Self‐Assembled Monolayer Formed by a Rhenium Complex Containing Hyperbranched Polymer

Abstract

Summary: The synthesis of a hyperbranched polymer containing a rhenium bipyridine complex is reported. The polymer was synthesized from a monomer that contains two chlorotricarbonyl rhenium(I) bipyridine moieties and a stilbazole ligand, and the polymer was formed by the coordination reaction in one single step. Gel permeation chromatography results showed that the resulting polymer had a strong interaction with the column packing material, which was reduced when the eluent was added with an electrolyte. Both atomic force microscopy and laser light scattering showed that the size of the polymer molecules was in the range between 25–30 nm. A monolayer of polymer molecules could form on a pretreated substrate by the self‐assembly process, which can serve as the building block for multilayer ultrathin film devices.The metal‐containing hyperbranched polymer synthesized here.magnified imageThe metal‐containing hyperbranched polymer synthesized here.

Layer‐by‐Layer Deposition of Rhenium‐Containing Hyperbranched Polymers and Fabrication of Photovoltaic Cells

“…[26] It was synthesized by a one-step reaction in which the monomer units were linked together by coordination between the stilbazole ligand and the rhenium center. GPC analysis showed two peaks in the chromatogram, and the high-molecular-weight peak was attributed to the interaction between the charged polymer and the column materials.…”

“…This value agrees with our previous atomic force microscopic (AFM) studies in which the size of the polymer molecules deposited on a silicon wafer was found to be 25-30 nm. [26] Such a large molecular size may be due to the repulsion between charges on different branches in the polymer molecule, which lead to a more extended conformation. In general, r g decreases with the concentration of salt in polyelectrolyte solution due to the screening of charges by the excess counterions added, [34,35] and the presence of salt may also suppress the aggregation of polymer molecules.…”

“…Hyperbranched polymer 1 was synthesized according to a previously published procedure. [26] Sodium poly[2-(3-thienyl)ethoxy-4-butylsulfonate] (PTEBS) was purchased from American Dye Source. Ultrapure water (18.2 MW) was used in the preparation of polymer solutions and in the rinsing of all substrates/polymer films.…”

“…Here, we report the fabrication of multilayer thin films and their photosensitizing properties using a recently reported rhenium complex containing hyperbranched polymer. [26] The polymer can self-assemble on a suitable substrate by electrostatic attraction. To the best of our knowledge, reports on the LBL assembly of dendrimers have been sparse, and most of the work reported is related to dendritic poly(amidoamine) derivatives [27][28][29][30][31] or polyether.…”

Analysis and Isolation of Cationic Rhenium(I) and Ruthenium(II) Multinuclear Complexes Using Size-Exclusion Chromatography

“…Recently, N,N-dimethylformamide and N-methylpyroridone containing KPF6 or NH4PF6 have been used in the GPC analysis of polymers with cationic ruthenium(II) and rhenium(I) complexes. 8,9 However, these solvents are not suitable for preparative chromatography, because their high boiling points make it difficult to remove the solvent. Polar solvents with stable and relatively low boiling points, such as methanol and acetonitrile, should be suitable for more general applications of SEC to multinuclear metal complexes, but they cannot be used as eluents for hydrocarbon-based GPC columns.…”