The synthesis of p-tert-butyl thiacalix[4]arenes functionalized with secondary amide groups at the lower rim and their extraction properties and self-assembly into nanoscale aggregates

In this work, the synthesis of novel p-tert-butyl thiacalix[4]arenes functionalized with the secondary amide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations is described. The ability of novel thiacalixarene derivatives to form dimeric associates held together by hydrogen bonds of p-tert-butyl thiacalixarenes and to recognize metal ions of s (Li+, Na+, K+, Cs+, Mg2+, Ca2+, Ba2+), p (Al3+, Pb2+), and d (Fe3+, Co3+, Ni2+, Cu2+, Ag+, Cd2+, Hg2+) elements was investigated by the picrate extraction method and dynamic light scattering (DLS). As was established, the thiacalix[4]arenes investigated are poor extractants for all the metal ions. Meanwhile they self-associate to form dimers of similar size (1.1–2.7 nm) and nanoscale particles consisting of p-tert-butyl thiacalix[4]arenes and silver cations with hydrodynamic diameters of 70–170 nm.