ქიმიის ტერმინთა განმარტებითი ლექსიკონი

Mesophase in which the long axes of the molecules are, on average, orientationally ordered about a common director and one of the shorter molecular axes is ordered, on average, about a second, orthogonal director.

Note 1: See Fig. for an illustration of the molecular arrangement in a N_b mesophase.

Note 2: From a crystallographic point of view, the biaxial nematic structure is characterised by the symbol D_2h in the Schoenflies notation (2/m, m in International System).

Note 3: In lyotropic systems, biaxial nematic mesophases have been identified from the biaxial symmetry of their tensorial properties.

Note 4: The situation for thermotropic calamitic systems is less clear and for some compounds claimed to form a N_b, detailed investigations have found the mesophase to be of type N_u.

Note 5: A biaxial nematic has the same structure as a disordered sanidic mesophase. it is recommended that the latter name be discontinued and the name biaxial nematic be used.

Fig. Schematic representation of a biaxial nematic mesophase.