stretching mode of unconjugated olefins usually shows moderate to weak absorption at 1667–1640 cm 1. In samples, one small band, f, at 1648 cm 1 can be detected.
stretching mode of unconjugated olefins usuallyshows moderate to weak absorption at 1667–1640cm 1. In samples, one small band, f, at 1648 cm 1 canbe detected.