Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
Understanding the electronic structure of polycyclic aromatic compounds is of fundamental importance for their potential applications. The optoelectronic properties of shorter acenes such as tetracene and pentacene have been extensively studied with regard to excitation, emission, and nonlinear effects such as singlet fission. The longer homologues present a unique challenge due to their low stability both in the solid state and in solution. In this work, we synthesized persistent 6,8,15,17-tetrakis((triisopropylsilyl)ethynyl)heptacene and investigated its photophysical properties as well as those of the parent heptacene. Our steady-state electronic absorption and emission experiments combined with transient absorption spectroscopy show that the Franck-Condon electric-dipole-forbidden ("dark") transition to the 2A singlet state is the lowest-energy excited state of heptacene. This contrasts with the optical properties of the well-known shorter acenes. Transient absorption data further suggest singlet fission or intersystem crossing as potential pathways to rapid population of the triplet state facilitated by the dark singlet state.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.5c01314 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Excitatory glycine receptors control ventral hippocampus synaptic plasticity and anxiety-related behaviors.
Proc Natl Acad Sci U S A
September 2025
Institut de Biologie de l'Ecole Normale Supérieure, Ecole Normale Supérieure, Université Paris Sciences et Lettres, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris 75005, France.
Excitatory glycine receptors (eGlyRs), composed of the glycine-binding NMDA receptor subunits GluN1 and GluN3A, have recently emerged as a novel neuronal signaling modality that challenges the traditional view of glycine as an inhibitory neurotransmitter. Unlike conventional GluN1/GluN2 NMDARs, the distribution and role of eGlyRs remain poorly understood. Here, we show that eGlyRs are highly enriched in the ventral hippocampus (VH) and confer distinct properties on this brain region.
View Article and Find Full Text PDFQuinoline as a Photochemical Toolbox: From Substrate to Catalyst and Beyond.
Acc Chem Res
September 2025
Department of Chemistry, FRQNT Centre for Green Chemistry and Catalysis, McGill University, 801 Sherbrooke Street W, Montréal, Québec H3A 0B8, Canada.
ConspectusMolecular photochemistry, by harnessing the excited states of organic molecules, provides a platform fundamentally distinct from thermochemistry for generating reactive open-shell or spin-active species under mild conditions. Among its diverse applications, the resurgence of the Minisci-type reaction, a transformation historically reliant on thermally initiated radical conditions, has been fueled by modern photochemical strategies with improved efficiency and selectivity. Consequently, the photochemical Minisci-type reaction ranks among the most enabling methods for C()-H functionalizations of heteroarenes, which are of particular significance in medicinal chemistry for the rapid diversification of bioactive scaffolds.
View Article and Find Full Text PDFAn optimized C single-quantum CPMG relaxation dispersion experiment for investigating microsecond-to-millisecond timescale dynamics in large proteins.
J Biomol NMR
September 2025
Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
Biomolecular dynamics in the microsecond-to-millisecond (µs-ms) timescale are linked to various biological functions, such as enzyme catalysis, allosteric regulation, and ligand recognition. In solution state NMR, Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments are commonly used to probe µs-ms timescale motions, providing detailed kinetic, thermodynamic, and mechanistic information at the atomic level. For investigating conformational dynamics in high-molecular-weight biomolecules, methyl groups serve as ideal probes due to their favorable relaxation properties, and C CPMG relaxation dispersion is widely employed for characterizing dynamics in selectively CH-labeled samples.
View Article and Find Full Text PDFCollisional Excitation of HCN by CO to Refine the Modeling of Cometary Comae.
J Phys Chem A
September 2025
Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251, Rennes F-35000, France.
We present the first dataset of collisional (de)-excitation rate coefficients of HCN induced by CO, one of the main perturbing gases in cometary atmospheres. The dataset spans the temperature range of 5-50 K. It includes both state-to-state rate coefficients involving the lowest ten and nine rotational levels of HCN and CO, respectively, and the so-called "thermalized" rate coefficients over the rotational population of CO at each kinetic temperature.
View Article and Find Full Text PDFEffect of Oxygen Exposure on the Triplet Excitation Dynamics of the Monomeric LHCII Complex from Spinach.
J Phys Chem B
September 2025
Key Laboratory of Advanced Light Conversion Materials and Biophotonics, School of Chemistry and Life Resources, Renmin University of China, Beijing 100872, China.
Light-harvesting complex IIs (LHCIIs) are the major antenna in higher plants, balancing light capture through photoprotection. While it naturally forms trimers, stress conditions can induce monomerization, altering pigment interactions. Here, we explored how molecular oxygen affects triplet excited-state dynamics in LHCII monomers using time-resolved transient absorption spectroscopy under aerobic and anaerobic conditions.
View Article and Find Full Text PDF