The Coordination Complexes of Cr(Ⅲ) in [1ChCl∶2EG]/CrCl3·6H2O ILs
ZHANG Xian-jie1, LI Lin-fei1, LI Yan1, 2, LI Jian1, 2*, HUA Yi-xin1, 2, XU Cun-ying1, 2, ZHANG Qi-bo1, 2
1. Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093，China
2. State Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming 650093, China
Abstract：The existing forms of Cr(Ⅲ) complexes in aqueous solution and [1ChCl∶2EG]/CrCl3·6H2O ILs containing 0.1～0.6 mol·L-1 CrCl3·6H2O, respectively, were investigated by using ESI-MS and UV-Vis absorption spectra. The results showed that Cr(Ⅲ) combined with Cl- and H2O to form [Cr(H2O)nCl6-n]n-3 in both cases, and the dominant species of which were affected by the concentration of CrCl3·6H2O. Concretely, the dominant complexes of Cr(Ⅲ) in aqueous solution are [Cr(H2O)6]3+ and [Cr(H2O)5Cl]2+, and the UV-Vis absorption spectra is observed to redshift with an increase in the concentration of CrCl3·6H2O, along with enhancement in the mole fraction of [Cr(H2O)5Cl]2+. By contrast, the dominant species of Cr(Ⅲ) in [1ChCl∶2EG]/CrCl3·6H2O ILs are [Cr(H2O)2Cl4]- and [Cr(H2O)3Cl3]. Increasing the concentration of CrCl3·6H2O results in gradual color change of the solution from light orange-red to dark green, blue shift of the UV-Vis absorption spectra, and higher mole fraction of [Cr(H2O)3Cl3]. Both the coordination number of Cl- and H2O that complexes with Cr(Ⅲ) as well as the relative content of the dominant complexes of Cr(Ⅲ) in solvent is proved to be influenced by variation in the concentration of CrCl3·6H2O.
张贤杰，李林菲，李 艳，李 坚，华一新，徐存英，张启波. [1ChCl∶2EG]/CrCl3·6H2O离子液体中Cr(Ⅲ)配合物的研究[J]. 光谱学与光谱分析, 2018, 38(04): 1225-1230.
ZHANG Xian-jie, LI Lin-fei, LI Yan, LI Jian, HUA Yi-xin, XU Cun-ying, ZHANG Qi-bo. The Coordination Complexes of Cr(Ⅲ) in [1ChCl∶2EG]/CrCl3·6H2O ILs. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(04): 1225-1230.
[1] HU Ru-nan，CHEN Song-qi(胡如南，陈松祺). Useful Deposited Chromium(实用镀铬技术). Beijing：National Defence of Industry Press(北京：国防工业出版社)，2005. 1.
[2] WANG Gui-xiang，ZHANG Xiao-hong(王桂香，张晓红). The Additives and Process for Electroplating(电镀添加剂与电镀工艺). Beijing：Chemical Industry Press(北京：化学工业出版社)，2011. 160.
[3] ZHANG Xing-chen(张星辰). Ionic Liquids-from Theoretical Basis to Research(离子液体—从理论基础到研究进展). Beijing：Chemical Industry Press(北京：化学工业出版社)，2009.
[4] Abbott A P, Capper G, Davies D L, et al. Transactions of the Institute of Metal Finishing, 2004, 82(1-2): 14.
[5] Abbott A P, Al-Barzinjy A A, Abbott P D, et al. Physical Chemistry Chemical Physics, 2014, 16(19): 9047.
[6] Eugénio S, Rangel C M, Vilar R, et al. Thin Solid Films, 2011, 519(6): 1845.
[7] ZHANG Zhi, LI Jian, HUA Yi-xin(张 志, 李 坚, 华一新). Journal of Kunming University of Science and Technology·Natural Science Edition)(昆明理工大学学报·自然科学版), 2013, 38(6).
[8] He X, Zhu Q, Hou B, et al. Surface and Coatings Technology, 2015, 262: 148.
[9] He X, Hou B, Li C, et al. Electrochimica Acta, 2014, 130: 245.
[10] LUO Qin-hui(罗勤慧). Coordination Chemistry(配位化学). Beijing：Science Press(北京：科学出版社)，2012. 89.
[11] Díaz-Moreno S, Mu·oz-Páez A, Martínez J M, et al. Journal of the American Chemical Society, 1996, 118(50): 12654.
[12] Elving P J, Zemel B. Journal of the American Chemical Society, 1957, 79(6): 1281.
[13] Smart D, Such T E. Trans. Inst. Met. Finish., 1983, 61(3): 105.
[14] McCalman D, Sun L, Zhang Y, et al. The Journal of Physical Chemistry B, 2015, 119：6018.
