title: Heterotopic assemblage of two different disk-shaped ligands through trinuclear silver(I) complexation: ligand exchange-driven molecular motion.
abstract: The sandwich-shaped heterotopic trinuclear Ag+ complex Ag(3)1.2 was exclusively formed from two different tris(thiazolyl) and hexa(thiazolyl) disk-shaped ligands, 1 and 2, with the aid of three Ag+ ions. The variable-temperature 1H NMR study on its complexation behavior revealed that metal-ligand exchanges between the two neighboring thiazolyl nitrogen donors of 2 take place at the three Ag+ centers in concert. DeltaH++ and DeltaS++ for the exchange process were calculated to be 50.5 kJ mol(-1) and -26.7 J mol(-1) K(-1), respectively, and its energy barrier at 298 K was estimated to be 58.5 kJ mol(-1). Each concerted metal-ligand exchange leads to an intramolecular 60 degrees-rotational motion ((P) <==>(M) conversion) between the two disk-shaped ligands.
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Hiraoka
authors.forename: Motoo
authors.initials: M
authors.lastname: Shiro
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Shionoya