GUEST HOST INTERACTIONS IN SODIUM ZEOLITE-Y - STRUCTURAL AND DYNAMIC NA-23 DOUBLE-ROTATION NMR-STUDY OF H2O, PME3, MO(CO)6, AND MO(CO)4(PME3)2 ADSORPTION IN NA56Y


JELINEK R., ÖZKAR S. , PASTORE H., MALEK A., OZIN G.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, cilt.115, sa.2, ss.563-568, 1993 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 115 Konu: 2
  • Basım Tarihi: 1993
  • Doi Numarası: 10.1021/ja00055a028
  • Dergi Adı: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
  • Sayfa Sayıları: ss.563-568

Özet

Na-23 double-rotation NMR (DOR) provides site-specific structural and dynamical information on guest-host interactions within sodium zeolite Y pores. Quantitative adsorption of H2O, PMe3, and Mo(CO)6 guests affects both the positions and line shapes of the N-23 resonances from specific extraframework Na+ sites. The evolution of the Na-23 DOR spectra with the progressive introduction of guest molecules allows one to probe direct ''solvation'' effects involving the Na+ cations in the larger supercages, as well as indirect effects on the Na+ cations in adjacent smaller sodalite cavities. Na-23 DOR experiments conducted at two magnetic field strengths confirm that PMe3 coadsorption in 8{Mo(CO)6}, 16{Pme3}-Na56Y, and PMe3 ligand-substitution in 8{cis-MO(CO)4(PMe3)2]-Na56Y give rise to progressive deshielding and enhanced quadrupolar interactions of the anchoring Na+ cations in the alpha-cages, relative to those of the starting material, 8{Mo(CO)6}-Na56Y. Spin-lattice relaxation measurements indicate that adsorption of PMe3 facilitates an increased motion of the Na+ cations and/or guest species inside the alpha-cages.