Highly effective binding of methyl viologen dication and its radical cation by p-sulfonatocalix[4,5]arenes.
The binding behaviors and thermodynamic origins of p-sulfonatocalix[4]arene (C4AS) and p-sulfonatocalix[5]arene (C5AS) with methyl viologen (MV2+) have been investigated by the methods of isothermal titration calorimetry, NMR, and cyclic voltammetry, showing that the binding abilities of C4AS and C5AS and their host selectivity are dramatically pH-controlled, which is closely discussed from the viewpoint of thermodynamics. Moreover, the radical form of MV+* can also be effectively included by C4AS and C5AS.
Guo
Dong-Sheng
DS
Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, People's Republic of China.
Wang
Li-Hua
LH
Liu
Yu
Y
D047250:Calixarenes / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010269:Paraquat / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*