Thermodynamics of Calix(4)arene Esters. 1. Complexation of Alkyl p-tert-Butylcalix(4)arenetetraethanoates and Alkali-Metal Cations in Acetonitrile and in Benzonitrile

Abstract

Using silver electrodes a double competition reaction involving cryptands and calixarene esters has been for the first time used for the potentiometric determination of stability constants of highly stable complexes of calixarene esters and metal cations (lithium and sodium) in acetonitrile and in benzonitrile at 298.15 K. Corresponding data for less stable complexes were derived from thermochemical measurements using titration calorimetry (macro and micro). Thus, Gibbs energies, enthalpies, and entropies of complexation of alkyl rings able to enter interaction with neutral species and (ii) a hydrophilic ring able to interact with metal cations. In addition,

An Enchiridion of Supramolecular Thermodynamics: Calix[N]arene (N=4,5,6) Tertiary Amide Derivatives and their Ionic Recognition

“…A similar behaviour has been previously found for other calix [4]arene derivatives. 2,14,15,22 This has been attributed to an interaction of the macrocycle through its hydrophobic cavity with the solvent. Given that this cavity is larger for the cyclic pentamer than for the tetramer, this interaction is expected to be greater for the latter relative to the former.…”

Experimental Evidence for Unusual Protonation of Tetraethyl p-tert-Butylcalix[4]arene Tetraacetate and the Most Probable Structure of the Resulting Complex

“…However, there is evidence that Osubstituted calix [4]arenes can act as hosts for acetonitrile inclusion [21][22][23][24][25][26][27][28][29][30][31][32]. Nevertheless, such host-guest interaction does not appear to interfere with a complexation of ions by the polar groups at the lower rim.…”

Formation of Complexes in RTIL and Ion Separations

“…However, the data that are reported for Ag + seem to be reliable, as the presented by this group value for DMSO fits in very well with the corresponding data of several independent research groups. Some of the logK values for RTILs are presented in Tables 3-5 along with the stability of the same complexes in some molecular solvents (Ruas et al, 2006;Ikeda et al, 2008;Danil de Namor et al, 1995;ArnaudNeu et al, 2003;Bessiere & Lejaille , 1979;Ernst & Jezowska-Trzebiatowska, JezowskaTrzebiatowska & Chmielowska, 1961;Chmielowska, 1961;Kikuchi & Sakamoto, 2000). As could be seen from (Vendilo et al, 2010).…”

“…At the same time, the logK 1 values for an alkali metal cation with crown ether in molecular solvents is correlated (Mei et al, 1977;Smetana & Popov, 1980) with donor number (DN) of the solvent (Reichardt, 2005), Table 5, although some exceptions for [Cs(18C6)] + are known (pyridine: DN 33.1; logK 1 =5.7 (Mei et al, 1977)). In this sense, the log K 1 value presented in (Georg et al, 2010); b (Ruas et al, 2006); c (Ikeda et al, 2008); d logK2 = 3.67 (Ernst &JezowskaTrzebiatowska, 1966) and3.4 (Jezowska-Trzebiatowska &Chmielowska, 1961); e (Lewandowski et al, 2005); f (Bessiere & Lejaille, 1979); j (Danil de Namor et al, 1995); h (Vendilo et al, 2010) ; i (Arnaud-Neu et al, 2003); all data for 23-30 o C. There is also some qualitative agreement of the logK 1 values and a solvent polarity derived from E N T scale (Reichardt, 2005) (empirical scale based on solvatochromic pyridinium Nphenolate betaine dye), Table 5. An examination of Table 5 reveals that the polarity of RTILs with a range of 0.60 -0.65 fits well into the existing empirical solvent polarity scale for molecular solvents characterizing them not as "superpolar", but as quite normal polar solvents (Reichardt, 2005).…”