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

Date

1993-01-01

Author

JELINEK, R
Özkar, Saim
PASTORE, HO
MALEK, A
OZIN, GA

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

178
views

0
downloads

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.

Subject Keywords

Colloid and Surface Chemistry, Biochemistry, General Chemistry, Catalysis

URI

https://hdl.handle.net/11511/69991

Journal

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

DOI

https://doi.org/10.1021/ja00055a028

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

INTRAZEOLITE METAL-CARBONYL TOPOTAXY - A COMPREHENSIVE STRUCTURAL AND SPECTROSCOPIC STUDY OF INTRAZEOLITE GROUP-VI METAL HEXACARBONYLS AND SUBCARBONYLS Özkar, Saim; MOLLER, K; BEIN, T (American Chemical Society (ACS), 1990-12-01) This paper focuses attention on the intrazeolite anchoring, thermal decarbonylation, ligand exchange, and addition chemistry of M(CO)6-M'56Y, where M = Cr, Mo, W; M' = H, Li, Na, K, Rb, Cs. The key points to emerge from this study include the following. (i) M(CO)6-M'56Y samples have the hexacarbonylmetal(O) molecule associated with two alpha-cage extraframework cations (or Bronsted protons), via the oxygen end of two trans bonded carbonyls with a saturation loading of 2M(CO)6/alpha-cage. (ii) M(CO)6-M'56...
Synergistic Effects in Bimetallic Palladium-Copper Catalysts Improve Selectivity in Oxygenate Coupling Reactions Goulas, Konstantinos A.; SREEKUMAR, Sanil; Song, Yuying; Kharidehal, Purnima; Günbaş, Emrullah Görkem; Dietrich, Paul J.; Johnson, Gregory R.; Wang, Y. C.; Grippo, Adam M.; Grabow, Lars C.; Gokhale, Amit A.; Toste, F. Dean (American Chemical Society (ACS), 2016-06-01) Condensation reactions such as Guerbet and aldol are important since they allow for C-C bond formation and give higher molecular weight oxygenates. An initial study identified Pd-supported on hydrotalcite as an active catalyst for the, transformation, although this catalyst showed extensive undesirable decarbonylation. A catalyst containing Pd and Cu in a 3:1 ratio dramatically decreased decarbonylation, while preserving the high catalytic rates seen with Pd-based catalysts. A combination of XRD, EXAFS, TEM...
Cobalt Metallopeptide Electrocatalyst for the Selective Reduction of Nitrite to Ammonium Guo, Yixing; Stroka, Jesse R.; Kandemir, Banu; Dickerson, Claire E.; Bren, Kara L. (American Chemical Society (ACS), 2018-12-12) A cobalt-tripeptide complex (CoGGH) is developed as an electrocatalyst for the selective six-electron, eight-proton reduction of nitrite to ammonium in aqueous buffer near neutral pH. The onset potential for nitrite reduction occurs at -0.65 V vs Ag/AgCl (1 M KCl). Controlled potential electrolysis at -0.90 V generates ammonium with a faradaic efficiency of 90 +/- 3% and a turnover number of 3550 +/- 420 over 5.5 h. CoGGH also catalyzes the reduction of the proposed intermediates nitric oxide and hydroxylam...
Bonding self-assembled, compact organophosphonate monolayers to the native oxide surface of silicon Hanson, EL; Schwartz, J; Nickel, B; Koch, N; Danışman, Mehmet Fatih (American Chemical Society (ACS), 2003-12-24) A new method is described to prepare strongly bonded, compact monolayer films of alkyl- or arylphosphonates on the native oxide surface of Si (SiO2/Si). This method is illustrated for octadecyl- and alpha-quarterthiophene-2-phosphonates. For both cases, AFM shows comprehensive coverage of the SiO2/Si surface. The thickness of the continuous film of 4TP/SiO2/Si was measured both by AFM and by X-ray reflectivity to be ca. 18 Angstrom. Direct gravimetric analysis shows surface coverage by alpha-quarterthiophen...
Nanoparticle Nucleation Is Termolecular in Metal and Involves Hydrogen: Evidence for a Kinetically Effective Nucleus of Three {Ir3H2x center dot P2W15Nb3O62}(6-) in Ir(0)(n) Nanoparticle Formation From [(1,5-COD)Ir-I center dot P2W15Nb3O62](8-) Plus Dihydrogen Özkar, Saim (American Chemical Society (ACS), 2017-04-19) The nucleation process yielding Ir(0)(similar to 300) nanoparticles from (Bu4N)(5)Na-3[(1,5-COD)Ir center dot P2W15Nb3O62] (abbreviated hereafter as (COD)Ir center dot POM8-, where POM9- = the polyoxometalate, P2W15Nb3O629-) under H-2 is investigated to learn the true molecularity, and hence the associated kinetically effective nucleus (KEN), for nanoparticle formation for the first time. Recent work with this prototype transition metal nanoparticle formation system (J. Am. Chem. Soc. 2014, 136, 17601-17615...

Citation Formats

R. JELINEK, S. Özkar, H. PASTORE, A. MALEK, and G. OZIN, “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,” JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, pp. 563–568, 1993, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/69991.