A Cu\u3csup\u3eI\u3c/sup\u3e-based metallo-supramolecular gel-like material built from a library of oligomeric ligands featuring exotopic 1,10-Phenanthroline units

Abstract

\u3cp\u3eA 22-membered cyclic alkene C\u3csub\u3e1\u3c/sub\u3e incorporating an exotopic 1,10-phenanthroline nucleus in the ring skeleton has been synthesized and subjected to ring-opening metathesis polymerization (ROMP) in dilute dichloromethane solution at varying monomer concentrations (c\u3csub\u3emon\u3c/sub\u3e). The resultant libraries of macrocyclic oligomers were used as ligands for the generation of main-chain metal-ligand oligomeric/polymeric complexes taking advantage of the strong affinity of 1,10-phenanthroline derivatives for Cu\u3csup\u3eI\u3c/sup\u3e. The formation of a gel-like material only upon addition of [Cu(CH\u3csub\u3e3\u3c/sub\u3eCN)\u3csub\u3e4\u3c/sub\u3e]PF\u3csub\u3e6\u3c/sub\u3e to the most concentrated library (c\u3csub\u3emon\u3c/sub\u3e = 60 mM) was explained as arising from the presence of significant amounts of trimeric and higher oligomeric macrocycles C\u3csub\u3ei\u3c/sub\u3e (i ≥ 3), acting as cross-linking components. A gel-like material has been obtained by exo coordination of Cu\u3csup\u3eI\u3c/sup\u3e to the phenanthroline moieties of a library of multitopic cyclic ligands.\u3c/p\u3