[Lithium tert-butylperoxide] : Crystal Structure of an Aggregated Oxenoid.

The X-ray crystal structure of the dodecameric lithium tert-butylperoxide [2] is the first of an alkali or alkaline earth peroxide. It shows the lithium ion bridging the two oxygen atoms of the peroxide unit and a slight lenghtening of the O-O bond, in agreement with quantum-chemical calculations. A calculation for the model reaction of MeLi with LiOOH to give MeOLi and LiOH reveals the importance of Li bridging the O-O bond in the transition state of this reaction, as similarly discussed for many oxidation reactions of (transition-) metal peroxides.