Studies of Polyphenyls and Polyphenylenes. I. The Syntheses and Infrared and Electronic Spectra of Several Sexiphenyls

Seven linear sexiphenyls were synthesized by the Ullmann reaction of iodobiphenyl and diiodobiphenyl. Infrared studies indicated that the fine structure in the 780–810 cm−1 region suggests the presence of consecutive m-phenylene units, and that the positions of the strong or medium bands in the 820–840 cm−1 region indicate approximately the number of continuous p-phenylene units. The electronic spectra commonly displayed a prominent E-band in the narrow region of 192–207 nm. The intense K-band above 260 nm was considered to be an indication of the presence of one or more p-phenylene units.