NMR study of kaolinite. 2. Proton, aluminum-27, and silicon-29 spin-lattice relaxations

Hayashi, Shigenobu; Ueda, Takahiro; Hayamizu, Kikuko; Akiba, Etsuo

doi:10.1021/j100205a059

Cited by 22 publications

(17 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This can be safely attributed to the presence of the paramagnetic Cu 2+ cations within the m-CPPD structure. Indeed, it is well established that paramagnetic ions usually lead to a very efficient pathway for nuclear relaxation. − Two relaxation mechanisms can be considered, namely, a through-space dipolar coupling between electrons and nuclei and a through-bond electronic interaction (Fermi contact). Both are usually present.…”

Section: Results and Discussionmentioning

confidence: 99%

Influence of Ionic Additives on Triclinic Calcium Pyrophosphate Dihydrate Precipitation

Ley-Ngardigal

Combes

Teychené

et al. 2016

Crystal Growth & Design

View full text Add to dashboard Cite

Triclinic calcium pyrophosphate dihydrate (t-CPPD) crystals are one of the two polymorphs of microcrystals that have been found in the joints of patients suffering from pseudogout. However, there is currently no treatment for inhibiting the formation of these crystals, which present a high inflammatory potential. In this context we studied in vitro the precipitation of t-CPPD in a stirred reactor under pH-and temperature-controlled conditions and determined the effect of selected biologically relevant ionic additives (Mg 2+ , Cu 2+ , Fe 3+ , Zn 2+ , S 2 O 3 2− ) on its formation. The results showed that 1 mM Fe 3+ , Zn 2+ , or Cu 2+ induced the most significant changes by partly inhibiting the crystallization of t-CPPD and favoring the formation of an amorphous-CPP phase (98 wt %) in the presence of Fe 3+ or a monoclinic-CPPD phase (78 or 71 wt %, respectively) in the presence of Zn 2+ or Cu 2+ . Correlations between 31 P solid-state NMR, XRD, and elemental analyses showed that the additive cations are inserted into the monoclinic-CPPD and/or amorphous-CPP phases. This study, which combines structural, morphological, and elemental analyses, paves the way toward a deeper comprehension of the role of ionic additives in preventing the formation of CPPD crystalline phases, and is a key step in long-term development of an effective therapeutic treatment.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Influence of Ionic Additives on Triclinic Calcium Pyrophosphate Dihydrate Precipitation

Ley-Ngardigal

Combes

Teychené

et al. 2016

Crystal Growth & Design

View full text Add to dashboard Cite

show abstract

“…All the curves are linear, which means direct relaxation through the dipole-dipole interaction with electron spins on paramagnetic impurities. 18 The T 1 values deduced are listed in Table 2 Our previous study 8 on kaolinite intercalation with DMSO revealed that the dipole-dipole interaction between methyl protons in DMSO and 29 Si in the host contributes to the relaxation due to the CH 3 rotation. The kaolinite applied was of Kanpaku origin, and its 29 Si T 1 was 1500 s under MAS of 3 kHz.…”

Section: Resultsmentioning

confidence: 99%

NMR Study of Kaolinite Intercalation Compounds with Formamide and Its Derivatives. 2. Dynamics of Guest Molecules

Xie

Hayashi

1999

J. Phys. Chem. B

Self Cite

View full text Add to dashboard Cite

Dynamics of guest molecules in kaolinite intercalation compounds with formamide (FA), formamide-N,N-d 2 (FA-d 2 ), N-methylformamide (NMF), and N,N-dimethylformamide (DMF) has been investigated through 2 H NMR spectra and 2 H and 13 C spin-lattice relaxations. 2 H NMR spectra of kaolinite/FA-d 2 in the temperature range 200-350 K are composed of a narrow central peak, a resolved Pake doublet (RD 1 ), and a distribution of Pake doublets (RDs). Quadrupole coupling constants and asymmetric factors obtained by fitting the spectral patterns indicate that RD 1 is ascribed to the host hydroxyl group formed through H-D exchange during the synthesis and RDs to the guest molecules in the interlayer. Temperature dependence of the quadrupole coupling constant reveals that the guest molecules undergo librational motions and that the librational amplitude increases with temperature. Spin-lattice relaxations of 1 H and 29 Si spins are due to paramagnetic impurities. 29 Si spins relax through direct dipole-dipole interaction with electron spins, and spin diffusion plays a role in the 1 H relaxation. Variable-temperature 13 C spin-lattice relaxation times T 1 of kaolinite intercalates with FA, FAd 2 , NMF, and DMF were recorded at two magnetic fields. T 1 decreases with increasing temperature in all the samples and increases at the higher magnetic field in the order of FA > FA-d 2 > NMF > DMF, where it is almost independent of the field in kaolinite/DMF. 13 C spins relax through dipole-dipole interactions with 1 H and 14 N by the librational motions of the molecules. The field dependence indicates that the correlation times are of the order of nano-seconds, and that they are in the order of FA > FA-d 2 > NMF > DMF. The temperature dependence of the relaxation time is caused by the amplitude change of the librational motions. 2 H spins relax mainly through paramagnetic impurities being assisted by spin diffusion at low temperatures, and fluctuation of quadrupole interaction caused by the librational motions contributes to the relaxation at higher temperatures.

show abstract

“…In previous works, we have measured 29Si and 2VA1 magic-anglespinning spectra and 1H wide-line and CRAMPS (Combined Rotation and Multiple Pulse Spectroscopy) spectra (Hayashi et al 1992a(Hayashi et al , 1992b. The presence of two crystallographically distinct sites was confirmed Copyright 9 1994, The Clay Minerals Society for Si and A1 atoms, tH spectra demonstrated that hydroxyl groups are in a rigid lattice state, i.e., spatially fixed.…”

Section: Introductionmentioning

confidence: 98%

²H NMR Study of Hydrogen Bonding in Deuterated Kaolinite

Hayashi

1994

Clays and clay miner.

Self Cite

View full text Add to dashboard Cite

Abstract--2H NMR spectra of synthetic deuterated kaolinite have been collected in the temperature range from 150 K to 350 K. Hydroxyl groups show a Pake doublet pattern with an asymmetry factor of 0. They are almost fixed spatially, and undergo a wobbling motion with increasing temperature. The quadrupole coupling constant is 273 +-3 kHz at 150 K, which indicates that interlayer hydrogen bonding is relatively weak.

show abstract

NMR study of kaolinite. 2. Proton, aluminum-27, and silicon-29 spin-lattice relaxations

Cited by 22 publications

References 6 publications

Influence of Ionic Additives on Triclinic Calcium Pyrophosphate Dihydrate Precipitation

Influence of Ionic Additives on Triclinic Calcium Pyrophosphate Dihydrate Precipitation

NMR Study of Kaolinite Intercalation Compounds with Formamide and Its Derivatives. 2. Dynamics of Guest Molecules

²H NMR Study of Hydrogen Bonding in Deuterated Kaolinite

Contact Info

Product

Resources

About

NMR study of kaolinite. 2. Proton, aluminum-27, and silicon-29 spin-lattice relaxations

Cited by 22 publications

References 6 publications

Influence of Ionic Additives on Triclinic Calcium Pyrophosphate Dihydrate Precipitation

Influence of Ionic Additives on Triclinic Calcium Pyrophosphate Dihydrate Precipitation

NMR Study of Kaolinite Intercalation Compounds with Formamide and Its Derivatives. 2. Dynamics of Guest Molecules

2H NMR Study of Hydrogen Bonding in Deuterated Kaolinite

Contact Info

Product

Resources

About

²H NMR Study of Hydrogen Bonding in Deuterated Kaolinite