Synthesis and structure of the mixed anion sandwich complex {[(C5H5)9Pb4]–[(C5H5)5Pb2]–[Li(12-crown-4)2]+2}

Abstract

The title compound, {[(C₅H₅)₉Pb₄]^–[(C₅H₅)₅Pb₂]^–[Li(12-crown-4)₂]⁺₂}1, is synthesised by the reaction of [(C₅H₅)₂Pb] and [(C₅H₅)Li] and 12-crown-4 (3:1:2 equiv. ), and is shown by X-ray diffraction to contain both a quintuple-decker and a triple-decker sandwich anión; in contrast, the corresponding reaction with [(C₅H₅)₂Sn](which possesses no such polymeric lattice of its own) in place of [(C₅H₅)₂Pb]_∞ yields the simple ‘paddlewheel’ molecule {[(C₅H₅)₃Sn]^–[Li(12-crown-4)₂]⁺}2.