CPL: Ronald Dong: 13C tensors in mesogens, SUPER sequence

Nice extraction of 13C tensors in a complicated system.

Chemical Physics Letters
Volume 417, Issues 4-6 , 10 January 2006, Pages 475-479

On the carbon-13 chemical shift tensors of bent-core mesogens

Ronald Y. Dong a, b, J. Zhanga and K. Fodor-Csorbac

aDepartment of Physics and Astronomy, University of Manitoba, Winnipeg, Man., Canada R3T 2N2
bDepartment of Physics and Astronomy, Brandon University, Brandon, Man., Canada R7A 6A9
cResearch Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, 1525 Budapest, Hungary

Abstract

Solid state NMR techniques are used to study bent-shape achiral molecules which can form a new type of mesophases, known as ‘banana’ or B phases. In particular, a recent method called SUPER is applied to two solids of this type of polar mesogens, rotating at the magic angle, to extract carbon-13 chemical shift anisotropy tensors. They are useful not only to aid 13C peak assignments in the isotropic state, but are necessary for accounting the observed chemical shifts of various carbon sites, resided on the bent-core aromatic part, in the spectrum of an aligned mesophase. An example to extract ordering information is given for one of the studied mesogens.