The electronic absorption spectra and molecular aggregate formation in vacuum deposited films of mesogenic cyanobiphenyls and their solutions

Electronic absorption spectra of mesogenic 4-pentyl-4 ' -cyanobiphenyl (5CB ), 4-octyl-4 ' cyanobiphenyl (8CB) and 4-octyloxy- 4 ' -cyanobiphenyl (8OCB ) films produced by cyanobiphenyl molecular vapor deposition were measured. The appearance of the spectral changes during annealing and dissolution of cyanobiphenyl film samples are discussed assuming molecular dimerization a nd H-aggregate formation.