title: Probing a hidden world of molecular self-assembly: concentration-dependent, three-dimensional supramolecular interconversions.
abstract: A terpyridine-based, concentration-dependent, facile self-assembly process is reported, resulting in two three-dimensional metallosupramolecular architectures, a bis-rhombus and a tetrahedron, which are formed using a two-dimensional, planar, tris-terpyridine ligand. The interconversion between these two structures is concentration-dependent: at a concentration higher than 12 mg mL(-1), only a bis-rhombus, composed of eight ligands and 12 Cd(2+) ions, is formed; whereas a self-assembled tetrahedron, composed of four ligands and six Cd(2+) ions, appears upon sufficient dilution of the tris-terpyridine-metal solution. At concentrations less than 0.5 mg mL(-1), only the tetrahedron possessing an S4 symmetry axis is detected; upon attempted isolation, it quantitatively reverts to the bis-rhombus. This observation opens an unexpected door to unusual chemical pathways under high dilution conditions.
authors.affiliation: Departments of †Polymer Science and ‡Chemistry, The University of Akron , 170 University Cr., Akron, Ohio 44325, United States.
authors.forename: Xiaocun
authors.initials: X
authors.lastname: Lu
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Li
authors.forename: Kai
authors.initials: K
authors.lastname: Guo
authors.forename: Ting-Zheng
authors.initials: TZ
authors.lastname: Xie
authors.forename: Charles N
authors.initials: CN
authors.lastname: Moorefield
authors.forename: Chrys
authors.initials: C
authors.lastname: Wesdemiotis
authors.forename: George R
authors.initials: GR
authors.lastname: Newkome