Photoaddition of Fe2S2(CO)6 to C60

Abstract

There is intense interest in the functionalization of the fullerenes, especially as these molecular allotropes of carbon become increasingly available. Metal complexes figure prominently in the array of reagents that attack the Cm, C70, and now c g 4 cages.' Fullerenes interact with metals most commonly via direct metal-cage bonding. Rarer are cases whereby the fullerene binds to ligands, the noteworthy examples are Hawkins' studies on the osmylation of Cm and c70.2 While not well developed, the ligand-based reactivity has the advantage of enhanced kinetic stability of the products and the potential for the decomplexation of modified fullerenes. The present work involves the reaction of c 6 0 with sulfido ligands; as such, it represents a continuation of our interest in carbon sulfide^.^ C -s g

Stereochemistry of alkylthioiron carbonyls and isovalent cyclopentadienylcobalt and benzeneiron derivatives

“…In every case the lowest energy structures are those with the two RS groups oriented in opposite directions (the ud isomers). This is in agreement with experimental work on the Fe 2 (CO) 6 (l-SCH 3 ) 2 system where the ud-e isomer is found to be the most abundant product from the reaction of Fe 3 (CO) 12 and dimethyl disulfide [2,4]. The other two possible stereoisomers, namely the uu and dd isomers, which both have equivalent RS groups, lie at somewhat higher relative energies.…”

“…The other two possible stereoisomers, namely the uu and dd isomers, which both have equivalent RS groups, lie at somewhat higher relative energies. The lower energy of these two isomers of Fe 2 (CO) 6 (l-SCH 3 ) 2 , namely the dd-e isomer, is found experimentally to be the minor product from the reaction of Fe 3 (CO) 12 with dimethyl disulfide [2,4]. Structures with central planar Fe 2 S 2 units and 180°S-FeFe-S dihedral angles are found for Fe 2 (CO) 6 (l-SR) 2 derivatives, but always at significantly higher energies than the butterfly structures, ranging from 21 to 29 kcal/mol above the global minima.…”

“…3 [9]. This diradical appears to be an intermediate in [2+2] cycloadditions of Fe 2 (CO) 6 (l-S) 2 with alkenes [10], alkynes [11], and fullerenes [12] as well as photochemical insertion of CO into the S-S bond [13]. The Fe 2 (CO) 6 (l-S) 2 diradical and its addition products have a central Fe 2 S 2 butterfly unit similar to that in the Fe 2 (CO) 6 (l-SR) 2 derivatives.…”

“…The chemistry of organosulfur metal carbonyl derivatives originated in 1937 with the discovery by Hieber and Spacu [1] of reactions between Fe 3 (CO) 12 and various sulfides, mercaptans, and disulfides to give stable red Fe 2 (CO) 6 (l-SR) 2 compounds. Originally the nature of these compounds was rather obscure since the possibility of direct metal-metal bonds in molecular polynuclear transition metal derivatives had not yet been recognized at the time of their original discovery.…”

Redox and “Antioxidant” Properties of Fe2(μ-SH)2(CO)4(PPh3)2

“…The monophosphine complex Fe 2 (μ-S 2 )(CO) 5 (PPh 3 ) (3) has been prepared previously. 22 Compound 2 is well-behaved in solution. A single isomer was observed by 31 P NMR spectroscopy.…”