Ma Hui Li, Jin Wei Jun, Xi Lei, Dong Zhong Jie
Shanxi Vocational Poly-tech College, Taiyuan 030006, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Oct 1;74(2):502-8. doi: 10.1016/j.saa.2009.06.057. Epub 2009 Jul 8.
The solvation and protonation of the meso-tetrakis(p-sulfonatophenyl)porphyrin (TPPS) were investigated by spectroscopic methods in pure or mixed imidazolium-based ionic liquids: 1-butyl-3-methyl-imidazolium terafluoroborate ([MBIM]BF(4)), 1-butylimidazolium terafluoroborate ([HBIM]BF(4)), 1-butyl-imidazolium dodecylalkylbenzenesulfonate ([HBIM]DS), 1-butyl-imidazolium p-toluenesulfonate ([HBIM]TS) and 1-butyl-imidazolium methylsulfonate ([HBIM]MS). Compared with absorption properties of TPPS in aqueous solution, Soret band of TPPS monomer was obviously red-shifted in the ionic liquids, while special absorption of TPPS J-aggregates was located at higher energy level, 483 nm and 702 nm, in protonic ionic liquids (PILs) [HBIM]BF(4). Next, the protonation of TPPS in aprotonic ionic liquids (AILs, i.e., [MBIM]BF(4)) is dependent not only on the concentration of protonic ionic liquids as proton sources, but also on the characteristic of anion and viscosity of PILs. The proton transfer constants between TPPS and four protonic ionic liquids are (2.32 +/- 0.23) x 10(2) for [HBIM]BF(4), (1.52 +/- 0.08) x 10(2) for [HBIM]MS, (1.12 +/- 0.21) x 10(2) for [HBIM]DS and (0.84 +/- 0.45) x 10(2) for [HBIM]TS, respectively.
采用光谱法研究了中位-四(对磺酸钠苯基)卟啉(TPPS)在纯的或混合的咪唑基离子液体中的溶剂化和质子化行为，这些离子液体包括：1-丁基-3-甲基咪唑四氟硼酸盐([MBIM]BF₄)、1-丁基咪唑四氟硼酸盐([HBIM]BF₄)、1-丁基咪唑十二烷基苯磺酸盐([HBIM]DS)、1-丁基咪唑对甲苯磺酸盐([HBIM]TS)和1-丁基咪唑甲磺酸盐([HBIM]MS)。与TPPS在水溶液中的吸收特性相比，TPPS单体的Soret带在离子液体中明显红移，而TPPS J-聚集体的特征吸收在质子型离子液体(PILs)[HBIM]BF₄中位于较高能级，分别为483 nm和702 nm。其次，TPPS在非质子型离子液体(AILs，即[MBIM]BF₄)中的质子化不仅取决于作为质子源的质子型离子液体的浓度，还取决于PILs的阴离子特性和粘度。TPPS与四种质子型离子液体之间的质子转移常数分别为：[HBIM]BF₄为(2.32±0.23)×10²、[HBIM]MS为(1.52±0.08)×10²、[HBIM]DS为(1.12±0.21)×10²、[HBIM]TS为(0.84±0.45)×10²。
