1. Biphenyl (11) appears to be the active ?carrier?. The reactions described proceed approximately as fast in the presence of (11) alone under otherwise identical conditions: however, reactio of lithium with (11) alone does not start easily in DMM. They also seem to occur in the presence of naphthalene alone, but are then much slower small amounts of stable (3) can be detected. In the absence of (11) and of naphthalene no detectable reaction takes place. Action of Li on (11) in aprotic donor solvents such as DMM affords solutions containing equilibrium mixtures of biphenyllithium (12), and possibly also biphenyldilithium (13) with (11) and lithium.
2. Alkali metal additions to unsaturated systems
3. Reactions of the radical anions and dianions of aromatic hydrocarbons
4. Metal-ammonia reduction. XII. Mechanism of reduction and reductive alkylation of aromatic hydrocarbons
5. At present we consider two mechanisms formulated for (11) as the carrier: (1) (12) and/or (13) transfer electrons and lithium cations to ethylene [see : Carbanions. Living Polymers, and Electron Transfer Processes. Wiley-Interscience. New York 1968].