Studies on the synthesis, spectra and structure of isomerized products of isopentadiene(dicarbonyl)-[ethoxy(aryl)carbene]iron complexes and the crystal structure of tetracarbonyl[ethoxy-(pentachlorophenyl)carbene]iron

Abstract

Reaction of π-isopentadienetricarbonyliron (1) with aryl lithium ArLi (Arphenyl, p-tolyl, p-methoxyphenyl, p-trifluoromethylphenyl) in ether at low temperature, and subsequent alkylation of the acylmetallate formed with triethyloxonium tetrafluoroborate[(C2H5)3OBF4] in aqueous solution at 0°C, gave orange-red crystalline complexes (2-5), the isomerized products of isopentadiene (dicarbonyl) [ethoxy(aryl)carbene] iron with composition of C5H8 (CO)2FeC(OC2H5)Ar When LiC6Cl5 was used as nucleophilic reagent in the reaction, on alkylation of the afforded acylmetallate intermediate under some reaction conditions, complex (CO)4FeC(OC2H5)C6Cl5 (6) was obtained. The molecular structure of complexes 2 and 6 were determined by means of single crystal X-ray diffraction measurements. IR, 1H NMR and mass spectra of these complexes were investigated.