Synthesis and Properties of a Novel Through-Space Conjugated Polymer with [2.2]Paracyclophane and Ferrocene in the Main Chain

A highly stable, Au/Ru heterobimetallic photoredox catalyst with a [2.2]paracyclophane backbone

We report the synthesis and catalytic application of a highly stable distance-defined Au/Ru heterobimetallic complex. [2.2]Paracyclophane serves as a backbone, holding the two metal centers in a spatial orientation and metal-metal fixed distance. The Au/Ru heterobimetallic complex is highly stable, easily accessible and exhibits promising catalytic activity in a visible-light mediated dual Au/Ru Meyer-Schuster rearrangement.

Through-space π-delocalization in a conjugated macrocycle consisting of [2.2]paracyclophane

Herein, we report the synthesis and characterization of a [2.2]paracyclophane-containing macrocycle (PCMC) as a new through-space conjugated macrocycle using only benzene groups as the skeleton. For comparison, a diphenylmethane-containing nanohoop macrocycle (DCMC) with a non-conjugated linker was also synthesized. Their structures were confirmed by NMR and HR-MS, and their photophysical properties were studied by UV-vis and fluorescence spectroscopies combined with theoretical calculations. The strain energy of PCMC was estimated to be as high as 72.58 kcal mol-1.

Synthesis and photophysical studies of through-space conjugated [2.2]paracyclophane-based naphthalene fluorophores

New three-dimensional compact organic fluorophores with tunable photophysical properties are easily accessible from [2.2]paracyclophane using an intramolecular dehydrogenative Diels–Alder reaction as a key step.

Vice versa donor acceptor fluorene–ferrocene alternate copolymer: a twisted ribbon for electrical switching

Two donor–acceptor type copolymers (PFFC-1 and PFFC-2) containing ferrocene and fluorene moieties have been successfully synthesized to evaluate the redox triggered optical and electronic properties.

Recent Progress on the Photonic Properties of Conjugated Organometallic Polymers Built Upon the trans-Bis(para-ethynylbenzene)bis(phosphine)platinum(II) Chromophore and Related Derivatives

This review article surveys the electronic and photophysical properties of conjugated organometallic polymers built upon the title compound and its related derivatives focussing primarily on systems investigated in our laboratories. The general structure of the polymers is (trans-bis(para-ethynylbenzene)bis(phosphine)platinum(II)-G)(n) where G is a conjugated group such as thiophene, fluorene, carbazole, substituted silole, quinone derivative, and metalloporphyrin residue, or a non-conjugated main-group moiety. Systems based on substituted phenylene units and other related fused rings are also discussed. The phosphine ligands are generally triethyl- or tri-n-butylphosphine groups. These trans-platinum(II) polymers and the corresponding model compounds are compared to the corresponding ortho-derivatives in the quinone series, and the newly prepared paracyclophane-containing polymers. For the porphyrin series, a comparison of fully conjugated oligomers exhibiting the general structure (trans-bis(para-ethynyl(zinc(porphyrin)))bis(phosphine)platinum(II))(n) (i.e., the C(6) H(4) group is absent from the main chain) will be made. This contribution also includes a description of the properties of the mononuclear chromophore itself, properties that define those of the polymers. Potential applications with regard to electronic and optical devices will be highlighted. These soluble and stable materials feature both the processing advantages of polymers and the functionality provided by the presence of metal centers. These multifunctional organometallic polyyne polymers exhibit convenient structural variability as well as optical and electronic properties, which renders them important for use in different research domains as chemical sensors and sensor protectors, as converters for light/electricity signals, and as patternable precursors to magnetic metal alloy nanoparticles.

New Type of Donor-Acceptor Through-Space Conjugated Polymer

We report the synthesis and properties of a novel through-space conjugated polymer with a [2.2]paracyclophane skeleton. The obtained polymer possessed donor (fluorene) and acceptor (2,1,3-benzothiadiazole) segments that were alternatelyπ-stacked in proximity via the [2.2]paracyclophane moieties. The good overlap between the emission peak of the donor unit (fluorene) and the CT band of the acceptor unit (2,1,3-benzothiadiazole) caused fluorescence resonance energy transfer, and the visible green light emission from the acceptor unit was observed.

Efficient electron delocalization mediated by aromatic homoconjugation in 7,7-diphenylnorbornane derivatives

Efficient electron delocalization by aromatic homoconjugated 7,7-diphenylnorbornane (DPN) in alternated homoconjugated-conjugated block copolymers and reference compounds is revealed by photophysical and electrochemical measurements. The synthesis of the polymers was achieved by Suzuki polycondensation reaction. Effective electron delocalization by DPN is demonstrated by the significant red shifts observed in the absorption and emission spectra and the variation of the energy band gap of the polymers and monomeric model compounds in comparison to a series of oligophenylenes used as references (p-quaterphenyl, p-terphenyl, and biphenyl). The electron delocalization is also clearly demonstrated by the lower oxidation potential measured for homoconjugated model compound in comparison to p-terphenyl. The results show that the electron delocalization caused by two homoconjugated aryl rings is comparable to the effect produced by one conjugated aryl ring.

Ultrafast excited-state dynamics of phenyleneethynylene oligomers in solution

The excited-state dynamics of oligomeric phenyleneethynylenes (OPEs) of various length and substitution has been investigated by femtosecond time-resolved spectroscopy. The fluorescence lifetime of the OPEs decreases with the number of phenyleneethynylene units up to about 9. This effect is due to an increase of the oscillator strength for the S(1)-S(0) transition. Dynamic features occurring within a few tens of picoseconds and ascribed to structural relaxation directly after population of the S(1) state can be observed in non-viscous solvents. The effect of torsional disorder on the fluorescence intensity is shown to depend strongly on the nature of the substituent on the phenyl groups. All these effects are qualitatively discussed with a simple exciton model.

Through-Space Conjugated Polymers Based on Cyclophanes

Conjugated polymers display unique electronic and optical properties, which favor their use in applications as optoelectronic materials and molecular devices. Despite the recent remarkable progress in the chemistry of conjugated polymers, the synthesis of conjugated polymers containing cyclophane units in the main chain is limited to only a few examples. This Minireview presents recent developments in the synthesis, properties, and applications of through-space conjugated polymers based on cyclophanes.