Pulsed Transient Nutation Experiments of the Photo-Excited Triplet State

Kouskov, Vladimir; Sloop, David J.; Liu, Shang-Bin; Lin, Tien‐Sung

doi:10.1006/jmra.1995.9977

Cited by 15 publications

(12 citation statements)

References 5 publications

(12 reference statements)

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“…Here the Rabi frequency of the electron spin system (rotating frame in the preparation pulse) was made to approximately match the Lamor frequency of the nuclear system (laboratory frame) to fulfill the Hartmann-Hahn condition for an effective polarization transfer. Previously, we have also observed similar effects in the pulsed transient nutation experiments where the spectral diffusion and polarization transfer processes in the LF transition are one order of magnitude greater than those of the HF transition (10). The effective polarization transfer in the LF transition is attributed to the substantial contribution from the nonsecular hyperfine terms.…”

Section: Figsupporting

confidence: 53%

“…A special ENDOR cavity with multiple-turn NMR coils wound around the sample was used in the measurement, which is similar to the setup used in the previous pulsed transient nutation experiments (10).…”

Section: Methodsmentioning

confidence: 99%

“…In the LF transition, the hyperfine terms of some protons are dominated by nonsecular terms, i.e., B i Ͼ A i , which yield deep ESEEM (11). One may reexpress the nonsecular hyperfine terms up to the second order and keep the flip-flop terms in the effective Hamiltonian (10,12):…”

Section: Figmentioning

confidence: 98%

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Dynamic Nuclear Polarization in Pulsed ENDOR Experiments

Kouskov

Sloop

Liu

et al. 1999

Journal of Magnetic Resonance

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Section: Figsupporting

confidence: 53%

Section: Methodsmentioning

confidence: 99%

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Dynamic Nuclear Polarization in Pulsed ENDOR Experiments

Kouskov

Sloop

Liu

et al. 1999

Journal of Magnetic Resonance

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“…The maximal achievable B 1 amplitude was measured using an ESE-detected transient nutation experiment in which the transient nutation during a preparation pulse is monitored using a two-pulse ESE sequence (28). As follows from Fig.…”

Section: Performancementioning

confidence: 99%

“…Therefore, many modern homebuilt spectrometers operating at lower microwave frequencies (from S to K u band) were constructed as broadband instruments (15)(16)(17)(18)(19)(20)(21). Because our K a -band spectrometer was conceived with ESEEM applications in mind, it was logical for us to build it as a broadband instrument operating in the entire K a band (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Until recently, achieving such a goal would be next to impossible because many of the necessary broadband K a -band microwave components were not available commercially.…”

Section: Introductionmentioning

confidence: 99%

26.5–40 GHz Ka-band pulsed EPR spectrometer

Astashkin

Enemark

Raitsimring

2006

Concepts Magn. Reson.

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ABSTRACT:The design and performance of a new homebuilt K a -band pulsed electron paramagnetic resonance (EPR) spectrometer is described. The spectrometer is unique in that it is broadband and allows experiments to be performed at any operational frequency within the range from 26.5 to 40 GHz. The high-power microwave amplifier employed in this spectrometer allowed us to use resonators with low quality factor and to achieve a minimum inversion microwave pulse duration of 11 ns. As a result, this spectrometer can be used for all types of pulsed EPR experiments, including electron spin echo envelope modulation (ESEEM), electron-nuclear double resonance (ENDOR), and electron-electron double resonance (ELDOR) with a difference between the pumping and observation frequencies of up to several hundred megahertz. The timing is controlled by an arbitrary waveform generator with 12 digital outputs and 1 ns time resolution. The spectrometer control/data acquisition software is home-written and allows an easy implementation of any one-or two-dimensional experiment using sweep definition tables.

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Novel Pulsed Electron Paramagnetic Resonance Techniques for the Studies of Structure and Dynamics of Photo‐excited Triplet State of Organic Molecules: A Professional Journey

Lin

2017

J Chinese Chemical Soc

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We present a few novel pulsed electron paramagnetic resonance techniques developed in our laboratory for the studies of structure and dynamics of the photo-excited triplet state of organic molecules. We discuss many aspects of these new techniques and the significances of these measurements: (1) enhancing NMR signal intensity by dynamic nuclear polarization -integrated solid effect, (2) performing magnetic resonance in zero-field and low-field by pulsed microwave, (3) mapping molecular motion of organic crystals by pulsed zero-field and low-field experiments, (4) probing spin dynamics at level anti-crossing by fast field switching, (5) measuring hyperfine interaction by electron spin echo envelop modulation and spinecho electron nuclear double resonance and (6) detecting spin dynamics, nuclear quantum oscillation, entanglements and new avenues for quantum computer. We have employed the highly electron spin polarized pentacene triplet state as the model system in all of our pulsed EPR experiments. We performed most of our experiments at room temperature. The goals of our studies are aiming to improve spin detectability, to probe molecular dynamics, to determine electronic structures, to measure molecular interaction and motion, and to examine quantum coherence and oscillation which may yield new avenues in the applications of pulsed EPR techniques to quantum computer. a span of 35 years, he and his collaborators developed many novel pulsed electron paramagnetic resonance (EPR) techniques to study the dynamics of photo-excitation of organic molecules, to probe the spin interaction at the level anti-crossing region, to enhance the nuclear polarization by dynamic nuclear polarization, and to detect quantum oscillation and entanglement. His research interests include the applications of EPR techniques to study the structure and dynamics of the photo-excited triplet state of organic molecules, the reactivity of free radicals in photochemical reactions, and to identify free radical species (nitric oxide and oxygen-containing free radicals) associated with physical disorders in biomedical research. In collaboration with Prof. C.Y. Mou of the National Taiwan University, they applied EPR techniques to study the biocatalysis of transition-metalcontaining enzymes encapsulated in mesoporous silica materials.

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Pulsed Transient Nutation Experiments of the Photo-Excited Triplet State

Cited by 15 publications

References 5 publications

Dynamic Nuclear Polarization in Pulsed ENDOR Experiments

Dynamic Nuclear Polarization in Pulsed ENDOR Experiments

26.5–40 GHz Ka-band pulsed EPR spectrometer

Novel Pulsed Electron Paramagnetic Resonance Techniques for the Studies of Structure and Dynamics of Photo‐excited Triplet State of Organic Molecules: A Professional Journey

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