Synthesis of chiral self-assembling rhombs and their characterization in solution, in the gas phase, and at the liquid-solid interface.
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.
Jeong
Kyung Seok
KS
Department of Chemistry and Division of Molecular Engineering and Chemistry, Korea University, Seoul, 136-701, Korea.
Kim
Sun Young
SY
Shin
Ueon-Sang
US
Kogej
Michael
M
Hai
Nguyen T M
NT
Broekmann
Peter
P
Jeong
Nakcheol
N
Kirchner
Barbara
B
Reiher
Markus
M
Schalley
Christoph A
CA