s-Block Metal Complexes of the Bis(tetramethylcyclopentadienyl) Phosphonium Diylide [Me(<i>t</i>-Bu)P(C₅Me₄)₂]⁻

Treatment of the phosphonium salt [Me(t-Bu)P(C5Me4H)2]I with 2 equiv of KH produces the coordination polymer {K[Me(t-Bu)P(C5Me4)2](thf)}∞. If the phosphonium salt reacts with a single equivalent of KH followed by Ca[N(SiMe3)2]2, the calcium complex [Me(t-Bu)P(C5Me4)2]CaN(SiMe3)2 is produced, which is structurally related to Cp′2LnX organolanthanides. Density functional theory studies of the H3E (E = C, Si, P)-substituted cyclopentadienyl ring indicate that the energy required for out-of-plane bending of the substituent decreases in the order H3C > H3Si > H3P.