Self-assembly, molecular dynamics, and kinetics of structure formation in dipole-functionalized discotic liquid crystals.
The self-assembly, the molecular dynamics, and the kinetics of structure formation are studied in dipole-functionalized hexabenzocoronene (HBC) derivatives. Dipole substitution destabilizes the columnar crystalline phase except for the dimethoxy- and monoethynyl-substituted HBCs that undergo a reversible transformation to the crystalline phase. The disk dynamics are studied by dielectric spectroscopy and site-specific NMR techniques that provide both the time-scale and geometry of motion. Application of pressure results in the thermodynamic phase diagram that shows increasing stability of the crystalline phase at elevated pressures. Long-lived metastability was found during the transformation between the two phases. These results suggest new thermodynamic and kinetic pathways that favor the phase with the highest charge carrier mobility.
Elmahdy
Mahdy M
MM
Department of Physics, University of Ioannina, 451 10 Ioannina, Greece.
Dou
Xi
X
Mondeshki
Mihail
M
Floudas
George
G
Butt
Hans-Jürgen
HJ
Spiess
Hans W
HW
Müllen
Klaus
K