Bulletin of the Chemical Society of Japan · 1991 · 20 citations · 10 references
Natural SciencesChemistryCrystal StructureInorganic ChemistryOrganic ChemistryCrystal ChemistryCrystal SymmetryCrystallographyLiquid CrystalsMolecular StructureStructure DeterminationCrystal Structure DeterminationCrystallographic CharacterizationMolecular CrystallographyMolecular Structure DeterminationNematic Liquid CrystalsTriclinic SystemTriclinic Unit CellsUnit Cell Geometry
Abstract The crystal and molecular structure of the title nematogen (1), has been determined by an X-ray analysis. Compound 1 belongs to the triclinic system with space group P-1, a=9.798(2), b=11.579(2), c=9.716(2) Å, α=74.081(13), β=117.766(14), γ=108.179(13)°, and with two molecules in the unit cell. The geometry around the boron atom is planar, and the plane defined by O2BC is parallel to the phenyl ring bonded to the boron atom. The angle between two phenyl rings is 74.3°. The molecules are in their most extended conformation, with nearest neighbors oriented antiparallel to each other. The 1H NMR studies have indicated that the half-chair conformation of the dioxaborinane is kept in a solution even at 125°C where 1 forms a nematic phase, and the rigidity is essential for the formation of mesophases.
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