Dynamics of Spin-Polarized Radical Pairs at the Solid/Solution Interface

Forbes, Malcolm D. E.; Ruberu, Shiyamalie R.; Dukes, Katerina E.

doi:10.1021/ja00095a038

Cited by 17 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For example, in 1994, Forbes et al reported on a time‐resolved EPR study of organic radicals anchored to silica surfaces to probe their magnetic and kinetic properties at the solution/solid interface. [ 1–3 ] A unique facet of this study was observations of stronger spin polarizations in radical pairs tethered closely to the surface which disappeared in longer tethers, where radical pairs behave similarly to those in free solution. Norrish type I cleavage was used as a means to study the biradicals after decarbonylation and surface phenomena on these silica particles.…”

Section: Introductionmentioning

confidence: 93%

A fluorinated phosphite traps alkoxy radicals photogenerated at the air/solid interface of a nanoparticle

Ghosh

Greer

2020

J of Physical Organic Chem

View full text Add to dashboard Cite

With interests in alkoxy radical formation on natural and artificial surfaces, a physical‐organic study was carried out with a Hammett series of triaryl phosphites (p‐MeO, H, p‐F, and p‐Cl) to trap adsorbed alkoxy radicals on silica nanoparticles. A mechanism which involves PhC (Me)2O• and EtO• trapping in a cumylethyl peroxide sensitized homolysis reaction is consistent with the results. The p‐F phosphite was able to indirectly monitor the alkoxy radical formation, and 31P NMR readily enabled this exploration, but other phosphites of the series such as the p‐MeO phosphite were limited by hydrolysis reactions catalyzed by surface silanol groups. Fluorinated silica nanoparticles helped to suppress the hydrolysis reaction although adventitious water also plays a role in hindering efficient capture of the alkoxy radicals by the phosphite traps.

show abstract

Section: Introductionmentioning

confidence: 93%

A fluorinated phosphite traps alkoxy radicals photogenerated at the air/solid interface of a nanoparticle

Ghosh

Greer

2020

J of Physical Organic Chem

View full text Add to dashboard Cite

show abstract

“…As well as in micelles, APS CIDEP has also been observed in isotropic solution at low temperatures [128], inside the pores of cotton [129,130], for RPs at interfaces [131], in supercritical fluids [132] and for flexible chain-linked biradicals [133] and where extensive use has been made of the ability to determine the exchange interaction from experimental spectra. The above systems have all involved triplet-born RPs, but recently singlet-born RPs have also been observed [134], consisting of two diphenylamino radicals.…”

Section: ·1 Detection By Time-resolved Esr Spectroscopy (Tresr)mentioning

confidence: 99%

Radical Pairs in Solution

Woodward

2002

Progress in Reaction Kinetics and Mechanism

156

101

View full text Add to dashboard Cite

Radical pairs (RPs) are important reaction intermediates generated whenever two radicals encounter one another, a bond is cleaved homolytically or electron transfer between non-radical species takes place. The concept of a radical pair as a reaction intermediate is introduced and developed through simple pictorial analogies, indicating how RP behaviour is governed by interplay of spin and spatial motion. Such analogies are then extended to describe the experimental consequences of RPs in magnetic resonance and magnetochemistry experiments, including reference to the relevance of RPs in biological systems. Finally experimental techniques by which RPs can be observed directly are introduced and described in the context of the developed models.

show abstract

“…We now present an analysis of a polarization mechanism that is characteristic for spin-correlated radical pairs, and which allows a TREPR characterization of these species and so definitively allow them to be differentiated from polarized free radicals. [38,39] …”

Section: Trepr Of Spin-correlated Radical Pairsð Investigation Of Thementioning

confidence: 99%

“…However, the TREPR technique has been employed to investigate all of the important primary photochemical processes of ketones [5] including those producing biradicals. [2,11,38,39] In addition to the photoreactions of ketones, many other organic substrates [1±6, 28, 45, 46] have also been investigated by this technique. The TREPR technique and ESP have also been powerful tools for the investigation of problems particularly of interest in the area of photosynthesis, for example, to provide direct evidence for a specific electron acceptor in photosystem I, [47] and elucidation of donor ± acceptor pairs in the bacterial photosynthetic reaction center.…”

Section: Other Applications Of the Trepr Technique And Espmentioning

confidence: 99%

Electron Spin Polarization and Time-Resolved Electron Paramagnetic Resonance: Applications to the Paradigms of Molecular and Supramolecular Photochemistry

Turro

Kleinman

Karatekin

2000

Angew. Chem. Int. Ed.

View full text Add to dashboard Cite

Most molecular and supramolecular organic photochemical reactions involve paramagnetic reactive intermediates (such as molecular triplet states, triplet radical pairs, and free radicals). In a number of cases these species are created with “anomalous” spin populations which are far from thermal equilibrium. Such paramagnetic species are said to be “spin polarized” and may be observed directly by time‐resolved electron paramagnetic resonance (TREPR). The TREPR technique can be applied to exploit spin polarization, which, in addition to providing an enormous signal to noise enhancement, also reveals the mechanisms involved in photochemical reactions. TREPR spectroscopy provides a means of tracking the reaction of radicals with molecules and the nonreactive interactions of radicals with other radicals in real time. The latter interactions provide a systematic investigation of supramolecular interactions of geminate radicals in micelles.

show abstract

Dynamics of Spin-Polarized Radical Pairs at the Solid/Solution Interface

Cited by 17 publications

References 0 publications

A fluorinated phosphite traps alkoxy radicals photogenerated at the air/solid interface of a nanoparticle

A fluorinated phosphite traps alkoxy radicals photogenerated at the air/solid interface of a nanoparticle

Radical Pairs in Solution

Electron Spin Polarization and Time-Resolved Electron Paramagnetic Resonance: Applications to the Paradigms of Molecular and Supramolecular Photochemistry

Contact Info

Product

Resources

About