A new class of electrically conducting organometallic salts with an unprecedented metallocene stack. Preparation and crystal structures of η5-cyclopentadienyl-η6-tri- and hexa-methylbenzeneiron(II) tetracyano-p-quinomethanides

Abstract

Redox reactions between [(cp)FeAr]⁺I^–(cp =η⁵-C₅H₅; Ar = 2,4,6-Me₃C₆H₃ or C₆Me₆; readily prepared from the parent PF₆ salts by exchange with Kl on anionic resin) and tetracyanoquinodimethane (TCNQ), afford electrically conducting, single crystals of the title compounds whose structures reveal, as a consequence of the difference in size of the two parallel planar ligands, one-dimensional segregated stacks of organometallic cations and TCNQ^½– anions, a situation unique in metallocene complexes with electron acceptors.