Ring a bell: Disubstituted calix[4]arene as ligand for transition metal chlorides

Abstract

Lower rim 1,3-disubstituted p-tert-butylcalix [4]arene is studied here in its deprotonated form as complexing ligand for iron and chromium chloride. Crystallization of the two complexes from dry THF gives two different stoichiometries and structures, a trinuclear iron compound and a second, mononuclear structure with chromium. In both cases, the ligand adopts an elliptical shape and the metal ions are bound to the lower rim of the calixarene molecule.

Metallocalix[n]arenes in catalysis: A 13-year update

“…Poor catalytic performances were exhibited by the mixed Fe/Li calix [4]arene compound 63 (Figure 18), recently synthesized by Crochet and Fromm [72]. In fact, the complex proved inactive in the polymerization of styrene and other smaller monomers.…”

“…This was explained considering the absence of accessible coordination sites for the monomer molecules. for clarity [72].…”

Elucidating the role of the o-methoxy group in the lower rim appended salicylideneamine substituents of calix[4]arene ligands on the molecular and electronic structures of dinuclear Fe(iii)-based diamond-core complexes

“…The combination of the classical calix [4]arene (1, Fig. 1) with Fe(III) ions can lead to the generation of mononuclear, 48,49 binuclear, 50 or trinuclear 51 complexes that present an O 6 -coordination environment for the metal centres. Apart from the homometallic species, heterometallic [Ln III 2 -Fe III 2 ] 52 (Ln = Dy, Gd, or Tb) and [M 4 -Fe III 4 ] 53 (M = Na, or K) clusters, which exhibit a sandwich-like motif, can also be generated, and their magnetic or catalytic properties have been documented.…”