A series of pyridine complexes are prepared of the general form TpW(NO)(PMe3)(pyr) where pyr is either pyridine or a substituted pyridine. Depending on substitution pattern, the pyridine can be either N- or eta2-coordinated, and the role of the pyridine substituents and metal oxidation state in determining this equilibrium is explored. For eta2-pyridine complexes, the substituent pattern and solubility characteristics also determine the ratio of coordination diastereomers. Rates of both intra- and interfacial linkage isomerizations are explored along with the pyridine rotational barrier. This study is supported by DFT calculations and X-ray data and includes characterization of both eta2-pyridine and eta2-pyridinium complexes.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ja066623f | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Updates on Intrinsic Medicinal Chemistry of 1,4-dihydropyridines, Perspectives on Synthesis and Pharmacokinetics of Novel 1,4-dihydropyrimidines as Calcium Channel Blockers: Clinical Pharmacology.
Curr Top Med Chem
January 2025
Department of Pharmaceutical Chemistry, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSS AHER), Mysuru, Karnataka, India.
Background: Several chemical studies described the physiological efficacy of 1,4- dihydropyridines (DHPs). DHPs bind to specific sites on the α1 subunit of L-type calcium channels, where they demonstrate a more pronounced inhibition of Ca2+ influx in vascular smooth muscle compared to myocardial tissue. This selective inhibition is the basis for their preferential vasodilatory action on peripheral and coronary arteries, a characteristic that underlies their therapeutic utility in managing hypertension and angina.
View Article and Find Full Text PDFSimulation of Ultrafast Excited-State Dynamics in Fe(II) Complexes: Assessment of Electronic Structure Descriptions.
J Chem Theory Comput
January 2025
HUN-REN Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest, Hungary.
Article Synopsis
- The study evaluates different DFT and TD-DFT methods for simulating ultrafast excited-state dynamics in Fe(II) complexes.
- The research uses time-resolved X-ray emission spectroscopy data from specific iron complexes to benchmark simulation results between metal-to-ligand charge-transfer (MLCT) and metal-centered (MC) states.
- Findings suggest that the choice of DFT/TD-DFT method significantly impacts simulation accuracy, with B3LYP* and TPSSh performing best in matching experimental dynamics.
Functionalization of Pyridines at the C4 Position via Metalation and Capture.
Angew Chem Int Ed Engl
January 2025
Texas A&M University, Chemistry, UNITED STATES OF AMERICA.
The functionalization of pyridines at positions remote to the N-atom remains an outstanding problem in organic synthesis. The inherent challenges associated with overriding the influence of the embedded N-atom within pyridines was overcome using n-butylsodium, which provided an avenue to deprotonate and functionalize the C4-position over traditionally observed addition products that are formed with organolithium bases. In this work, we show that freshly generated 4-sodiopyrdines could undergo transition metal free alkylation reactions directly with a variety of primary alkyl halides bearing diverse functional groups.
View Article and Find Full Text PDFVisible-light-induced CO-releasing properties and cytotoxicity of a Ru(II) carbonyl complex containing 2-(pyridin-2-yl)-quinoxaline.
Dalton Trans
January 2025
Department of Chemistry, Faculty of Science, Cairo University, Gamma Street, Giza, Cairo 12613, Egypt.
The photo-induced CO-releasing properties of the dark-stable complex [RuCl(CO)L] (L = 2-(pyridin-2-yl)quinoxaline) were investigated under 468 nm light exposure in the presence and absence of biomolecules such as histidine, calf thymus DNA and hen egg white lysozyme. The CO release kinetics were consistent regardless of the presence of these biomolecules, suggesting that they did not influence the CO release mechanism. The quinoxaline ligand demonstrated exceptional cytotoxicity against human acute monocytic leukemia cells (THP-1), with evidence of potential DNA damage ascertained by comet assay, while it remained non-toxic to normal kidney epithelial cells derived from African green monkey (Vero) cell lines.
View Article and Find Full Text PDFN-Doped Zigzag-Type Aromatic Truncated Cone Belts.
J Am Chem Soc
January 2025
Key Laboratory of Bioorganic Phosphorous and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China.
Zigzag aromatic hydrocarbon belts, ultrashort segments of zigzag carbon nanotubes, have been fascinating in the chemistry community for more than a half century because of their aesthetically appealing molecular nanostructures and tantalizing applications. Precise introduction of heteroatoms of distinct electronegativity and electronic configuration can create various heterocyclic aromatic nanobelts with novel physical and chemical properties. Here, we report the synthesis of unprecedented N-doped zigzag-type aromatic belts, belt[]pyrrole[]pyridines ( = 6-8), from multiple intramolecular C-C homocoupling reactions of readily available azacalix[](3,5-dibromopyridine)s.
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!