What's your role? New oligothiophene-vinylene compounds have been synthesized to study the role of the conjugated chain in two different cases (see scheme; MV=mixed valence). The electronic and molecular structures were analyzed by means of electronic, X-ray photoelectron, and Raman spectroscopy, together with thermo spectroscopy, electrochemistry, and DFT calculations.New oligothiophene-vinylene compounds have been synthesized in order to study the role of the conjugated chain in two different cases: 1) when push-pull action operates between an electron-donor and an electron-acceptor group at the ends of the thiophene-vinylene conjugated chain, and 2) when mixed-valence action is induced by single oxidation of the same chain functionalized at both terminal positions with ferrocene groups leading to competition between the donor groups. The electronic and molecular structures are analyzed by means of electronic, X-ray photoelectron and Raman spectroscopies, together with thermospectroscopy, electrochemistry and density functional theory calculations. The cyclic voltammetry processes have been followed by spectrochemistry. It is shown that the radical cation of the diferrocenyl derivative is a class III mixed-valence system (i.e., fully delocalized) according to its Raman spectrum. Moreover, by Raman thermo-spectroscopy the thermal transition of this radical cation from a delocalized (class III, room temperature) to a localized (class II, -160 degrees C) state is scanned. In all cases the Raman study is paralleled by an electronic absorption spectroscopic analysis. Structure-property relationships are proposed for molecules of two important fields of very active research as that of the non-linear optics (i.e., organic optoelectronic) and that of the mixed-valence systems (i.e., charge-transfer processes).
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.200801589 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
Department of Physics and Centre for Processable Electronics, Imperial College London, SW7 2AZ, London, United Kingdom.
Conjugated polymers (CPs) with polar side chains can conduct electronic and ionic charges simultaneously, making them promising for bioelectronics, electrocatalysis and energy storage. Recent work showed that adding alkyl spacers between CP backbones and polar side chains improved electronic charge carrier mobility, reduced swelling and enhanced stability, without compromising ion transport. However, how alkyl spacers impact polymer backbone conformation and, subsequently, electronic properties remain unclear.
View Article and Find Full Text PDFAdv Mater
December 2024
Department of Diagnostic Radiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119074, Singapore.
The unprecedented success of mRNA vaccines against COVID-19 has inspired scientists to develop mRNA vaccines for cancer immunotherapy. However, using nucleoside modified mRNA as vaccine, though evading innate immune toxicity, diminishes its therapeutic efficacy for cancers. Here, we report a polyvalent stimulator of interferon genes (STING) activating polymer (termed as PD) to bolster the immunogenicity of mRNA vaccine.
View Article and Find Full Text PDFJ Pediatric Infect Dis Soc
December 2024
Arctic Investigations Program, Centers for Disease Control and Prevention, Anchorage, Alaska, U.S.A.
We used polymerase chain reaction (PCR) to identify bacterial infections in culture-negative pleural fluid specimens from Alaska Native children hospitalized with empyema. PCR identified ≥1 organism in 11 (79%) of 14 specimens. Streptococcus pneumoniae serotype 3 was detected in six specimens; all six participants had received 13-valent pneumococcal conjugate vaccine.
View Article and Find Full Text PDFAdv Mater
December 2024
State Key Laboratory of Polymer Physics and Chemistry & Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
The charge transport of channel materials in n-type organic electrochemical transistors (OECTs) is greatly limited by the adverse effects of electrochemical doping, posing a long-standing puzzle for the community. Herein, an n-type conjugated polymer with glycolated side chains (n-PT3) is introduced. This polymer can adapt to electrochemical doping and create more organized nanostructures, mitigating the adverse effects of electrochemical doping.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, United States.
The short-chain (C to C) and ultrashort-chain (C to C) per- and polyfluoroalkyl substances (PFAS) are bioaccumulative, carcinogenic to humans, and harder to remove using current technologies, which are often detected in drinking and environmental water samples. Herein, we report the development of nonafluorobutanesulfonyl (NFBS) and polyethylene-imine (PEI)-conjugated FeO magnetic nanoparticle-based magnetic nanoadsorbents and demonstrated that the novel adsorbent has the capability for highly efficient removal of six different short- and ultrashort-chain PFAS from drinking and environmental water samples. Reported experimental data indicates that by capitalizing the cooperative hydrophobic, fluorophilic, and electrostatic interaction processes, NFBS-PEI-conjugated magnetic nanoadsorbents can remove ∼100% short-chain perfluorobutanesulfonic acid within 30 min from the water sample with a maximum absorption capacity of ∼234 mg g.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!