scholarly journals Building Quantitative Relationships between Ligand Structure and Its Reactivity with Organic Radical Species

2020 ◽  
Author(s):  
Stephen Mezyk ◽  
◽  
Gregory Horne ◽  
Travis Grimes ◽  
Peter Zalupski ◽  
...  
Keyword(s):  
Organic Radical ◽  
Radical Species ◽  
Ligand Structure

scholarly journals Synthesis, Physical Properties, and Reactivity of Stable, π-Conjugated, Carbon-Centered Radicals

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 665 ◽  
Author(s):  
Takashi Kubo
Keyword(s):  
Physical Properties ◽  
Electronic Properties ◽  
Molecular Orbitals ◽  
Organic Radicals ◽  
Organic Radical ◽  
Radical Species ◽  
Magnetic Spin ◽  
Singly Occupied Molecular Orbitals ◽  
Triarylmethyl Radicals

Recently, long-lived, organic radical species have attracted much attention from chemists and material scientists because of their unique electronic properties derived from their magnetic spin and singly occupied molecular orbitals. Most stable and persistent organic radicals are heteroatom-centered radicals, whereas carbon-centered radicals are generally very reactive and therefore have had limited applications. Because the physical properties of carbon-centered radicals depend predominantly on the topology of the π-electron array, the development of new carbon-centered radicals is key to new basic molecular skeletons that promise novel and diverse applications of spin materials. This account summarizes our recent studies on the development of novel carbon-centered radicals, including phenalenyl, fluorenyl, and triarylmethyl radicals.

Nickel Phthalocyanine Complex Encapsulated into Nanopores of Faujasite Zeolite

2006 ◽  
Vol 11-12 ◽  
pp. 281-284 ◽  
Author(s):  
Nayumi Ohata ◽  
Yurie Ito ◽  
Daisuke Gomibuchi ◽  
Hideki Kitamura ◽  
Yasuhiro Funahashi ◽  
...  
Keyword(s):  
Organic Substrate ◽  
Organic Radical ◽  
Spectroscopic Methods ◽  
Homogeneous Reaction ◽  
Radical Species ◽  
X Ray ◽  
Nickel Phthalocyanine ◽  
Phthalocyanine Complex ◽  
Oxidation Reactivity ◽  
Type Zeolite

Nickel(II) phthalocyanine complexes encapsulated in X-type Zeolite were constructed by the ‘Ship-in-bottle’ synthesis, whose characterizations were performed by fluorescent X-ray, UV-vis, reflectance, and ESR spectroscopic methods. UV-vis and Reflectance spectra of NiPc-Na+-X suggested that the Pc ring was synthesized. Solid state ESR spectrum of NiPc-Na+-X gave characteristic pattern for organic radical species. Catalytic oxidation reactivity of the NiPc-Na+-X in homogeneous reaction have been studied for organic substrate in the presence of H2O2.

scholarly journals Quantum chemical calculations for over 200,000 organic radical species and 40,000 associated closed-shell molecules

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Peter C. St. John ◽  
Yanfei Guan ◽  
Yeonjoon Kim ◽  
Brian D. Etz ◽  
Seonah Kim ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Closed Shell ◽  
Organic Radical ◽  
Radical Species

1.1.Improving Radical Persistence through Confinement: A Survey

2021 ◽  
Author(s):  
M. Bertrand ◽  
E. Besson ◽  
S. Gastaldi
Keyword(s):  
Organic Synthesis ◽  
Structural Features ◽  
Organic Radical ◽  
Radical Species ◽  
Tremendous Progress

AbstractMost organic radical species are transient and were long considered to be beyond control. Tremendous progress in the knowledge and understanding of their reactivity has enabled their use as standard intermediates in organic synthesis. In this review, strategies implemented to increase radical lifetimes, without modifying fundamentally their structural features, are presented. A wide array of systems has been designed that allow modulation of the level of confinement constraints. The ability of these systems to increase radical lifetime has now reached the point where a transient radical can become persistent, which opens up many new prospects for future applications.

Electrochemical and spectroelectrochemical properties of nitroxyl radical species in PTMA, an organic radical polymer. Influence of the microstructure

2009 ◽  
Vol 11 (7) ◽  
pp. 1369-1372 ◽  
Author(s):  
Hugo A. López-Peña ◽  
Lindsay S. Hernández-Muñoz ◽  
Judith Cardoso ◽  
Felipe J. González ◽  
Ignacio González ◽  
...  
Keyword(s):  
Nitroxyl Radical ◽  
Organic Radical ◽  
Radical Species ◽  
Spectroelectrochemical Properties

Chiral Organolithium Complexes:  The Effect of Ligand Structure on the Enantioselective Deprotonation of Boc-Pyrrolidine

1996 ◽  
Vol 61 (15) ◽  
pp. 5190-5190
Author(s):  
Donald J. Gallagher ◽  
Shengde Wu ◽  
Nikola A. Nikolic ◽  
Peter Beak
Keyword(s):  
Ligand Structure ◽  
Enantioselective Deprotonation

Development of new magnetic organic conductors based on donor molecules with stable organic radical part

2004 ◽  
Vol 114 ◽  
pp. 533-535 ◽  
Author(s):  
H.-J. Lee ◽  
H.-B. Cui ◽  
H. Fujiwara ◽  
H. Kobayashi ◽  
E. Fujiwara ◽  
...  
Keyword(s):  
Organic Conductors ◽  
Organic Radical

Nitroxyl Modified Tobacco Mosaic Virus as a Metal-Free High-Relaxivity MRI and EPR Active Superoxide Sensor

2018 ◽  
Author(s):  
Madushani Dharmarwardana ◽  
André F. Martins ◽  
Zhuo Chen ◽  
Philip M. Palacios ◽  
Chance M. Nowak ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Single Molecule ◽  
Biological Fluids ◽  
Cellular Respiration ◽  
Organic Radical ◽  
Paramagnetic Resonance ◽  
Metal Free ◽  
Disease States

Superoxide overproduction is known to occur in multiple disease states requiring critical care yet non-invasive detection of superoxide in deep tissue remains a challenge. Herein, we report a metal-free magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) active contrast agent prepared by “click conjugating” paramagnetic organic radical contrast agents (ORCAs) to the surface of tobacco mosaic virus (TMV). While ORCAs are known to be reduced <i>in vivo</i> to an MRI/EPR silent state, their oxidation is facilitated specifically by reactive oxygen species—in particular superoxide—and are largely unaffected by peroxides and molecular oxygen. Unfortunately, single molecule ORCAs typically offer weak MRI contrast. In contrast, our data confirm that the macromolecular ORCA-TMV conjugates show marked enhancement for <i>T<sub>1</sub></i> contrast at low field (<3.0 T), and <i>T<sub>2</sub></i> contrast at high field (9.4 T). Additionally, we demonstrated that the unique topology of TMV allows for “quenchless fluorescent” bimodal probe for concurrent fluorescence and MRI/EPR imaging, which was made possible by exploiting the unique inner and outer surface of the TMV nanoparticle. <a>Finally, we show TMV-ORCAs do not respond to normal cellular respiration, minimizing the likelihood for background, yet still respond to enzymatically produced superoxide in complicated biological fluids like serum.</a>

Supramolecular Enhancement of Aminoxyl ORCA Contrast Agents

2019 ◽  
Author(s):  
Hamilton Lee ◽  
Jenica Lumata ◽  
Michael A. Luzuriaga ◽  
Candace Benjamin ◽  
Olivia Brohlin ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Side Effects ◽  
Magnetic Resonance ◽  
Tobacco Mosaic Virus ◽  
Contrast Agents ◽  
Single Molecule ◽  
Organic Radical ◽  
Resonance Imaging ◽  
Physiological Conditions

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>

Sign in / Sign up

Export Citation Format

Share Document