The statistical principle of maximum entropy is applied to the analysis of dipolar couplings from H-1 NMR of nonrigid molecules dissolved in liquid-crystalline phases. A distribution function for the orientational and inter-ring angles is so obtained. The most probable internal angle phi is determined for 4,4'-dichlorobiphenyl (phi = 34-degrees) in the nematic phase of I52, 4-pentyl-4'-cyanobiphenyl (phi = 32-degrees) and 4'-Br-4-Cl-2,6-difluorobiphenyl (phi = 42-degrees) in EBBA. The physical reliability of the distributions determined is discussed. The maximum-entropy treatment seems to indicate a limit for the information on the internal motion obtainable from the experimental data.
|Autori:||CATALANO D.; DI BARI L; VERACINI C.A.; SHILSTONE G.N.; ZANNONI C.|
|Titolo:||A maximum-entropy approach analysis of the problem of the rotameric distribution for substituted biphenyls studied by 1H nuclear magnetic resonance spectroscopy in nematic liquid crystals|
|Anno del prodotto:||1991|
|Digital Object Identifier (DOI):||10.1063/1.460669|
|Appare nelle tipologie:||1.1 Articolo in rivista|