White-Light Emitting Hydrogen-Bonded Supramolecular Copolymers Based on π-Conjugated Oligomers

Abstract

Three different pi-conjugated oligomers (a blue-emitting oligofluorene, a green-emitting oligo(phenylene vinylene), and a red-emitting perylene bisimide) have been functionalized with self-complementary quadruple hydrogen bonding ureidopyrimidinone (UPy) units at both ends. The molecules self-assemble in solution and in the bulk, forming supramolecular polymers. When mixed together in solution, random noncovalent copolymers are formed that contain all three types of chromophores, resulting in energy transfer upon excitation of the oligofluorene energy donor. At a certain mixing ratio, a white emissive supramolecular polymer can be created in solution. In contrast to their unfunctionalized counterparts, bis-UPy-chromophores can easily be deposited as smooth thin films on surfaces by spin coating. No phase separation is observed in these films, and energy transfer is much more efficient than in solution, giving rise to white fluorescence at much lower ratios of energy acceptor to donor. Light emitting diodes based on these supramolecular polymers have been prepared from all three types of pure materials, yielding blue, green, and red devices, respectively. At appropriate mixing ratios of these three compounds, white electroluminescence is observed. This approach yields a toolbox of molecules that can be easily used to construct pi-conjugated supramolecular polymers with a variety of compositions, high solution viscosities, and tuneable emission colors.

Host–Guest‐Driven Copolymerization of Tetraphosphonate Cavitands

“…The recorded final slope of the curve is comparable to that of ureidopyrimidone-based self-assembling systems reported by Meijer, Schenning et al (slope of 2.48). [21] This result is justi- Table 2. Thermodynamic parameters and K ass values for ITC titration of 2 c with 1 a and 1 c in methanol at 25 8C.…”

Energy transfer processes along a supramolecular chain of π-conjugated molecules

“…By varying x, changes in the average length of the chains are induced, which will in turn influence the energy transfer dynamics from the main chain to the chain ends. Details of the synthesis procedure for the compounds have been given by Dudek et al [21] and Abbel et al [23].…”

Light‐Harvesting Hybrid Assemblies

“…The general approach for the design of white-light-emitting materials involves either the mixing of blue-, green-, and red-emitting, noninteracting chromophores, or by the partial energy transfer between a carefully selected D-A pair. [25] White-light emission has been achieved in PMO hybrids by using an oligo(phenylenevinylene)silane-ruberene donor-acceptor pair (OPV-SiRub, Figure 7). [26] In this case, meso-structured OPV-Si films (mOPV-F) were prepared by placing the OPV-Si precursor on a glass substrate.…”