000188359 001__ 188359 000188359 005__ 20210129215159.0 000188359 0247_ $$2doi$$a10.1021/jp412228r 000188359 0247_ $$2ISSN$$a1932-7447 000188359 0247_ $$2ISSN$$a1932-7455 000188359 0247_ $$2WOS$$aWOS:000333005700059 000188359 0247_ $$2altmetric$$aaltmetric:2150533 000188359 037__ $$aFZJ-2015-01765 000188359 082__ $$a540 000188359 1001_ $$0P:(DE-Juel1)143752$$aJalarvo, Niina$$b0$$eCorresponding Author$$ufzj 000188359 245__ $$aStructure and Dynamics of Octamethyl-POSS Nanoparticles 000188359 260__ $$aWashington, DC$$bSoc.$$c2014 000188359 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article$$bjournal$$mjournal$$s1426174321_8449 000188359 3367_ $$2DataCite$$aOutput Types/Journal article 000188359 3367_ $$00$$2EndNote$$aJournal Article 000188359 3367_ $$2BibTeX$$aARTICLE 000188359 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000188359 3367_ $$2DRIVER$$aarticle 000188359 520__ $$aPolyoligosilsesquioxanes (POSS) are a large family of Si–O cage molecules that have diameters of 1–2 nm and can be viewed as perfectly monodisperse silica nanoparticles. POSS can be synthesized with a wide variety of functional ligands attached to their surfaces. Here we report the results of a comprehensive study of the crystal structure and ligand dynamics of one of the simplest POSS nanoparticles, octamethyl-POSS or Si8O12(CH3)8, where the central Si8O12 cage is surrounded by eight methyl ligands. Neutron powder diffraction data highlight the presence of strongly temperature-dependent methyl group rotational dynamics. Vibrational spectra were measured using Raman and inelastic neutron scattering techniques, and the results of the measurements were compared with the predictions of density functional theory calculations. In particular, the inelastic neutron scattering spectra show the fundamental and first overtone transitions of the methyl torsional vibrations; these transitions are forbidden in both Raman and infrared spectroscopy for the molecule with its ideal octahedral symmetry. The energies of these transitions are used to determine the height of the torsional energy barrier. Direct measurements of the methyl group dynamics using quasielastic incoherent neutron scattering provide the hydrogen atom jump distance and the activation energy for rotation of the methyl groups. Together these results provide a detailed picture of the structure and ligand dynamics of this POSS molecule. 000188359 536__ $$0G:(DE-HGF)POF2-54G24$$a54G - JCNS (POF2-54G24)$$cPOF2-54G24$$fPOF II$$x0 000188359 536__ $$0G:(DE-HGF)POF2-451$$a451 - Soft Matter Composites (POF2-451)$$cPOF2-451$$fPOF II$$x1 000188359 588__ $$aDataset connected to CrossRef, juser.fz-juelich.de 000188359 7001_ $$0P:(DE-HGF)0$$aGourdon, Olivier$$b1 000188359 7001_ $$0P:(DE-HGF)0$$aEhlers, Georg$$b2 000188359 7001_ $$0P:(DE-HGF)0$$aTyagi, Madhusudan$$b3 000188359 7001_ $$0P:(DE-HGF)0$$aKumar, Sanat K.$$b4 000188359 7001_ $$0P:(DE-HGF)0$$aDobbs, Kerwin D.$$b5 000188359 7001_ $$0P:(DE-HGF)0$$aSmalley, Robert J.$$b6 000188359 7001_ $$0P:(DE-HGF)0$$aGuise, William E.$$b7 000188359 7001_ $$0P:(DE-HGF)0$$aRamirez-Cuesta, Anibal$$b8 000188359 7001_ $$0P:(DE-HGF)0$$aWildgruber, Christoph$$b9 000188359 7001_ $$0P:(DE-HGF)0$$aCrawford, Michael K.$$b10 000188359 773__ $$0PERI:(DE-600)2256522-X$$a10.1021/jp412228r$$gVol. 118, no. 10, p. 5579 - 5592$$n10$$p5579 - 5592$$tThe @journal of physical chemistry <Washington, DC> / C$$v118$$x1932-7455$$y2014 000188359 8564_ $$uhttp://pubs.acs.org/doi/abs/10.1021/jp412228r 000188359 909CO $$ooai:juser.fz-juelich.de:188359$$pVDB 000188359 915__ $$0StatID:(DE-HGF)0100$$2StatID$$aJCR 000188359 915__ $$0StatID:(DE-HGF)0110$$2StatID$$aWoS$$bScience Citation Index 000188359 915__ $$0StatID:(DE-HGF)0111$$2StatID$$aWoS$$bScience Citation Index Expanded 000188359 915__ $$0StatID:(DE-HGF)0150$$2StatID$$aDBCoverage$$bWeb of Science Core Collection 000188359 915__ $$0StatID:(DE-HGF)0199$$2StatID$$aDBCoverage$$bThomson Reuters Master Journal List 000188359 915__ $$0StatID:(DE-HGF)0200$$2StatID$$aDBCoverage$$bSCOPUS 000188359 915__ $$0StatID:(DE-HGF)0300$$2StatID$$aDBCoverage$$bMedline 000188359 915__ $$0StatID:(DE-HGF)1150$$2StatID$$aDBCoverage$$bCurrent Contents - Physical, Chemical and Earth Sciences 000188359 915__ $$0StatID:(DE-HGF)9900$$2StatID$$aIF < 5 000188359 9141_ $$y2014 000188359 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)143752$$aForschungszentrum Jülich GmbH$$b0$$kFZJ 000188359 9132_ $$0G:(DE-HGF)POF3-623$$1G:(DE-HGF)POF3-620$$2G:(DE-HGF)POF3-600$$9G:(DE-HGF)POF3-6G4$$aDE-HGF$$bForschungsbereich Materie$$lVon Materie zu Materialien und Leben$$vFacility topic: Neutrons for Research on Condensed Matter$$x0 000188359 9132_ $$0G:(DE-HGF)POF3-551$$1G:(DE-HGF)POF3-550$$2G:(DE-HGF)POF3-500$$aDE-HGF$$bKey Technologies$$lBioSoft – Fundamentals for future Technologies in the fields of Soft Matter and Life Sciences$$vFunctional Macromolecules and Complexes$$x1 000188359 9132_ $$0G:(DE-HGF)POF3-621$$1G:(DE-HGF)POF3-620$$2G:(DE-HGF)POF3-600$$9G:(DE-HGF)POF3-6215$$aDE-HGF$$bForschungsbereich Materie$$lVon Materie zu Materialien und Leben$$vIn-house research on the structure, dynamics and function of matter$$x2 000188359 9131_ $$0G:(DE-HGF)POF2-54G24$$1G:(DE-HGF)POF2-540$$2G:(DE-HGF)POF2-500$$3G:(DE-HGF)POF2$$4G:(DE-HGF)POF$$aDE-HGF$$bStruktur der Materie$$lForschung mit Photonen, Neutronen, Ionen$$vJCNS$$x0 000188359 9131_ $$0G:(DE-HGF)POF2-451$$1G:(DE-HGF)POF2-450$$2G:(DE-HGF)POF2-400$$3G:(DE-HGF)POF2$$4G:(DE-HGF)POF$$aDE-HGF$$bSchlüsseltechnologien$$lBioSoft$$vSoft Matter Composites$$x1 000188359 920__ $$lyes 000188359 9201_ $$0I:(DE-Juel1)JCNS-1-20110106$$kNeutronenstreuung ; JCNS-1$$lNeutronenstreuung$$x0 000188359 9201_ $$0I:(DE-Juel1)JCNS-SNS-20110128$$kJCNS-SNS$$lJCNS-SNS$$x1 000188359 980__ $$ajournal 000188359 980__ $$aVDB 000188359 980__ $$aI:(DE-Juel1)JCNS-1-20110106 000188359 980__ $$aI:(DE-Juel1)JCNS-SNS-20110128 000188359 980__ $$aUNRESTRICTED 000188359 981__ $$aI:(DE-Juel1)JCNS-SNS-20110128