title: Tuning of Supramolecular Architectures of l-Valine-Containing Dicyanoplatinum(II) 2,2'-Bipyridine Complexes by Metal-Metal, π-π Stacking, and Hydrogen-Bonding Interactions.
abstract: A series of newly synthesized dicyanoplatinum(II) 2,2'-bipyridine complexes exhibits self-assembly properties in solution after the incorporation of the l-valine amino units appended with various hydrophobic motifs. These l-valine-derived substituents were found to have critical control over the aggregation behaviors of the complexes in the solution state. On one hand, one of the complexes was found to exhibit interesting circularly polarized luminescence (CPL) signals at low temperature due to the formation of chiral spherical aggregates in the temperature-dependent studies. On the other hand, systematic transformation from less uniform aggregates to well-defined fibrous and rod-like structures via Pt⋅⋅⋅Pt and π-π stacking interactions has also been observed in the mixed-solvent studies. These changes were monitored by UV/Vis absorption, emission, circular dichroism (CD), and CPL spectroscopies, and morphologies were studied by electron microscopy.
authors.affiliation: Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee (Hong Kong)) and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Heidi Li-Ki
authors.initials: HL
authors.lastname: Fu
authors.affiliation: Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee (Hong Kong)) and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Po
authors.affiliation: Department of Physics, Hong Kong University of Science of Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Hexiang
authors.initials: H
authors.lastname: He
authors.affiliation: Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee (Hong Kong)) and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Sammual Yu-Lut
authors.initials: SY
authors.lastname: Leung
authors.affiliation: Department of Physics, Hong Kong University of Science of Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Kam Sing
authors.initials: KS
authors.lastname: Wong
authors.affiliation: Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee (Hong Kong)) and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong. wwyam@hku.hk.
authors.forename: Vivian Wing-Wah
authors.initials: VW
authors.lastname: Yam
keywords: bipyridine complexes; intermolecular interactions; l-valine; platinum; self-assembly