@article {491,
	title = {Multiple-Quantum Nmr-Study of the Distribution of Benzene in Nay Zeolite},
	journal = {Journal of Physical Chemistry},
	volume = {96},
	year = {1992},
	note = {J Phys Chem-UsJu555Times Cited:26Cited References Count:24},
	month = {Oct 15},
	pages = {8517-8522},
	abstract = {<p>We have used multiple-quantum NMR to measure the apparent spin network size as a function of excitation time of NaY zeolite samples containing varying amounts of benzene. Behavior observed at low concentrations of benzene was consistent with the presence of isolated clusters of benzene molecules in the supercages, with a statistical distribution of benzene molecules between supercages. Behavior observed at high concentrations of benzene was consistent with the presence of weakly coupled clusters of benzene molecules, with a uniform distribution of benzene molecules between supercages.</p>
},
	keywords = {solids},
	isbn = {0022-3654},
	doi = {Doi 10.1021/J100200a057},
	url = {<Go to ISI>://WOS:A1992JU55500057},
	author = {Pearson, J. G. and Chmelka, B. F. and Shykind, D. N. and Pines, A.}
}
@article {511,
	title = {Nmr-Study of the Distribution of Aromatic-Molecules in Nay Zeolite},
	journal = {Journal of Physical Chemistry},
	volume = {95},
	year = {1991},
	note = {J Phys Chem-UsEr473Times Cited:70Cited References Count:64},
	month = {Jan 10},
	pages = {303-310},
	abstract = {<p>Local and macroscopic distributions of adsorbed benzene, 1,3,5-trimethylbenzene, and hexamethylbenzene (HMB) molecules among the intracrystalline of NaY zeolite samples have been investigated by Xe-129 and multiple-quantum NMR. Xenon-129 NMR, a sensitive probe of macroscopic distributions of molecules in zeolites at room temperature, demonstrates the importance of sample heat treatment in distributing an adsorbate homogeneously throughout a collection of zeolite particles. NaY samples containing organic guests adsorbed a temperatures near the bulk species\&$\#$39; melting point produce multiple or broad xenon lines characteristic of macroscopic (i.e., interparticle) adsorbate concentration gradients. After thorough heat treatment of the samples at elevated temperatures, the xenon spectrum collapses to a single sharp line, consistent with a macroscopically uniform distribution. For HMB adsorbed in NaY, \&quot;counting\&quot; hydrogen clusters by multiple-quantum NMR reveals intraparticle HMB distributions consistent with one molecular per cavity at low loadings (average bulk loading less-than-or-equal-to 1 molecule per cavity) and two molecules per cavity at higher loadings.</p>
},
	keywords = {catalysts},
	isbn = {0022-3654},
	doi = {Doi 10.1021/J100154a056},
	url = {<Go to ISI>://WOS:A1991ER47300056},
	author = {Chmelka, B. F. and Pearson, J. G. and Liu, S. B. and Ryoo, R. and Demenorval, L. C. and Pines, A.}
}
