High-resolution characterization of liquid-crystalline 60 fullerenes using solid-state nuclear magnetic resonance spectroscopy
2008 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 112, no 39, 12347-12353 p.Article in journal (Refereed) Published
Liquid-crystalline materials containing fullerenes are valuable in the development of supramolecular switches and in solar cell technology. In this study, we characterize the liquid-crystalline and dynamic properties of fullerene-containing thermotropic compounds using solid-state natural abundance C-13 NMR experiments under stationary and magic angle spinning sample conditions. Chemical shifts spectra were measured in isotropic, liquid-crystalline nematic and smectic A and crystalline phases using one-dimensional 13C experiments, while two-dimensional separated local-field experiments were used to measure the H-1-C-13 dipolar couplings in mesophases. Chemical shift and dipolar coupling parameters were used to characterize the structure and dynamics of the liquid-crystalline dyads. NMR data of fullerene-containing thermotropic liquid crystals are compared to that of basic mesogenic unit and mesomorphic promoter compounds. Our NMR results suggest that the fullerene-ferrocene dyads form highly dynamic liquid-crystalline phases in which molecules rotate fast around the symmetry axis on the characteristic NMR time scale of similar to 10(-1) s.
Place, publisher, year, edition, pages
2008. Vol. 112, no 39, 12347-12353 p.
IdentifiersURN: urn:nbn:se:kth:diva-17845DOI: 10.1021/jp803265zISI: 000259552000024ScopusID: 2-s2.0-54249086736OAI: oai:DiVA.org:kth-17845DiVA: diva2:335890
QC 201005252010-08-052010-08-05Bibliographically approved