, Cai Q J, Kang E T, et al. J. Mater. Chem., 2004, 14：2741. [3] LI Wen-lian(李文连). Chemistry Bulletin(化学通报)，1991, (8): 1. [4] WANG Shao-ting, YANG Yong-li, ZHU Hui-ju, et al(王少亭，杨永丽，朱惠菊，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2006, 26(5): 933. [5] Li H, Inoue S, Machida K，et al. Journal of Luminescence，2000, 87-89: 1069. [6] Hnatejko Z, Elbanowski M. Journal of Alloys and Compounds, 2004, 380: 181. [7] GAO Zhi-hua, WANG Shu-ping, LIU Cui-ge, et al(高志华，王淑萍，刘翠格, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2006, 26(4): 678. [8] Lü Guo-wei, LI Yong, LI Wei-hua, et al(吕国伟，李 勇，李伟华，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2003, 23 (2): 307. [9] LIU Ling, XU Zheng, ZHANG Fu-jun, et al(刘 玲，徐 征，张福俊，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2006, 26(7): 1199. [10] WANG Zheng-xiang, CHEN Hong, TAN Mei-jun, et al(王正祥，陈 洪，谭美军，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2005, 25 (7): 1106. [11] WANG Xi-gui, WU Hong-ying, ZHAO Hui, et al(王喜贵，吴红英，赵 慧，等). Spectroscopy and Spectral Analysis(光谱学与光谱等)，2005, 25(3): 428. [12] BAO Jin-rong, ZHAO Rong-liang, ZHU Xiao-wei (宝金荣，赵永亮，朱晓伟). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2007, 27(3): 539. [13] DAI Li-yan, WU Cai-juan, CHEN Ying-qi, et al(戴立言，吴彩娟，陈英奇，等). Journal of the Chemical Engineering of Chinese Universities(高等学校化学工程学报)，2004, 18(1): 94. [14] ZHAO Yong-liang，ZHAO Feng-ying(赵永亮，赵凤英). Chinese Journal of Rare Earth Society(中国稀土学报)，2001, 19(5): 398. [15] LI Qin, ZHOU De-jian, HUANG Chun-hui, et al(李 琴，周德建，黄春辉，等). Chinese Journal of Rare Earth Society(中国稀土学报)，1997, 15(4): 295. [16] YANG Yong-li, LI Xia, ZONG Rui-fa, et al(杨永丽，李 夏，宗瑞发，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，1997, 17(3): 16. [17] WANG Min, XU Zhi-dong, FENG Dian-zhong(王 敏，徐志栋，冯殿忠). Spectroscopyand Spectral Analysis(光谱学与光谱分析)，1999, 19(3): 484. [18] Dexter D L. J. Chem. Phys., 1953, 21(5): 836. [19] WU Hui-xia, XIN Chi-yang, HE Qi-zhuang, et al(吴惠霞，忻驰洋，何其庄，等). Chinese Journal of Spectroscopy Laboratory(光谱实验室)，2005, 22(2): 260. [20] SU Qiang(苏 锵). Rare Earth Chemistry(稀土化学·第1版). Zhengzhou: Henan Science and Technology Press(郑州: 河南科学技术出版社)，1993. 304.
