Journal of Chemical Physics, Vol.119, No.1, 413-422, 2003
Molecular structure and order of hexaoctyloxy-rufigallol in the solid and columnar phases: Analysis of H-2-C-13 dipolar and C-13 chemical-shift interactions
We report a C-13 NMR investigation of 1,2,3,5,6,7-hexaoctyloxy-rufigallol in the solid and columnar phases using various H-2- and C-13-labeled isotopomers. The measurements were performed under both static and magic-angle spinning conditions. The conformations of the aliphatic side chains were derived from an analysis of H-2-C-13 dipolar and C-13 chemical-shift interactions. The nonequivalent chains exhibit significantly different structural behavior in both solid and columnar phase. It emerged that one of the side chains adopts an in-plane structure, while the other two chains prefer antiparallel out-of-plane conformations. Quantum-chemical calculations of the C-13 chemical-shift tensors were also carried out. These calculations support the experimental findings. (C) 2003 American Institute of Physics.