Journal of Zhejiang University SCIENCE
(ISSN 1009-3095, Monthly)

2005   Vol. 6B   No. 1   p.69-73

Microcalorimetric study on host-guest complexation of naphtho-15-crown-5 with four ions of alkaline earth metal

SONG Ming-zhi, ZHU Lan-ying, GAO Xi-ke, DOU Jian-min, SUN De-zhi^*

(Department of Chemistry, Liaocheng University, Liaocheng 252059, China)
^*E-mail: sundezhisdz@163.com
Received Mar. 30, 2004; revision accepted Apr. 27, 2004

Abstract: Thermodynamic parameters of complexation of naphto-15-crown-5 with four alkaline earth ions in aqueous media was determined using titration microcalorimetry at 298.15 K. The stability of the complexes, thermal effect and entropy effect of the complexation is discussed on the basis of the guest ions structure and the solvent effect. The stability constants tendency to vary with ion radius was interpreted. Complex of naphtha-15-crown-5 with calcium ion is very stable due to the synergism of static electric interaction and size selectivity between the host and the guest.

Key words: Microcalorimetry, Host-guest complexation, Naphtho-15-crown-5, Alkaline earth metal, Molecular recognition
doi:10.1631/jzus.2005.B0069             CLC number: O642