Structure of mesogens possessing B7 textures: the case of the bent-core mesogen 8-OPIMB-NO2.
A structural investigation of the compound 8-OPIMB-NO2 is carried out. This material is a mesogen formed by bent-core molecules where the so-called B7 phase was originally proposed. X-ray data are successfully indexed in terms of a oblique two-dimensional lattice. Using additional information from optical second harmonic generation several possible structural models are proposed. The models are based on molecular packing considerations. All these structures are clearly different from those of other materials previously classified as B7. The necessity of a revised nomenclature for classifying the structures of these compounds is pointed out.
Folcia
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Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad del País Vasco, Apartado 644, 48080 Bilbao, Spain.
Etxebarria
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J
Ortega
J
J
Ros
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MB