Determination of inclusion complex formation constants for the β-CD and [Cu(Dien)(sub-Py)]2+ ion by the spectrophotometric methods
Analytical Science and Technology / Analytical Science and Technology, (P)1225-0163; (E)2288-8985
2007, v.20 no.5, pp.406-412
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(2007). Determination of inclusion complex formation constants for the β-CD and [Cu(Dien)(sub-Py)]<sup>2+</sup> ion by the spectrophotometric methods. , 20(5), 406-412.
Abstract
The formation of inclusion complexes between ${\beta}$-cyclodextrin and diethylenetriamine substituted-pyridine copper(II) perchlorate; [Cu(dien)(sub-py)] $(ClO_4)_2$, were studied by spectrophotometric methods. On account of charge-transfer band(MLCT) and $^2T_2{\rightarrow}^2E$, the two high peaks were observed as an inclusion complex for the [${\beta}$-CD]$[Cu(dien)(p-Cl-py)]^{2+}$ in the ultraviolet region of the spectrum. The ${\beta}$-CD and $[Cu(dien)(sub-py)]^{2+}$ ion formed a 1:1 complex, and the formation constants were decreased with the increasing temperatures, due to weak binding energy between ${\beta}$-CD and $[Cu(dien)(sub-py)]^{2+}$ ion. This reaction was controlled by enthalpy. In a correlation of the Hammett substituent constants and formation constants for the reaction, formation constants were increased by strong binding energy in the inclusion complexes when electron donating groups were substituted in pyridine ring.
- keywords
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<TEX>${\beta}$</TEX>-CD,
<TEX>$[Cu(dien)(sub-py)]^{2+}$</TEX>,
inclusion complex,
Hammett constant