Single complexation force of 18-crown-6 with ammonium ion evaluated by atomic force microscopy.
The cation complexation force of 18-crown-6 has been measured in ethanol by means of atomic force microscopy using probe tips and mica substrates modified chemically with 18-crown-6 and ammonium ion, respectively. The specific complexation force was suppressed by free potassium ion in the measurement solution, indicating a blocking effect based on the competitive complexation of the 18-crown-6 moiety between the free ion and the ammonium ion bound to the substrate. The single complexation force of 18-crown-6 with ammonium ion was evaluated to be about 60 pN in ethanol by autocorrelation analyses of the histograms for observed forces.
Kado
Shinpei
S
Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, Sakae-dani, Wakayama 640-8510, Japan.
Kimura
Keiichi
K
D043844:Crown Ethers; D004988:Ethers, Cyclic / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*
D043844:Crown Ethers; D004988:Ethers, Cyclic; D000644:Quaternary Ammonium Compounds; C015762:18-crown-6