title: Cooperative thermodynamic control of selectivity in the self-assembly of rare earth metal-ligand helices.
abstract: Metal-selective self-assembly with rare-earth cations is possible with suitable rigid, symmetrical bis-tridentate ligands. Kinetically controlled formation is initially observed, with smaller cations preferentially incorporated. Over time, the more thermodynamically favorable complexes with larger metals are formed. This thermodynamic control is a cooperative supramolecular phenomenon and only occurs upon multiple-metal-based self-assembly: single-metal ML3 analogues do not show reversible selectivity. The selectivity is dependent on small variations in lanthanide ionic radius and occurs despite identical coordination-ligand coordination geometries and minor size differences in the rare-earth metals.
authors.affiliation: Department of Chemistry, University of California-Riverside , Riverside, California 92521, United States.
authors.forename: Amber M
authors.initials: AM
authors.lastname: Johnson
authors.forename: Michael C
authors.initials: MC
authors.lastname: Young
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Julian
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Hooley