title: Synthesis of chiral self-assembling rhombs and their characterization in solution, in the gas phase, and at the liquid-solid interface.
abstract: Chiral, enantiopure metallo-supramolecular rhombs self-assemble in solution through coordination of bis-pyridyl-substituted ligands with (en)M(NO3)2 (en = ethylenediamine, M = Pd(II), Pt(II)). Characterization by NMR and CD spectroscopy in solution and by ESI-FT-ICR mass spectrometry in the gas phase suggests that an equilibrium exists in water/methanol of a major 2:2 complex and a minor 3:3 complex of ligands and metal corners. In the gas phase, doubly charged 2:2 complexes fragment into two identical singly charged halves followed by metal-mediated C-H and C-C bond activation reactions within the ethylenediamine ligands. Electrochemical scanning tunneling microscopy (EC-STM) provides in situ imaging of the complexes even with submolecular resolution. Flat-lying rhombs are deposited under potential control from an aqueous electrolyte on a Cu(100) electrode surface precovered by a tetragonal pattern of chloride anions from the supporting electrolyte. Chirality induces the formation of only one domain orientation. Density functional calculations help to interpret the STM images.
authors.affiliation: Department of Chemistry and Division of Molecular Engineering and Chemistry, Korea University, Seoul, 136-701, Korea.
authors.forename: Kyung Seok
authors.initials: KS
authors.lastname: Jeong
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Ueon-Sang
authors.initials: US
authors.lastname: Shin
authors.forename: Michael
authors.initials: M
authors.lastname: Kogej
authors.forename: Nguyen T M
authors.initials: NT
authors.lastname: Hai
authors.forename: Peter
authors.initials: P
authors.lastname: Broekmann
authors.forename: Nakcheol
authors.initials: N
authors.lastname: Jeong
authors.forename: Barbara
authors.initials: B
authors.lastname: Kirchner
authors.forename: Markus
authors.initials: M
authors.lastname: Reiher
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Schalley