Synthesis and Structure of [Mg(dmso)6]2+[C5H5]-2 and [Mg(η1-C5H5)(η5-C5H5)(thf)2] (dmso = dimethylsulfoxide, thf = tetrahydrofuran)

Dicyclopentadienylmagnesium, Mg(C5H4)(2), reacts with dimethyl sulfoxide, dmso, to afford the ionic compound [Mg(dmso)(6)](2+)[C5H5](-)(2) with naked uncoordinated cyclopentadienyl rings; the reaction of Mg(C5H2)(2) with tetrahydrofuran, thf, leads to the neutral complex [Mg(C5H5)(2)(thf)(2)] with an eta(1)- and eta(5)-coordinated cyclopentadienyl ring.