Synthesis and chemistry of thione-iron carbonyl complexes

Author

Albert Shil-Kwan Chan, Binghamton University--SUNY

Alternate Author Name(s)

Dr. Albert Chan, PhD '74

Document Type

Dissertation

Date of Award

1973

Keywords

Organoiron compounds, Carbonyl compounds, Sulfur bonding

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

C. Max Hull

Second Advisor

John J. Eisch

Third Advisor

Howard Alper

Abstract

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.

Recommended Citation

Chan, Albert Shil-Kwan, "Synthesis and chemistry of thione-iron carbonyl complexes" (1973). Graduate Dissertations and Theses. 188.
https://orb.binghamton.edu/dissertation_and_theses/188