Orientational order, molecular organization, and dynamics in mixtures of bent-core and rod-shaped mesogens: a 2H NMR study

Mixtures of a bent-core mesogen (ClPbis10BB) and a calamitic mesogen (6OO8), showing a nematic phase over the entire compositional range and one or two smectic phases (namely, SmA, SmC, or SmCA) below the nematic one over a wide concentration range, were investigated by means of H-2 NMR spectroscopy, exploiting selectively deuterated isotopomers of both mesogens. The analysis of H-2 NMR spectra recorded in the liquid crystalline phases on several representative mixtures gave information on the orientational order properties and the molecular organization within the phases as well as on the alignment properties upon application of a magnetic field. On the other hand, the analysis of H-2 longitudinal relaxation times (T-IZ and T-IQ) in 6OO8-d(2)/ClPbis10BB mixtures and pure 6OO8-d(2) allowed the influence of the bent-core mesogen on the dynamics of the calamitic one to be highlighted.