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The magnetic properties and multi-electron reductive reactivity of the bimetallic inverse sandwich La2+complex salt, [K(18-crown-6)(THF)2][(Cp″2La)2(μ-η6:η6-C6H6)]·THF, 1(Cp′′ = C5H3(SiMe3)2), originally described by Lappert et al., have been examined. The compound was prepared by reduction of Cp″3La with potassium metal in benzene and crystallographically characterized. Compound 1can be described as containing two 5d1La(II) ions bridged by a planar (C6H6)1–benzenide bridged radical monoanion, with fits to its variable-temperature magnetic susceptibility data revealing strong antiferromagnetic exchange coupling, with JLa–C6H6> |−400 cm–1|. The multi-electron reduction reactivity of 1was explored in reactions with anthracene, naphthalene, and cyclooctatetraene. Compound 1reduces anthracene to give Cp″2La(μ-η6:η6-C14H10)K(18-crown-6), 2, which contains a nonplanar anthracenide dianion with an end ring interacting with La(III) and the central ring interacting with potassium. The reaction of 1with naphthalene forms [K(18-crown-6)(THF)2][Cp″2La(η4-C10H8)], 3, which has a naphthalenide dianion with one planar ring and one ring bent such that four carbons atoms have 2.663(4)–2.743(4) Å La–C distances. 1,3,5,7-Cyclooctatetraene is reduced by 1to give the bridged cyclooctatetraenyl complex salt [K(18-crown-6)][(μ-η8:η2-C8H8)LaCp″(μ-η8:η8-C8H8)LaCp″2], 4.