Analytical Sciences


Abstract − Analytical Sciences, 22(3), 457 (2006).

Complex Formation of p-Nitrocalix[6]arene with Rare Earth Metal Ions
Makiko KAJIWARA, Masayoshi KOGA, Masashi NISHIDA, and Isao YOSHIDA
Department of Applied Chemistry, Faculty of Engineering, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan
p-Nitrocalix[6]arene (CALX-N6, L) formed a 1:1 metal complex, ML, with light rare earth metal ions (M3+), such as La3+, Pr3+ and Nd3+ except Ce3+, but formed a 1:2 (M3+:L) complex, ML2 (the charge of the complex is omitted) with heavy rare earth metal ions, such as Sm3+-Lu3+ including Y3+. The conditional stability constants of these 1:1 and 1:2 complexes, KML and KML2, were measured by a ligand displacement method using absorption spectrophotometry in 4% (v/v) acetone aqueous solution at pH 9.65 ± 0.15 and 25°C.