Tetraethers of calix[4]arenes fixed in the cone conformation and substituted at their wide rim by one to three CMPO residues and hydrogen atoms or t-butyl moieties in the remaining position(s) were synthesized. Liquid/liquid extraction studies of selected lanthanides and actinides were undertaken with these calix[4]arenes, including also a linear trimer, in order to obtain a better understanding for
ipso-Nitration of t-butyl calix[4]arene tetraethers and subsequent hydrogenation provides an easy access to monoamino calix[4]arenes. Reaction with di- and triacid chlorides leads to various double- and triple-calix[4]arenes. With tetra-acid chlorides derived from calix[4]arenes in the cone- or 1,3-alternate-conformations penta-calix[4]arenes are available as molecularly uniform species, which may be regarded as the first generation of calix[4]arene based dendrimers. The structure of the mononitro tetraester derivative, which may serve as a general building block has been confirmed by single crystal X-ray analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.