Self-assembly of nanoscale aggregates consisting of p-tert-butylthiacalix[4]arenes tetra-substituted at the lower rim by hydrazide groups, and of metal ions of $p$- and $d$-elements.
Abstract:
New p-tert-butylthiacalix[4]arenes functionalized with hydrazide groups at the lower rim in cone, partial cone and 1,3-alternate conformations were synthesized and their receptor properties for metal ions of $s$- (Li$^+$, Na$^+$, K$^+$, Cs$^+$, Mg$^{2+}$, Ca$^{2+}$, Ba$^{2+})$, $p$- (Al$^{3+}$, Pb$^{2+})$ and $d$- (Fe$^{3+}$, Co$^{3+}$, Ni$^{2+}$, Cu$^{2+}$, Ag$^+$, Cd$^{2+}$, Hg$^{2+})$ elements were studied using the picrate extraction method and dynamic light scattering (DLS). To evaluate the ability of the p-tert-butyl thiacalix[4]arene derivatives to recognize metal ions, liquid-liquid extraction of their picrate salts has been carried out in mutually saturated water-dichloromethane system. The degrees of extraction and the extraction constants for metal cations of $p$- (Al$^{3+}$, Pb$^{2+})$ and $d$- (Fe$^{3+}$, Co$^{3+}$, Ni$^{2+}$, Cu$^{2+}$, Ag$^+$, Cd$^{2+})$ elements have been determined. The ability of the systems consisting of host and guest molecules to self-assembly was proved by means of DLS using Zetasizer Nano ZS particle size analyzer. It was shown that all the investigated thiacalix[4]arenes are able to form nanoscale particles with cations $p$- and $d$-elements under the experiment conditions.