Vibrational study of short-range order and structure of polyaniline bases and salts

Raman and infrared reflection spectra in the backbone deformations and latt ice modes range (10-1000 cm(-1)) of EB/ES-I and EB/ES-II polyanilines are d iscussed and compared with those of an oligomer (BQBBa) and of the constitu tive bricks of the polyaniline skeleton: diphenylamine (BQB), N,N-'diphenyl -1,4-phenylenediamine (BBB), and N,N'-diphenyl-1,4-phenylenediimine (BQB). Short-range structure, scaling motif, and disorder are discussed. Emphasis is given to the relationship between hybridization, short-range structure, disorder, and optical properties. Ring, CH deformations, and librational/tr anslational modes appear very sensitive to the static and dynamic disorder. Results show that vibrational spectroscopy allows to distinguish the two c lasses of polyaniline (ES-I and ES-II), whatever the inserted anion. The sk etch of a continuous change of angle between the rigid virtual N-ring-N bon d is proposed to describe the static orientational disorder.