Although polycyclic conjugated hydrocarbons (PCHs) and their analogues have gained great progress in the fields of organic photoelectronic materials, the in-depth study on present PCHs is still limited to hexacene or below because longer PCHs are insoluble, unstable, and tediously synthesized. Very recently, various strategies including on-surface synthesis are developed to address these issues and many higher novel PCHs are constructed. Therefore, it is necessary to review these advances. Here, the recent synthetic approach, basic physicochemical properties, single-crystal packing behaviors, and potential applications of the linearly fused PCHs (higher than hexacene), including acenes or π-extended acenes with fused six-membered benzenoid rings and other four-membered, five-membered or even seven-membered and eight-membered fused compounds, are summarized.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7312318 | PMC |
http://dx.doi.org/10.1002/advs.201903766 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.
Expanded heterohelicenes composed of alternating linearly and angularly fused multi-resonance (MR) skeletons have gained wide interest owing to their promising narrowband emissions. Herein, a pair of sym- and asym-expanded heterohelicene isomers was obtained by merging boron/oxygen (B/O)-embedded MR triangulene and indolo[3,2,1-jk]carbazole units via one-pot synthesis. Owing to their fully resonating extended helical skeleton, the target heterohelicenes exhibit a significantly narrowed spectra bandwidth while emission red-shifting, thus affording deep-blue narrowband emission with a peak at approximately 460 nm, full-width-at-half-maximum (FWHM) of only 18 nm, and near-unity photoluminescence quantum yields.
View Article and Find Full Text PDFStat Med
December 2024
Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, Canada.
This work develops a generalized fused lasso (GFL) approach to fitting contrast-based network meta-analysis (NMA) models. The GFL method penalizes all pairwise differences between treatment effects, resulting in the pooling of treatments that are not sufficiently different. This approach offers an intriguing avenue for potentially mitigating biases in treatment rankings and reducing sparsity in networks.
View Article and Find Full Text PDFFront Chem
October 2024
Instituto Universitario de Síntesis Orgánica and Departamento de Química Orgánica, Campus de San Vicente del Raspeig, Universidad de Alicante, Alicante, Spain.
The conductance of a tunneling electron through a π-conjugated molecule may be affected by the presence of different pathways in the orbital structure of the molecule, resulting in the constructive or destructive interference of the molecular wave function. This quantum interference (QI) directly translates into enhancement or suppression of conductance and offers the possibility of controlling this phenomenon through tailored synthesis. Hence, we set up synthetic methodologies to access a series of thiophene-fused helicenes with a well-defined positioning of the sulfur atoms, which control the occurrence of conducting, linearly conjugated as well as disrupted, cross-conjugated pathways.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2024
Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
We measured the temporal voltage response of NbTi superconducting filaments with varied nanoscale thicknesses to step current pulses that induce non-equilibrium superconducting states governed by a hot spot mechanism. Such detected voltage emerges after a delay time td, which is intimately connected to the gap relaxation and heat escape times. By employing time-dependent Ginzburg-Landau theory to link the delay time to the applied current, we determined that the gap relaxation time depends linearly on film thickness, aligning with the acoustic mismatch theory for phonon transmission at the superconductor-substrate interface.
View Article and Find Full Text PDFJ Plast Reconstr Aesthet Surg
December 2024
Department of Surgical Sciences, Plastic surgery, Uppsala University, Uppsala, Sweden.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!