Incoherent Quasielastic Neutron Scattering Study of the Relaxation Dynamics in Molybdenum-Oxide Based Keplerate Type Nanocages

Published

June 19, 2014

Author(s)

Antonio Faraone, Emiliano Fratini, Somenath Garai, Achim Muller, Madhu Sudan Tyagi, Timothy Jenkins, Eugene Mamontov, Rick L. Paul, John R. Copley, Piero Baglioni

Abstract

The single particle relaxation dynamics of hydrogen atoms in different oxomolybdate Keplerate type nanocages characterized by a (metal)₃₀ icosidodecahedron and a size of {approximately equal}25 A were studied using Incoherent Quasielastic Neutron Scattering. Measurements were performed on a compound with the {Mo₇₂Cr_{30} nanocage containing a sodium cation coordinated to 12 water molecules. Because of the presence of the methyl groups of the acetate ligands the related cavity mostly hydrophobic and represents an interesting model system for investigating the properties of water molecules under confined conditions in contact with hydrophobic surfaces. Both the dynamics of the cage themselves and determination of the effect of the cage polarity. The related {Mo}d72^Cr₃₀} compound was investigated previously [Faraone, et al,. JPCC 2009, 113, 14073] showing that the dynamics of the water molecules hydrating the nanocage is diffusive and heterogeneous, due to different local environments experienced by the water probes. The present results give a rather complete picture of the relaxation dynamics in diverse oxomolybdate Keplerate type nanocages.

Citation

Journal of Physical Chemistry C

Volume

118

Issue

24

Pub Type

Journals

Citation

Faraone, A. , Fratini, E. , Garai, S. , Muller, A. , , M. , Jenkins, T. , Mamontov, E. , Paul, R. , Copley, J. and Baglioni, P. (2014), Incoherent Quasielastic Neutron Scattering Study of the Relaxation Dynamics in Molybdenum-Oxide Based Keplerate Type Nanocages, Journal of Physical Chemistry C (Accessed April 20, 2024)