Date of Award
Organoiron compounds, Carbonyl compounds, Sulfur bonding
Doctor of Philosophy (PhD)
C. Max Hull
John J. Eisch
The first examples of sulfur-donor ligand ortho-metallated complexes were obtained in good to excellent yields by reaction of various thiobenzophenones and a thiobenzoate with diiron enneacarbonyl in benzene at room temperature. The known trinuclear complex S2Fe3(CO)9 was a by-product of these reactions, and complexes of the type (Ar2C)S2Fe2(CO)6 were formed in several instances. The structures of these complexes were established on the basis of microanalytical and spectral data as well as by reductive cleavage experiments. Oxidative or photolytic cleavage of the ortho-metallated complexes provides a convenient entry to the little known isobenzothiophene system. The heteroatom has an important effect on the ortho-metallation reaction. Mechanisms are postulated for formation of the organometallic complexes.
Fully substituted thioureas and thioamides react with Fe2(CO)9 at room temperature to give sulfur-donor ligand iron tetracarbonyl complexes, diiron hexacarbonyl complexes having both nitrogen and sulfur donor ligands, and the known S2Fe3(CO)9. Tetramethylthiourea rather than carbonyl ligand displacement occurred on treatment of tetramethylthioureairon tetracarbonyl with tri-n-butylphosphine. Thioureairon tetracarbonyls, bis(thiourea) iron tricarbonyls, as well as triiron octacarbonyl complexes (nitrogen and sulfur donor ligands) were obtained from reactions of disubstituted and trisubstituted thioureas with Fe2(CO)9. Thiobenzanilide and 5-methyl-3-phenyl-2-thiohydantoin gave similar complexes.
The major product (71.5% yield) obtained from reaction of adamantanethione and diiron enneacarbonyl was C16H14S2Fe2O6, which contains bridging and terminal carbonyl groups, as well as two sulfur atoms attached to the same carbon atom. By-products of the reaction were an isomeric complex lacking bridging carbonyls but possessing a carbon-iron sigma bond; and dimeric complexes of formula C26H28S2Fe2O6, differing by the presence or absence of bridging carbonyls. The major product was easily converted to an isomeric, non-bridging carbonyl complex still having a sulfur-carbon-sulfur linkage. Reductive cleavage of these complexes afforded adamantanone or a disulfide, subject to the nature of the complex. While treatment of thiocamphenilone with Fe2(CO)9 gave complexes analogous to those obtained from adamantanethione [S2Fe3(CO)9 was also formed], only sulfur-iron carbonyls were produced using thiofenchone as the reactant thioketone.
Chan, Albert Shil-Kwan, "Synthesis and chemistry of thione-iron carbonyl complexes" (1973). Graduate Dissertations and Theses. 188.