AI Article Synopsis
- The study investigates the photoexcited triplet state of octaethylaluminum(III)-porphyrin (AlOEP) using advanced magnetic resonance techniques at low temperatures.
- The research highlights the unique properties of AlOEP due to its small ionic radius and six-coordinate structure, exploring how its dynamics compare to those of transition metal porphyrins.
- Findings indicate that temperature-dependent effects, including zero-field splitting and hyperfine coupling, are influenced by dynamic processes related to Jahn-Teller effects, which are important for interpreting EPR data in larger complexes.
Article Abstract
The photoexcited triplet state of octaethylaluminum(III)-porphyrin (AlOEP) was investigated by time-resolved Electron Paramagnetic Resonance, Electron Nuclear Double Resonance and Electron Spin Echo Envelope Modulation in an organic glass at 10 and 80 K. This main group element porphyrin is unusual because the metal has a small ionic radius and is six-coordinate with axial covalent and coordination bonds. It is not known whether triplet state dynamics influence its magnetic resonance properties as has been observed for some transition metal porphyrins. Together with density functional theory modelling, the magnetic resonance data of AlOEP allow the temperature dependence of the zero-field splitting (ZFS) parameters, D and E, and the proton A hyperfine coupling (hfc) tensor components of the methine protons, in the zero-field splitting frame to be determined. The results provide evidence that the ZFS, hfc and spin-lattice relaxation are indeed influenced by the presence of a dynamic process that is discussed in terms of Jahn-Teller dynamic effects. Thus, these effects should be taken into account when interpreting EPR data from larger complexes containing AlOEP.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jmr.2023.107515 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Luminescent Iridium-Terpyridine Complexes with Various Bis-Cyclometalated Ligands.
Molecules
January 2025
Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060, Nishikawatsu, Matsue 690-8504, Shimane, Japan.
A series of luminescent bis-cyclometalated iridium complexes with 2,2':6',2″-terpyridine (tpy), [Ir()(tpy)]PF ( = 2-phenylpyridinate (ppy) for ; benzo[h]quinolinate (bzq) for ; 1-phenylisoquinolinate (piq) for ; and 2-phenylbenzothiazolate (pbt) for ), have been synthesized and structurally characterized. Single-crystal X-ray diffraction analyses reveal that the tpy ligands of - are coordinated to the iridium center in a bidentate fashion, and the uncoordinated pendant pyridine rings in the tpy ligands of - form intramolecular π-π stacking interactions with a phenyl moiety of ligands. In addition, the pendant pyridine ring in the tpy ligand of forms an intramolecular hydrogen bonding interaction, unlike in -.
View Article and Find Full Text PDFSitravatinib in combination with nivolumab plus ipilimumab in patients with advanced clear cell renal cell carcinoma: a phase 1 trial.
Nat Commun
January 2025
Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
We conducted a phase I trial to determine the optimal dose of triplet therapy with the tyrosine kinase inhibitor sitravatinib plus nivolumab plus ipilimumab in 22 previously untreated patients with advanced clear cell renal cell carcinoma. The primary endpoint was safety. Secondary endpoints were objective response rate (ORR), disease control rate (DCR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), 1-year survival probability, and sitravatinib pharmacokinetics.
View Article and Find Full Text PDFTheoretical Understanding of Photoluminescence and Singlet Oxygen Quantum Yields in a Few Halogenated Fluorescein Dyes.
Chem Asian J
December 2024
Department of Chemistry, Indian Institute of Technology Tirupati, Tirupati, A.P 517619, India.
Visible-light absorbing metal-free organic dyes are of increasing demand for various optoelectronic applications because of their great structure-function tunability through chemical means. Several dyes also show huge potential in triplet photosensitization, generating reactive singlet oxygen. Understanding the structure-property relationships of many well-known fluorescein dyes is of paramount importance in designing next-generation energy efficient dyes, which is currently limited.
View Article and Find Full Text PDFDynamics of hydrogen shift reactions between peroxy radicals.
Phys Chem Chem Phys
January 2025
The Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Peroxy radicals are key intermediates in many atmospheric processes. Reactions between such radicals are of particular interest as they can lead to accretion products capable of participating in new particle formation (NPF). These reactions proceed through a tetroxide intermediate, which then decomposes to a complex of two alkoxy radicals and O, with spin conservation dictating that the complex must be formed in the triplet state.
View Article and Find Full Text PDFDynamic Phosphorescence Behavior of Carbene-Metal-Amide Complexes from the Perspective of Excited State Modulation.
Angew Chem Int Ed Engl
January 2025
Beijing Institute of Technology, School of Chemistry and Chemical Engineering, CHINA.
Carbene-metal-amide (CMA) complexes have diverse applications in luminescence, imaging and sensing. In this study, we designed and synthesized a series of CMA complexes, which were subsequently doped into a PMMA host. These materials demonstrate light-induced dynamic phosphorescence, attributed to their long intrinsic triplet state lifetime (τP,int, in the μs-ms scale), high intersystem crossing (ISC) rate constant (kISC, up to 107 s-1), and bright phosphorescence.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!