NMR study of heterogeneity in pyridine-N-oxide...HCl crystal
Languages of publication
An origin of narrow 1H NMR signals in pyridine-N-oxide (PyO)...HCl crystal has been investigated by means of MAS, SPEDAS, NOESY and COSY techniques. Spectra of crystalline samples are compared with those of solid phase obtained from liquid PyO...HCl solutions (in acetonitile/H2O) after the heterogeneous phase separation. It has been concluded that partially resolved peaks in 1H NMR spectra of solids are related with heterogeneity of spin system and presence of different H-bond clusters of water molecules. NOESY spectra show no cross-peaks even at very long mixing time (500 ms). This indicates there is no exchange process between spins causing different peaks, and thus the corresponding molecular aggregates are captured in “islands of mobility8 without any channels sufficient for exchange. Appearance of MAS side bands as “pseudo8 cross-peaks in 2D NMR spectra using MAS/COSY technique is reported. In the case of accidental coincidence of spinning frequency (ωMAS) with spectral distances between some diagonal signals, intensive non-diagonal peaks are observed at the corresponding cross-positions. A misleading conclusion concerning spin coupling is easy to avoid using various ωMAS.
1 - 3 - 2004
1 - 3 - 2004
- Faculty of Physics, Vilnius University, Saulëtekio 9, LT-2040, Vilnius, Lithuania, email@example.com
- Slovenian NMR Centre, National Institute of Chemistry, SI-1000, Ljubljana, Slovenia, firstname.lastname@example.org
- Slovenian NMR Centre, National Institute of Chemistry, SI-1000, Ljubljana, Slovenia, email@example.com
-  V. Balevicius, A. Marsalka, V. Sablinskas and L. Kimtys: “Liquid-like Motion of Molecules in the Solid Phases of Organic Crystals as Studied by Raman and NMR Spectroscopy.”, J. Mol. Struct., Vol. 219, (1990), pp. 123–130. http://dx.doi.org/10.1016/0022-2860(90)80043-J[Crossref]
-  G. Dossech, C. Fressigne and A.H. Fuchs: “Premelting in Orientattionally Disordered Molecular Crystals. A Re-appraisal.”, J. Phys. Chem. Solids, Vol. 53, (1992), pp. 203–209. http://dx.doi.org/10.1016/0022-3697(92)90029-D[Crossref]
-  L. Kimtys, V. Balevicius and D.W. Aksenes: “Molecular Diffusion and Premelting in Hydrogen Bonded Organic Solids.”, J. Mol. Struct., Vol. 381, (1996), pp. 193–197. http://dx.doi.org/10.1016/0022-2860(95)09156-4[Crossref]
-  D.W. Aksnes and L. Kimtys: “1H NMR Studies of Cyclohexane Confined in Mesoporous Solids: Melting Point Depression and Pore Size Distribution.”, Appl. Magn. Reson., Vol. 23, (2002), pp. 51–62. http://dx.doi.org/10.1007/BF03166183[Crossref]
-  D.W. Aksnes, L.G. Gjerdåker and L. Kimtys: “Characterization of mesoporous materials by1H NMR.” In: J. Fraissard and O. Lapin (Eds.): Magnetic Resonance in Colloid and Interface Science (NATO Sci. Ser. II, Vol. 76), Kluwer Acad. Publ., Dordrecht, (2002), pp. 485–490.
-  M.H. Levitt: Spin dynamics, John Wiley & Sons Ltd., Chichester, 2001.
-  S. Ding and Ch.A. McDowell: ‘High-Resolution Proton NMR Spectra in Solids by Single-Pulse Excitation’, J. Magn. Reson. Ser. A, Vol. 111, (1994), pp. 212–214. http://dx.doi.org/10.1006/jmra.1994.1250[Crossref]
-  S. Ding and Ch.A. McDowell: “High-Resolution NMR Spectra of Nuclear Spin Systems under Homogeneous Interactions in Solids Exhibiting Line Narrowing Induced by the Memory Effect”, J. Magn. Reson. Ser. A, Vol. 117, (1995), pp. 171–178. http://dx.doi.org/10.1006/jmra.1995.0760[Crossref]
-  A.M. Gil, E. Alberti, C. Parreira, B.J. Goodfellow and B. Ravkin: “A Fast MAS1H NMR Study of Amino Acids and Proteins”, J. Mol. Struct., Vol. 602-603 (2002), pp. 357–366. http://dx.doi.org/10.1016/S0022-2860(01)00682-2[Crossref]
-  S. Ding and Ch.A. McDowell: “Two-Dimensional Proton Correlation Spectroscopy in Solids”, J. Magn. Reson. Ser. A, Vol. 115 (1995), pp. 141–144. http://dx.doi.org/10.1006/jmra.1995.1160[Crossref]
-  L. Zheng, K.W. Fisbein, R.G. Griffin and J. Herzfeld: “Two-Dimensional Solid-State1H-NMR and Proton Exchange”, J. Am. Chem. Soc., Vol. 115, (1993), pp. 6254–6261. http://dx.doi.org/10.1021/ja00067a045[Crossref]
-  V. Balevicius, J. Tamuliene and D. Hadzi: (to be published).
-  K. Nishikawa, Y. Kasahara and T. Ichioka: “Inhomogeneity of Mixing in Acetonitrile Aqueous Solution Studied by Small-Angle X-ray Scattering”, J. Phys. Chem. B, Vol. 106, (2002), pp. 693–700. http://dx.doi.org/10.1021/jp011964v[Crossref]
-  D. Pfeninning and D. Woermann: “Modification of the Transport Properties of a Membrane by Selective Solvation: Hyperfiltration of Acetonitrile/Water Mixtures”, J. Membrane Sci., Vol. 32, (1987), pp. 105–116. http://dx.doi.org/10.1016/S0376-7388(00)81578-1[Crossref]
-  T. Narayanan, A. Kumar, S. Venkatachalam, J. Jacob and B.V. Prafulla: “Exploration of a quadruple critical point in a quaternary liquid mixture.”, J. Chem. Phys., Vol. 102, (1995), pp. 9653–9658. http://dx.doi.org/10.1063/1.468784[Crossref]
-  G. Schneider: “Phasengleichgewichte in fluessungen Systemen bei hohen Drucken”, Ber. Bunsenges. Phys. Chem., Vol. 70, (1966), pp. 497–612.
-  M. Nakahara and Ch. Wakal: “Monomeric and Cluster States of Water Molecules in Organic Solvent”, Chem. Lett., (1992), pp. 809–812. [Crossref]
Publication order reference