Magnetic resonance studies of some low-spin d5 tris diimine complexes

DeSimone, Richard E.; Drago, Russell S.

doi:10.1021/ja00711a025

Cited by 165 publications

(138 citation statements)

References 0 publications

Supporting

Mentioning

126

Contrasting

Unclassified

Order By: Relevance

“…The actual value of 'Cs used in the fits shown in Figures 2 and 3 and the k bet values following from the above mentioned condition are given in Tables 2 and 3. The "s values obtained range between 8 and 21 ps and are in general agreement with NMR data for comparable Ru 3 +-complexes. For example a constant value of20 ps was evaluated by Doddrell et al [5] for Ru(acach in a field range from 0.2 to 6 T. More specifically, our linewidth analysis of the 'H-NMR spectra of Ru(bpyH+ and Ru(phen)j+ published by DeSimone and Drago [17] revealed that electron spin relaxation in the latter is about twice as fast as in the former, in fair accord with our magnetokinetic finding.…”

Section: Resultssupporting

confidence: 89%

Magnetokinetic Probing of Extremely Fast Electron Spin Relaxation in Paramagnetic Ruthenium Complexes*

Bürßner¹,

Wolff²,

Steiner³

1993

Zeitschrift Für Physikalische Chemie

View full text Add to dashboard Cite

Magnetic field effects I Paramagnetic relaxation I Magnetokinetics I Photo electron transfer I Spin chemistryA regularity previously observed in the ligand dependence of the magnetokinetic effect on the photoelectron transfer efficiency between photoexcited bileptic Ru-trisdiimine complexes and methylviologen has been substantiated by investigating, in addition, the bipyridine/phenanthroline series of ligands. Our theoretical model of the mechanism has been improved by taking into account non-rotational mechanisms of spin relaxation in the photooxidized Ru 3 + -complex. The field dependences observed for the two bileptic series of complexes can be theoretically reproduced in a very consistent way. Paramagnetic relaxation times found to range around 10 -11 s, reveal a striking regularity in the course of ligand variation through the bileptic series.Eine kiirzlich beobachtete RegelmiiJ3igkeit in der Ligandenabhiingigkeit des magnetokinetischen Effekts auf die Effizienz des Photoelektronentransfers zwischen photoangeregten bileptischen Ru-trisdiimin Komplexen und Methylviologen wurde an einem weiteren Beispiel, Komplexen mit der Bipyridin/Phenanthrolin Ligandenreihe, bestiitigt. Unser Modell zur theoretischen Beschreibung der Magnetfeldabhiingigkeit wurde verbessert, indem es nun auch rotationsunabhiingige Mechanismen der Spinrelaxation im photooxidierten Ru 3 + -Komplex beriicksichtigt. Die fUr die beiden bileptischen Komplexserien beobachteten Feldabhiingigkeiten k6nnen theoretisch in sehr konsistenter Weise reproduziert werden. Die paramagnetischen Relaxationszeiten, die sich dabei ergeben, liegen urn 10 -11 S und weisen einen sehr regelmiiJ3igen Gang mit der Ligandenvariation innerhalb der bileptischen Reihen auf.

show abstract

Section: Resultssupporting

confidence: 89%

Magnetokinetic Probing of Extremely Fast Electron Spin Relaxation in Paramagnetic Ruthenium Complexes*

Bürßner¹,

Wolff²,

Steiner³

1993

Zeitschrift Für Physikalische Chemie

View full text Add to dashboard Cite

show abstract

“…31,56,57 Dichloromethane was dried on a Grubbs-type solvent purification system. 58 Anhydrous 1,2-dichloroethane was purchased from Aldrich in a Sure/Seal bottle to ensure purity.…”

Section: Methodsmentioning

confidence: 99%

Electron-Rich CpIr(biphenyl-2,2′-diyl) Complexes with π-Accepting Carbon Donor Ligands

et al. 2012

View full text Add to dashboard Cite

Cp*IrIII and CpIrIII complexes have attracted interest as catalysts for oxidative transformations, and highly oxidizing iridium species are postulated as key intermediates in both catalytic water and C–H bond oxidation. Strongly electron-donating ligand sets have been shown to stabilize IrIV complexes. We describe the synthesis and reactivity of complexes containing the CpIr(biphenyl-2,2′-diyl) moiety stabilized by a series of strong donor carbon-based ligands. The oxidation chemistry of these complexes has been characterized electrochemically, and a singly oxidized IrIV species has been observed by X-band EPR for the complex CpIr(biph)(p-CNCH2SO2C6H4CH3).

show abstract

“…[65] Thin-layer chromatography (TLC) and column chromatography were performed with silicagel 60 F 254 (Merck) and silica gel 60, respectively.…”

Section: Methodsmentioning

confidence: 99%

Inter‐ and Intramolecular Photoinduced Electron Transfer of Flavin Derivatives with Extremely Small Reorganization Energies

Murakami

Ohkubo

Fukuzumi

2010

Chemistry A European J

View full text Add to dashboard Cite

Photoinduced electron transfer (ET) of a series of aromatic electron donors (D) to the singlet or triplet excited state of a flavin analogue (10-methylisoalloxazine: MeFl) and intermolecular back electron transfer (BET) from MeFl(*-) to D(*+) in benzonitrile (PhCN) has been investigated in light of the Marcus theory of ET. The rate constants of intermolecular photoinduced ET (k(et)) from D to the singlet excited state ((1)MeFl*) and the triplet excited state ((3)MeFl*) were determined by fluorescence quenching and enhanced decay rates of triplet-triplet (T-T) absorption by the presence of D, respectively. The k(et) values increase with an increase in the ET driving force to reach the diffusion-limit value that remains constant with a further increase in the ET driving force. Nanosecond laser flash photolysis was performed to determine the rate constants of intermolecular BET (k(bet)) from MeFl(*-) to D(*+) in PhCN. In contrast to the case of k(et), the driving force dependence of k(bet) shows a pronounced decrease towards the highly exothermic region. The reorganization energy (lambda) of intermolecular BET is determined to be 0.68 eV by applying the Marcus equation in the inverted region, where the k(bet) value decreases with increasing the BET driving force. The slowest BET was observed for BET from MeFl(*-) to N,N-dimethylaniline radical cation (DMA(*+)) with the k(bet) value of 3.5 x 10(6) M(-1) s(-1), which is 1600 times smaller than the diffusion rate constant in PhCN (5.6 x 10(9) M(-1) s(-1)). Then, DMA was linked to the 10-position of isoalloxazine to synthesize a DMA-flavin linked dyad (10-[4'-(N,N-dimethylamino)phenyl]-isoalloxazine: DMA-Fl). Photoexcitation of DMA-Fl results in photoinduced ET from the DMA moiety to the singlet excited state of Fl moiety to form the charge-separated (CS) state (DMA(*+)-Fl(*-)) that has an extremely long lifetime (2.1 ms) in PhCN at 298 K.

show abstract

Magnetic resonance studies of some low-spin d5 tris diimine complexes

Cited by 165 publications

References 0 publications

Magnetokinetic Probing of Extremely Fast Electron Spin Relaxation in Paramagnetic Ruthenium Complexes*

Magnetokinetic Probing of Extremely Fast Electron Spin Relaxation in Paramagnetic Ruthenium Complexes*

Electron-Rich CpIr(biphenyl-2,2′-diyl) Complexes with π-Accepting Carbon Donor Ligands

Inter‐ and Intramolecular Photoinduced Electron Transfer of Flavin Derivatives with Extremely Small Reorganization Energies

Contact Info

Product

Resources

About