Abstract
The complexation of several alkyldimethyl(ferrocenylmethyl)ammonium cations, where the alkyl group is -CH3 (1+), -(CH2)6CH3 (2+), or -(CH2)7COOH (3+), by the hosts α- and β-cyclodextrin (α- and β-CD) was investigated in aqueous media using calorimetric and 1H NMR spectroscopic measurements. The calorimetric results indicate that the complexation of all the ferrocene-containing guests is enthalpically driven. β-Cyclodextrin binds all the guests primarily by including the ferrocenyl groups into its cavity. By contrast, α-cyclodextrin binds guests 2+ and 3+ by threading the aliphatic chains of these guests through its cavity. The zwitterionic, deprotonated form (3) of the latter guest is bound by partial inclusion of the ferrocenyl group, a mechanism similar to that prevalent in the complexation of 1+. The complexation processes of 1+ by β-CD and 2+ by α-CD were also investigated in water-urea mixtures. Our calorimetric data reveal that large concentrations of urea cause a substantial decrease in the binding constant for the complexation process. The presence of urea considerably diminishes the enthalpic stabilization of both complexes.
| Original language | English |
|---|---|
| Pages (from-to) | 17449-17455 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry |
| Volume | 99 |
| Issue number | 48 |
| State | Published - Dec 1 1995 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
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Calorimetric studies on the complexation of several ferrocene derivatives by α- and β-cyclodextrin. Effects of urea on the thermodynamic parameters. / Godínez, Luis A.; Patel, Sonal; Criss, Cecil M.; Kaifer, Angel.
In: Journal of Physical Chemistry, Vol. 99, No. 48, 01.12.1995, p. 17449-17455.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Calorimetric studies on the complexation of several ferrocene derivatives by α- and β-cyclodextrin. Effects of urea on the thermodynamic parameters
AU - Godínez, Luis A.
AU - Patel, Sonal
AU - Criss, Cecil M.
AU - Kaifer, Angel
PY - 1995/12/1
Y1 - 1995/12/1
N2 - The complexation of several alkyldimethyl(ferrocenylmethyl)ammonium cations, where the alkyl group is -CH3 (1+), -(CH2)6CH3 (2+), or -(CH2)7COOH (3+), by the hosts α- and β-cyclodextrin (α- and β-CD) was investigated in aqueous media using calorimetric and 1H NMR spectroscopic measurements. The calorimetric results indicate that the complexation of all the ferrocene-containing guests is enthalpically driven. β-Cyclodextrin binds all the guests primarily by including the ferrocenyl groups into its cavity. By contrast, α-cyclodextrin binds guests 2+ and 3+ by threading the aliphatic chains of these guests through its cavity. The zwitterionic, deprotonated form (3) of the latter guest is bound by partial inclusion of the ferrocenyl group, a mechanism similar to that prevalent in the complexation of 1+. The complexation processes of 1+ by β-CD and 2+ by α-CD were also investigated in water-urea mixtures. Our calorimetric data reveal that large concentrations of urea cause a substantial decrease in the binding constant for the complexation process. The presence of urea considerably diminishes the enthalpic stabilization of both complexes.
AB - The complexation of several alkyldimethyl(ferrocenylmethyl)ammonium cations, where the alkyl group is -CH3 (1+), -(CH2)6CH3 (2+), or -(CH2)7COOH (3+), by the hosts α- and β-cyclodextrin (α- and β-CD) was investigated in aqueous media using calorimetric and 1H NMR spectroscopic measurements. The calorimetric results indicate that the complexation of all the ferrocene-containing guests is enthalpically driven. β-Cyclodextrin binds all the guests primarily by including the ferrocenyl groups into its cavity. By contrast, α-cyclodextrin binds guests 2+ and 3+ by threading the aliphatic chains of these guests through its cavity. The zwitterionic, deprotonated form (3) of the latter guest is bound by partial inclusion of the ferrocenyl group, a mechanism similar to that prevalent in the complexation of 1+. The complexation processes of 1+ by β-CD and 2+ by α-CD were also investigated in water-urea mixtures. Our calorimetric data reveal that large concentrations of urea cause a substantial decrease in the binding constant for the complexation process. The presence of urea considerably diminishes the enthalpic stabilization of both complexes.
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UR - http://www.scopus.com/inward/citedby.url?scp=0001085143&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0001085143
VL - 99
SP - 17449
EP - 17455
JO - Journal of Physical Chemistry
JF - Journal of Physical Chemistry
SN - 0022-3654
IS - 48
ER -