Mixed iridium(III) and ruthenium(II) polypyridyl complexes containing poly(ε‐caprolactone)‐bipyridine macroligands

Abstract

A hydroxy‐functionalized bipyridine ligand was polymerized with ε‐caprolactone utilizing the controlled ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate. The resulting poly(ε‐caprolactone)‐containing bipyridine was characterized by 1H NMR and IR spectroscopy, and gel permeation chromatography, as well as matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, revealing the successful incorporation of the bipyridine ligand into the polymer chain. Coordination to iridium(III) and ruthenium(II) precursor complexes yielded two macroligand complexes, which were characterized by NMR, gel permeation chromatography, matrix‐assisted laser desorption/ionization time‐of‐flight MS, cyclic voltammetry, and differential scanning calorimetry. In addition, both photophysical and electrochemical properties of the metal‐containing polymers proved the formation of a trisruthenium(II) and a trisiridium(III) polypyridyl species, respectively. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4153–4160, 2004

Recent Developments in the Application of Phosphorescent Iridium(III) Complex Systems

“…[87][88][89][90][118][119][120][121][122][123][124][125] One of the earliest examples of an iridium(III)-complex-containing polymer was obtained by Kim and coworkers in a one-pot, two-step complexation reaction; after treating Ir(acac) 3 with 2-phenylpyridine, the ligand-equipped polymer [poly((2-(4-vinylphenyl)pyridine)co-vinylcarbazole)] was added to achieve the formation of polymer-bound tris-cyclometallated Ir III complexes under rather harsh conditions (170 8C for 12 h). [118] Photoluminescence (PL) investigations in solutions pointed to an intermolecular energy transfer between host and guest rather than an intramolecular one.…”

“…To suppress crystallization or aggregation occurring in blended films [86,87] and to enhance the processability (e.g., via inkjetprinting or spin-coating, by inducing film-forming abilities [88] ), cationic Ir III complexes have successfully been introduced into polymeric materials, both non-conjugated [89][90][91] and conjugated ones. [92][93][94][95] In addition to the complexes bearing three bidentate ligands, the analogous compounds containing two tridentate ligands [96] (e.g., 2,2 0 :6 0 ,2 00 -terpyridine, 2,6-diaryl-pyridine, and their derivatives) have recently gained more attention as potential candidates for applications in areas such as luminescent sensors or materials for directional energy and electron transfer.…”

“…While the formation of tris-cyclometallated [118][119][120] and bis-terpyridine iridium(III) complexes [122] are usually rather demanding with respect to temperature and conversion, other types of complexes, e.g., charged bis-cyclometallated complexes bearing bipyridine, can often be obtained in high yields at rather mild conditions. [89,90] Steric demands (e.g., in the case of coordination sites in a conjugated backbone, [119,120] polymer blocks, [121] or crosslinked systems [125] ) is an aspect, which might need to be considered as well. Complex-free polymers are usually easier to investigate by techniques such as SEC, and influences of incorporated complexes are easily revealed by comparing final and precursor polymers.…”

New Trends in the Use of Transition Metal–Ligand Complexes for Applications in Electroluminescent Devices

“…[178] Furthermore, the described reaction schemes were used to synthesize iridium(III) complexes bearing polymer tails such as poly(ethylene oxide), poly(e-caprolactone), or poly(styrene) on the chelating bi-and terpyridine ligands. [179,180] Up to now, these types of complexes have found more interest in the context of biochemical applications such as the labeling of proteins, but recently studies concerning their use in LECs for color-tuning applications have appeared. [134,146] Figure 6.…”

π‐Conjugated Donor and Donor–Acceptor Metallo‐Polymers

“…The usage of Zn II ions leads to metallo-polymers being potential interesting light-emitting materials in OLEDs; [14,15,[21][22][23] moreover, also Ir-containing polymers are of special interest for this purpose. [24][25][26] In recent years, p-conjugated polymer semiconductors with donor-acceptor (D-A) architectures have attracted considerable attention, since their electro-optical properties make them promising candidates for potential applications in the fields of organic electronics. [27][28][29] In this contribution we describe the synthesis and characterization of four metallo-polymers containing either zinc(II) or ruthenium(II) ions in the main chain.…”