Voltammetric and impedance study of the binding of ferrocene derivatives to a sulfonated calix[6]arene host in aqueous solutions

Determination of Tryptophan using ap-Sulfonated Calix [4,6,8]arene Modified Gold Electrode

“…Water-soluble calixarenes are important in supramolecular chemistry because they allow the study of the host-guest recognition processes under conditions in which most biological processes occur (Arena et al 2004). In recent years, reports have described the recognition properties of water-soluble p-sulfonated calix[n]arenas (Zhou et al 2005) toward dyes (Yilmaz et al 2007;Akceylan, Bahadir, and Yılmaz 2009), native amino acids (Silva, Shahgaldian, and Coleman 2004;Stone et al 2002), quaternary ammonium ions (Nimse et al 2011;Arena et al 2004;Komura et al 2002), and small molecules (Arena et al 2000). The use of p-sulfonated calix[n]arenas has been investigated for biological and pharmaceutical applications (Millership et al 2001;Silva et al 2004;Gualbert, Shahgaldian, and Coleman 2003).…”

Redox‐Responsive Macroscopic Gel Assembly Based on Discrete Dual Interactions

“…CS6 has a relatively high association constant for the Fc + derivative (K a = 24 10 3 L mol À1 ). [29] CS6 served as a competitive host molecule for Fc + moieties to inhibit the aggregation between the Fc + gel and the SSNa gel. These results indicate that the Fc + gel and the SSNa gel adhered through a cation-anion interaction at the interfaces of the gels (Figure 1 f).…”

Voltammetric study of inclusion of p-sulfonated thiacalix[n]arenes (n=4, 6) toward ferrocenyl guests in aqueous solutions

“…3), suggesting that the inclusion/ejection rates of this system were slower than the CV time scale with scan rate of 0.1 V/s. The slow rate processes of TC6AS-FcCH 2 NMe þ 3 system are contrary to the case of C6AS with FcCH 2 NMe þ 3 and other ferrocenyl guest, showing inclusion equilibria faster than scan rate of 2 V/s [25]. This may be attributed to the larger cavity of TC6AS than that of C6AS, as estimated by the longer C Ar -X bond length [26] and crystallographic structure of p-tert-butylcalix [6]arene (C6A) and TC6A [27,28] to have better shielding ability for accommodated guest from solvent water molecules to form kinetically more stable host-guest complex.…”