Investigation of molecular motion of Cl-adamantane in the nanoprous zeolite by 13C NMR dipolar dephasing and variable contact time measurements

Document Type : Reasearch Paper

Author

• A. R. Samadi-Maybodi

Analytical Division Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.

10.7508/ijnd.2016.01.008

Abstract

Dipolar-dephasing method provides some information about the strength of dipolar coupling in solids. Dipolar dephasing technique measures the time for a polarized carbon nucleus to lose its magnetization once the proton locking field is terminated. The dynamics of guest molecules adsorbed within the cavities and channels of nonporouszeolite strongly depend on the structure and chemical composition of the nonporouszeolite. In this work solid-state ¹³C NMR spectroscopy and dipolar dephasing technique were applied to determine the extent of motion 1-Chloroadamantaneloaded in nonporouszeolite-Y. Loading of 1-Chloroadamantane into the supercages of the zeolite-Y (with R=100 and R=2.35, R=Si/Al) was carried out by a vapor phase impregnationand solution impregnation methods. The accuracy of dipolar dephasing method was first investigated with the aid of pure 1-Chloroadamantaneto determine the degree of motion in the nonporousof zeolite-Y. Results indicated that the C_d signal of the 1-Chloroadamantanein the nonporous zeolite-Y decays faster than that the C_b and C_g, demonstrating that dipolar interaction for this carbon (C_d) is stronger. However, the rate of signal decay C_d for the 1-Chloroadamantaneloaded in zeolite -Y (R=2.35) is less than that loaded in zeolite-Y (R=100). 

Keywords

• 1-Chloroadamantane
• CPMAS NMR
• Dipolar dephasing
• Impregnation
• Molecular motion
• Nonporous
• Zeolite-Y

20.1001.1.20088868.2016.7.1.8.8

Main Subjects

• Nanochemistry
• Nanomaterial
• Nanotechnology

---

References

[1] Hohwy M., Rienstra C. M., Jaroniec C. P., Griffin R. G., (1999), Fivefold symmetric homonuclear dipolar recoupling in rotating solids. Application to double quantum spectroscopy. J. Chem. Phy. 110: 7983-7992.

[2]  Bovey F. A., Jelinski L. W., (1985), The observation of chain motion in macromolecules by 13C and 1H nuclear magnetic resonance spectroscopy. J. Phys. Chem. 89: 571-583.

[3]  Yu Y., Brown G. R., (1993), Molecular Mmobilities of Poly(N-alkylacrylamide) resins as studied by solid-state 13C- 1H dipolar dephasing NMR. Macromolec. 26: 4872-4877.

[4]  Mueller K.T., Jarvie T. P., Aurentz D. J., Roberts B. W., (1995), The REDOR transform: direct calculation of internuclear couplings from dipolar-dephasing NMR data. Chem. Phys. Lett. 242: 535-542.

[5]  Alemany L. B., Grant D. M., Alger T. D., Pugmire R. J. J., (1983), Cross polarization and magic angle sample spinning NMR spectra of model organic compounds. Effect of the 13C-lH dipolar interaction on cross polarization and carbonproton Dephasing. Am. Chem. Soc. 105: 6697-6704.

[6]  Huang Y., G. D. F. R., Butler I. S., Fred M., (1991), Study of Molecular Motlons in the Orientationally Disordered organic solids 1-Bromoadamantane and 1-Adamantanecarboxylic acid by 13C NMR spin-lattice relaxation and dipolar dephasing time measurements. J. Phys. Chem. 95: 2151-2156.

[7]  Munowitz M. G., Griffin R. G., Bodenhausen G., Huang T. H., (1981), Two-dimensional rotational spin-echo nuclear magnetic resonance in solids: correlation of chemical shift and dipolar interactions. J. Am. Chem. Soc. 103: 2529-2533.

[8]  Fyfe C. A., Wong-Moon K. C., Huang Y., Grondey H., (1995), Structural investigations of SAPO-37 molecular sieve by coherence-transfer and dipolar-dephasing solidstate nuclear magnetic resonance experiments. Microporous Mater. 5: 29-37.

[9]  Nishimura K., Naito A., Tuzi S., Saito H., (1999), Analysis of dipolar Dephasing pattern in I-Sn multispin system for obtaining the information of molecular packing and its application to crystalline N-Acetyl-Pro-Gly-Phe by REDOR solid state NMR. J. Phys. Chem. B. 103: 8398-8404.

[10] Mao J. D., Schmidt-Rohr K., (2003) Recoupled longrange C.H dipolar dephasing in solid-state NMR, and its use for spectral selection of fused aromatic rings. J. Magn. Reson. 162: 217-227.

[11] Yu Y., Brown G. R., (1993), Molecular mobilities of Poly(N-alkylacrylamide) resins as studied by solid-state 13C- 1H dipolar dephasing NMR. Macromolec. 26: 4872-4877.

[12] Liiti T., Maunu S. L., Sipil J., Hortling B., (2002), Application of solid-state 13C NMR spectroscopy and dipolar dephasing technique to determine the extent of

condensation in technical lignins. Solid State Nucl. Mag. 21: 171-186.

[13] Mueller K. T., (1995), Analytic solutions for the time evolution of dipolar-Dephasing NMR signals. J. Phys. Chem. 113: 81-93.