Direct Synthesis of Pentaarylcyclopentadienyl Sandwich and Half-Sandwich Complexes of s-, p-, and d-Block Metals

Abstract

The sterically demanding pentaarylcyclopentadienyl radical CpBIGt-Bu• (1; CpBIGt-Bu = Cp(4-t-Bu-Ph)5) reacts with group 2, group 13, and group 14 metal amalgams to form the following complexes of the type CpBIGt-Bu2M (M = Ca (3), Sr (4), Ba (5)), CpBIGt-BuM′ (M′ = Ga (6), In (7), Tl (8)) and CpBIGt-Bu2M′′ (M′′ = Sn (10), Pb (11)). In addition, metallocenes CpBIG2Mg (2), CpBIG2Hg (12), and CpBIG2Ge (9) were formed in reactions of 1 with magnesium anthracene (2) and elemental mercury (12) as well as by salt metathesis between CpBIGt-BuK and GeCl2·dioxane (9). 6 was found to react with (coe)Cr(CO)5 (coe = cis-cyclooctene) with formation of CpBIGt-BuGaCr(CO)5 (13). 2–13 were characterized by elemental analysis and IR and NMR spectroscopy. In addition, the solid-state structures of 2, 4, 5, and 9–13 were determined by single-crystal X-ray diffraction.