Isolation of a bismuth chloride-iron carbonyl adduct: synthesis and structural characterization of (PhCH2NMe3)2(Bi2Cl4(mu-Cl)2(mu-Fe(CO)4))

(PhCH2NMe3)2(Bi2Cl4(mu-Cl)2(mu-Fe(CO)4)) is prepared from BiCl3 and (PhCH2NMe3)2(Fe(CO)4). It exhibits a high degree of stability inspite of the presence of a nucleophilic iron carbonyl anion and BiCl3 as a lewis acid. The two BiCl3 groups are bridged by an (Fe(CO)4)2- moiety. The coordination geometry at Bi is square-pyramidal with two chloride ligands being shared between Bi-atoms whereas at Fe it is octahedral. The charge transfer from Fe-carbonyl group to Bi2Cl6 results in a delocalization of electron density over chloride ligands contributing towards the stability of the complex.