Mono- and bi-iron chalcogenocarboxylate complexes

Abstract

A series of thiocarboxylato and selenocarboxylato monomeric CpFe(CO)2ECORCOCl and dimeric [CpFe(CO)2ECO]2R iron complexes have been synthesized and characterized. The interaction of (μ-Ex)[CpFe(CO)2]2 (E = S; x = 2–4. E = Se; x = 1) with di-acid chlorides (ClCORCOCl) in a 1:1 molar ratio gave the monomeric complexes CpFe(CO)2ECORCOCl for R = 1,3-C6H4, 2,6-C5H3N, 1,2-C6H4. However, the dimeric complexes [CpFe(CO)2ECO]2R were obtained from the same reactants in a 2:1 metal-to-ligand molar ratio in which R is 1,3-C6H4, 2,6-C5H3N or C2H4. The monomer versus dimer production mainly depends on the electronic and steric factors of the R-moiety. The new monomeric and dimeric thio- and selenocarboxylato iron complexes have been characterized by spectroscopic techniques (1H- and 13C-NMR, IR) and by elemental analysis. The structures of [CpFe(CO)2SCO]2(1,3-C6H4) and its seleno analogue [CpFe(CO)2SeCO]2(1,3-C6H4) were determined by X-ray structure determination.