Influence of Intermolecular Dipolar Interaction on Spin-Lattice Relaxation of the Three-Proton Group

ABSTRACTThe dipolar interaction of hydrogen (∼ 10 at. %) in boron-doped amorphous silicon has been studied using the Jeener-Broekaert pulse sequence. The sample was prepared on an Al foil substrate at a temperature of 230°C using a standard glow discharge system (operating at 1 W rf power). The diborane/silane ration was 10-4. The same sample was removed from the Al substrate using dilute hydrochloric acid. The Jeener-Broekaert pulse sequence consists of three pulses: π/2|x′ – τ1 – π/4|y′ – τ2 – π/4|y′ – echo. We measured T1D, the dipolar spin lattice relaxation time, for τ1 = 82 μs, τ1 = 100 μs and τ1 = 50 μs at 299°K. The value of τ1D was found to be independent of τ1. At 335°K we found τ1D to be much longer than at room temperature. The values of τ1D at 299 K, 314 K and 335 K are, respectively, 0.7 ms, 1.2 ms and 1.8 ms. From the data we estimate an activation energy for microscopic motion to be ∼ 0.2 eV.

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A nuclear magnetic resonance study of pyridoxal phosphate – metal ion interactions. II. Binding of manganese(II)

Canadian Journal of Chemistry ◽

10.1139/v79-173 ◽

1979 ◽

Vol 57 (9) ◽

pp. 1050-1055 ◽

Cited By ~ 9

Author(s):

Tenkasi S. Viswanathan ◽

Terrence J. Swift

Keyword(s):

Metal Ion ◽

Pyridoxal Phosphate ◽

Lattice Relaxation ◽

Dipolar Interaction ◽

Rotational Correlation Time ◽

Nuclear Magnetic Resonance Study ◽

Spin Lattice Relaxation ◽

Relaxation Rates ◽

Spin Lattice ◽

Nmr Methods

The line width and spin–lattice relaxation rates of phosphorus and proton nuclei in PLP have been measured as a function of temperature in the presence of Mn(II) using pulsed nmr methods. The T1M of 31P in PLP-Mn(II) is very close to the T1M values of β- and γ-phosphorus atoms in ATP–Mn(II) at ∼40 °C. The T1 data of 31P and 1H have been interpreted in terms of the dipolar interaction between the electron and nuclear spins. With the assumption that the Mn(II) interacts directly with the phosphate of PLP the rotational correlation time τc at 38 °C was calculated to be 7.6 × 10−10 s from phosphorus T1 data. This τc value was subsequently used to calculate metal–proton distances from proton T1 and T2 data. The results lead to the conclusion that the phosphate-bound metal interacts directly with the aldehyde oxygen in a 1:1 PLP–Mn(II) complex. The linewidth of the 13C resonances of PLP in the presence of Mn(II) supports this conclusion. The structure assigned for PLP–Mn(II) complex is in conformity with the structure for PLP-Co(II) complex.

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Spin–lattice relaxation dispersion in polymers: Dipolar-interaction components and short- and long-time limits

Solid State Nuclear Magnetic Resonance ◽

10.1016/j.ssnmr.2008.10.004 ◽

2009 ◽

Vol 35 (3) ◽

pp. 147-151 ◽

Cited By ~ 13

Author(s):

A. Gubaidullin ◽

T. Shakirov ◽

N. Fatkullin ◽

R. Kimmich

Keyword(s):

Lattice Relaxation ◽

Dipolar Interaction ◽

Relaxation Dispersion ◽

Spin Lattice Relaxation ◽

Time Limits ◽

Spin Lattice ◽

Long Time

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Electron Spin Relaxation of (Diphenyl) in Dimethoxyethane

Zeitschrift für Naturforschung A ◽

10.1515/zna-1975-6-726 ◽

1975 ◽

Vol 30 (6-7) ◽

pp. 883-890 ◽

Cited By ~ 1

Author(s):

F. Köksal ◽

G. J. Krüger

Keyword(s):

Spin Relaxation ◽

Relaxation Times ◽

Lattice Relaxation ◽

Dipolar Interaction ◽

Translational Diffusion ◽

Spin Lattice Relaxation ◽

High Concentration ◽

Electron Spin Relaxation ◽

Spin Lattice ◽

Electron Relaxation

Abstract The electron relaxation times T1 and T2 have been measured by ESR pulse techniques in solutions of normal and perdeuterated (diphenyl)- in dimethoxyethane at various radical concentrations and temperatures. The results are discussed in terms of different relaxation mechanisms. The most important contribution to spin-lattice relaxation at high concentration is dipolar interaction with other radical electrons modulated by translational diffusion. Spin-spin relaxation has in addition contributions from electron exchange and ion pairing.

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Nuclear spin-lattice relaxation in a multi-spin system. A spin 1/2 particle dipolar coupled to a spin 1 and spin 3/2 particle. 13C spin relaxation in urea

Australian Journal of Chemistry ◽

10.1071/ch9802571 ◽

1980 ◽

Vol 33 (12) ◽

pp. 2571

Author(s):

DM Doddrell ◽

KM Kleinschmidt

Keyword(s):

Spin Relaxation ◽

Matrix Theory ◽

Relaxation Times ◽

Coupled System ◽

Lattice Relaxation ◽

Dipolar Interaction ◽

Spin Lattice Relaxation ◽

Spin Lattice ◽

System A ◽

Density Matrix Theory

Density matrix theory is used to show that for S = 1/2, 1, 3/2 the decay of the I-magnetization (I = 4) in a two-spin IS dipolar coupled system is governed by the differential equation �� d<Iz>/dt= -k1{J(ωI-ωS)+3J(ωI)+6J(ωI+ωS)}{<Iz>-I0}�� -k2{6J(ωI+ωS)-J(ωI-ωS)}{<SZ>-S0} where k1 and k2 are positive constants dependent on S and the dipolar interaction constants. It follows that if <S2> = 0, as arises on S- irradiation, or <SZ> = S0, as in paramagnetic transition-metal complexes, the decay of the I-magnetization is exponential.�The theory is used to analyse 14N,2H dipolar-induced 13C spin relaxation in deuterated urea. It is shown that at low temperatures dipolar interactions dominate the relaxation whereas at high temperatures spin rotation effects become important. The relaxation times are very long; at 300 T1 is 114s.

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Investigation of the H1 Spin-Lattice Relaxation Times of Some Ammonium Compounds

Zeitschrift für Naturforschung A ◽

10.1515/zna-1979-0217 ◽

1979 ◽

Vol 34 (2) ◽

pp. 239-241

Author(s):

F. Köksal

Keyword(s):

Relaxation Times ◽

Lattice Relaxation ◽

Dipolar Interaction ◽

Interaction Constant ◽

Proton Spin ◽

Spin Lattice Relaxation ◽

Ammonium Ion ◽

Ammonium Ions ◽

Reorientational Motion ◽

Spin Lattice

Abstract The temperature dependence of the proton spin-lattice relaxation times of (NH4)2Al(SO4)2, (NH4)2 MoO4, NH4NH2SO3 and (NH4)2SnCl6 has been investigated in the temperature range 100- 500 K. The experimental results indicate that intra H-H dipolar interaction, modulated by reorientational motion of the ammonium ion, is the dominant relaxation mechanism between 100 and 200 K. The activation energies for the reorientational motion of the ammonium ions were found to be 1.54, 1.56, 0.99, and 0.91 kcal/mole, respectively. Furthermore, it has been detected that above 200 K the spin-rotational interactions of the ammonium ions contribute to the spin-lattice relaxation. The average value of the mean-square spin-rotational interaction constant for NH4+ was found to be C2 = 1.42 × 1010 s-2

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Protonenspin-Relaxation durch Spinrotationswechselwirkung in kristallinen Methylnaphthalinen/Proton Spin-Lattice Relaxation on Crystalline Methylnaphthalenes by Spin-Rotational Interaction

Zeitschrift für Naturforschung A ◽

10.1515/zna-1975-1015 ◽

1975 ◽

Vol 30 (10) ◽

pp. 1302-1307 ◽

Cited By ~ 6

Author(s):

J. U. von Schütz

Keyword(s):

Spin Relaxation ◽

Lattice Relaxation ◽

Dipolar Interaction ◽

Proton Spin ◽

Spin Lattice Relaxation ◽

Field Range ◽

Spin Lattice ◽

Methyl Naphthalene ◽

First Time ◽

Rotational Interaction

Abstract The high temperature behavior of the longitudinal proton spin relaxation time T1 of several methyl naphthalene crystals, differing in the arrangement and number of the substituted CH3-groups, was investigated in a large magnetic field range. It could be prooved - for the first time via proton spin relaxation - that in solids the fast reorientation of CH3-groups with low hindering barriers can lead to remarkable contributions to the total relaxation rate by spin-rotational interaction, in addition to the well known dipolar interaction discussed in preceeding works.

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