Visible absorption spectrum of liquid ethylene

The visible absorption spectrum of liquid ethylene at approximately 108 K from 5500 A to 7200 A was measured by using a pulsed tunable dye laser, immersed-transducer, gated-detection opto-acoustic spectroscopy technique. The absorption features show the strongest band with an absorption coefficient of approximately 2 x 10(-2) cm(-1) and the weakest band with an absorption coefficient of approximately 1 x 10(-4) cm(-1). Proposed assignments of the observed absorption peaks involve combinations of overtones of local and normal modes of vibration of ethylene.