Similar to studies with Sm 2+ , the introduction of oxygen to this system rapidly oxidizes the divalent species to [Cf(18-crown-6)x] 3+ . The solution absorption spectrum obtained following this color change shows that the low energy features exhibited by the reduced species in acetonitrile are notably absent, and a broad, intense feature is observed at 27,758 cm -1 (360 nm) instead. This latter feature is comparable to the high energy transition displayed by [Cf(18-crown-6)(H2O)2-