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KMID : 1059519920360050669
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Journal of the Korean Chemical Society
1992 Volume.36 No. 5 p.669 ~ p.673
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Complexation of Pyridino-Azacrown Ethers with Alkali Metal Ions in N,N-Dimethylformamide
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Kim Dong-Won
Shin Young-Kook
Kim Chang-Seok
Oh Je-Jik
Jeon Young-Shin
Kim Tae-Seung
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Abstract
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The stability constants, K for the complexation of alkali metal cations(Li+, Na+, K+, Rb+, and Cs+) with both 4,5: 13,14-dibenzo-6,9,12-triaza-bicyclo [15,3,1] heneicosa-1 (21),7,19-trioxa-2,16-dione (DBPDA) and 6,9,12-trioxa-3,15,21-triaza bicyclo [15,3,1] heneicosa-1 (21),17,19-triene-2,16-dione (PDA) in N,N-Dimethylformamide (DMF) were determined conductomatically at various temperatures. At all the experiment temperatures, the K value sequences of the alkali metal ions with DBPDA and PDA are Cs+ > K+ > Rb+ > Li+ > Na+ and Cs+ > K+ > Rb+ > Li+ > Na+, respectively. The K values for DBPDA are larger those of PDA for alkali metal ions. The widely recounted "hole-size-selectivity" principle is not applicable to these complexation systems. From the K values obtained at different temperatures, △H and T△S for these complexation reactions were determined. The enthalpy change plays principal important role in the complex formation by DBPDA. However, in the case of PDA, the entropy change also contributes to its complex formation.
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KEYWORD
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