Structural Information on the Transition Moments in Poly(ethylene‐2,6‐naphthalene) by Polarization FT‐IR Spectroscopy

Oriented poly(ethylene‐2,6‐naphthalate) (PEN) has been characterised by polarised FT‐IR spectroscopy to determine the structural angles of the transition moments to the molecular chain axis. The bands at 1130 cm−1, 1142 cm−1and 1602 cm−1, which have been previously assigned as having their transition dipole moments parallel to the chain axis, are confirmed as parallel bands. Bands at 767 cm−1and 831 cm−1are confirmed as perpendicular bands. However the band at 1708 cm−1which has previously been assigned as a perpendicular band, is shown here to have its transition moment at 72° to the molecular axis.