... Volume: Page ... 1 (film), 15 a value not far from cyclohexanone (1712 cm - 1 ) 16 and the bicyclics 4a−c (1710−1720 cm - 1 ). 2,2,6,6 ... to absorb at 1766 cm - 1 . 16 However, in the carbonyl region of the IR spectrum of the tetrachlorinated bicyclics 3 two bands occur ...