Conformations of calix[4]arenes — an investigation based on CSD data. Part II. Partial cone, 1,2-alternate and 1,3-alternate conformers of methyleneand heteroatom-bridged calix[4]arenes

Abstract

In the first part of this investigation (Part I), cone conformers of calix[4]arenes with methylene and heteroatom bridges from the Cambridge Structural Database (CSD) were investigated. Previously introduced parameters α, β and δ were utilized in describing the conformations of the hydrocarbon base frame of the above mentined compounds. In this part of the investigation, partial cone, 1,2- and 1,3-alternate conformers of methylene- and heteroatom-bridged calix[4]arenes are studied and the influence of inter- and intramolecular interactions on the conformations of these compounds is evaluated.