A study by solid-state cesium-133 and proton NMR of a hydrated and dehydrated cesium mordenite

Chu, Po-Jen; Gerstein, B. C.; Nunan, John; Klier, K.

doi:10.1021/j100297a025

Cited by 48 publications

(34 citation statements)

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“…[22][23][24] We present here only the conventions used in the current work. The two most important interactions to consider presently are the nuclear magnetic shielding interaction and the quadrupolar interaction.…”

Section: Background Theorymentioning

confidence: 99%

Chlorine-35/37 NMR Spectroscopy of Solid Amino Acid Hydrochlorides: Refinement of Hydrogen-Bonded Proton Positions Using Experiment and Theory

2006

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Trends in the chlorine chemical shift (CS) tensors of amino acid hydrochlorides are investigated in the context of new data obtained at 21.1 T and extensive quantum chemical calculations. The analysis of chlorine-35/37 NMR spectra of solid L-tryptophan hydrochloride obtained at two magnetic field strengths yields the chlorine electric field gradient (EFG) and CS tensors, and their relative orientations. The chlorine CS tensor is also determined for the first time for DL-arginine hydrochloride monohydrate. The drastic influence of 1 H decoupling at 21.1 T on the spectral features of salts with particularly small 35 Cl quadrupolar coupling constants (C Q ) is demonstrated. The chlorine CS tensor spans (Ω) of hydrochloride salts of hydrophobic amino acids are found to be larger than those for salts of hydrophilic amino acids. A new combined experimental-theoretical procedure is described in which quantum chemical geometry optimizations of hydrogen-bonded proton positions around the chloride ions in a series of amino acid hydrochlorides are cross-validated against the experimental chlorine EFG and CS tensor data. The conclusion is reached that the relatively computationally inexpensive B3LYP/ 3-21G* method provides proton positions which are suitable for subsequent higher-level calculations of the chlorine EFG tensors. The computed value of Ω is less sensitive to the proton positions. Following this cross-validation procedure, |C Q ( 35 Cl)| is generally predicted within 15% of the experimental value for a range of HCl salts. The results suggest the applicability of chlorine NMR interaction tensors in the refinement of proton positions in structurally similar compounds, e.g., chloride ion channels, for which neutron diffraction data are unavailable. IntroductionThe availability of high-field solid-state nuclear magnetic resonance (NMR) spectrometers, e.g., those with 1 H resonance frequencies of 800 MHz, 900 MHz, and above, has created new opportunities for the study of quadrupolar nuclei (I > 1/ 2) with low resonance frequencies or large quadrupole moments, and for nuclei with both of these properties. For example, Stebbins et al. have described applications of 18.8 and 21.1 T solid-state 27 Al, 17 O, 39 K, and 35 Cl NMR spectroscopy to study oxide materials. 1-3 Gan et al. used magnetic fields as high as 40 T to achieve chemical shift resolution between four different aluminum environments in aluminoborate. 4 Ellis and colleagues have applied high-field 67 Zn NMR at low temperature to study zinc binding environments of biological relevance. 5,6,7,8 Magicangle-spinning (MAS) NMR in a magnetic field of 19.6 T has been applied by Wu and co-workers to detect potassium cations in guanine-quadruplex structures 9 as well as to explore cation-π interactions in alkali metal tetraphenylborates. 10 Cross and coworkers have demonstrated the utility of 17 O solid-state NMR at 21.1 T for characterizing the ion channel gramicidin. 11,12 The major reason that higher fields are so beneficial for the study of quadrupolar nuclei in ...

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Section: Background Theorymentioning

confidence: 99%

Chlorine-35/37 NMR Spectroscopy of Solid Amino Acid Hydrochlorides: Refinement of Hydrogen-Bonded Proton Positions Using Experiment and Theory

2006

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“…The isotope 133Cs has a natural abundance of 100%, a nuclear spin of I = 7/2, and a weak quadrupole moment. Starting with the work of Chu et al [373], static 133Cs NMR and 133Cs MAS NMR spectroscopy was applied to monitor the local structures of cesium cations in hydrated and dehydrated mordenite. The crystallographic sites of cations in mordenite are labeled SII, SIV, and SVI and have relative cesium occupancies of 3.78: 1.86: 1.75 [374] .…”

Section: Cs Mas Nmr Spedroscopy Of Cesium Cations In Hydrated and mentioning

confidence: 99%

Characterization of Zeolites — Infrared and Nuclear Magnetic Resonance Spectroscopy and X-Ray Diffraction

Karge¹,

Hunger²,

Beyer³

1999

Catalysis and Zeolites

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“…Under favorable conditions, experiments performed on magic-angle spinning (MAS) and stationary powdered samples can yield information on the electric field gradient (EFG) tensor, the chemical shift (CS) tensor, and the relative orientations of these tensors. 41,42 In principle these two tensorial quantities offer different, complementary information on the bonding environment. Until recently, there has been little NMR spectroscopic characterization of cations involved in cation-π interactions, 43,44 particularly in the solid state.…”

Section: Introductionmentioning

confidence: 99%

Solid-State ²³Na NMR Study of Sodium Lariat Ether Receptors Exhibiting Cation−π Interactions

et al. 2006

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Noncovalent cation-pi interactions are important in a variety of supramolecular and biochemical systems. We present a 23Na solid-state nuclear magnetic resonance (SSNMR) study of two sodium lariat ether complexes, 1 and 2, in which a sodium cation interacts with an indolyl group that models the side chain of tryptophan. Sodium-23 SSNMR spectra of magic-angle spinning (MAS) and stationary powdered samples have been acquired at three magnetic field strengths (9.4, 11.75, 21.1 T) and analyzed to provide key information on the sodium electric field gradient and chemical shift (CS) tensors which are representative of the cation-pi binding environment. Triple-quantum MAS NMR spectra acquired at 21.1 T clearly reveal two crystallographically distinct sites in both 1 and 2. The quadrupolar coupling constants, CQ(23Na), range from 2.92 +/- 0.05 MHz for site A of 1 to 3.33 +/- 0.05 MHz for site B of 2; these values are somewhat larger than those reported previously by Wong et al. (Wong, A.; Whitehead, R. D.; Gan, Z.; Wu, G. J. Phys. Chem. A 2004, 108, 10551) for NaBPh4, but very similar to the values obtained for sodium metallocenes by Willans and Schurko (Willans, M. J.; Schurko, R. W. J. Phys. Chem. B 2003, 107, 5144). We conclude from the 21.1 T data that the spans of the sodium CS tensors are less than 20 ppm for 1 and 2 and that the largest components of the EFG and CS tensors are non-coincident. Quantum chemical calculations of the NMR parameters substantiate the experimental findings and provide additional insight into the dependence of CQ(23Na) on the proximity of the indole ring to Na+. Taken together, this work has provided novel information on the NMR interaction tensors characteristic of a sodium cation interacting with a biologically important arene.

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A study by solid-state cesium-133 and proton NMR of a hydrated and dehydrated cesium mordenite

Cited by 48 publications

References 0 publications

Chlorine-35/37 NMR Spectroscopy of Solid Amino Acid Hydrochlorides: Refinement of Hydrogen-Bonded Proton Positions Using Experiment and Theory

Chlorine-35/37 NMR Spectroscopy of Solid Amino Acid Hydrochlorides: Refinement of Hydrogen-Bonded Proton Positions Using Experiment and Theory

Characterization of Zeolites — Infrared and Nuclear Magnetic Resonance Spectroscopy and X-Ray Diffraction

Solid-State ²³Na NMR Study of Sodium Lariat Ether Receptors Exhibiting Cation−π Interactions

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A study by solid-state cesium-133 and proton NMR of a hydrated and dehydrated cesium mordenite

Cited by 48 publications

References 0 publications

Chlorine-35/37 NMR Spectroscopy of Solid Amino Acid Hydrochlorides: Refinement of Hydrogen-Bonded Proton Positions Using Experiment and Theory

Chlorine-35/37 NMR Spectroscopy of Solid Amino Acid Hydrochlorides: Refinement of Hydrogen-Bonded Proton Positions Using Experiment and Theory

Characterization of Zeolites — Infrared and Nuclear Magnetic Resonance Spectroscopy and X-Ray Diffraction

Solid-State 23Na NMR Study of Sodium Lariat Ether Receptors Exhibiting Cation−π Interactions

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Solid-State ²³Na NMR Study of Sodium Lariat Ether Receptors Exhibiting Cation−π Interactions