Methylthioirontricarbonyl dimer

Methylthioirontricarbonyl dimer
Names
	Other names Methanethiolatoirontricarbonyl dimer
Identifiers
CAS Number	14878-96-7;
3D model (JSmol)	Interactive image;
ECHA InfoCard	100.035.396
EC Number	238-952-6;
PubChem CID	6398988;
	InChI InChI=1S/6CO.2CH4S.2Fe/c81-2;;/h;;;;;;22H,1H3;;/p-2 Key: SPTHAIYODQFJDT-UHFFFAOYSA-L;
	SMILES O=C=[Fe](=C=O)(=C=O)12S(C)[Fe]1(=C=O)(=C=O)(=C=O)S2C;
Properties
Chemical formula	C8H6Fe2O6S2
Molar mass	373.94 g/mol
Appearance	red crystals
Melting point	65 °C (149 °F; 338 K) (isomer A), 102 °C (isomer B)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Methylthioirontricarbonyl dimer, also known as methanethiolatoirontricarbonyl dimer, is an organometallic compound with the formula Fe₂(SCH₃)₂(CO)₆. It is a red volatile solid that is classified as a transition metal thiolate complex. It exists as air-stable red crystals with two isomers, where the methyl groups are either anti (isomer A) or syn (isomer B) with respect to each other.^[1]

Synthesis

It was first synthesized 1940^[2] with the discovery of isomers in 1962.^[3] Synthesis involves treating triiron dodecacarbonyl with dimethyl disulfide:

2 Fe₃(CO)₁₂ + 3 (CH₃)₂S₂ → 3 [Fe(CO)₃SCH₃]₂ + 6 CO

It can be purified by recrystallization or by sublimation. The isomers can be separated by chromatography.

Structure

The methylthioirontricarbonyl dimer is a butterfly cluster compound, consisting of two iron atoms with distorted square pyramidal coordination geometry. The geometry is octahedral if the Fe-Fe bond is included. Each iron has three terminal carbon monoxide ligands and two bridging methylthiolate ligands. The Fe-Fe distance is 2.537 Å with an average Fe-S bond length of 2.259 Å. The average Fe-S-Fe bond angle is relatively small at 68.33°. Three isomers are possible but only the diequatorial and axial-equatorial isomers are seen. The diaxial isomer is disfavored due to steric hindrance.^[4]^[5] The structurally related compound [Fe(CO)₃S]₂ has idealized C_2v symmetry.

References

^ King, R. B. "Organometallic Synthesis, Volume 1: Transition-metal compounds" (1965) Academic Press. ISBN 0124080502
^ Hieber, W., Scharfenberg, C. "Einwirkung organischer Schwefelverbindungn auf die Carbonyle des Eisens" Chem. Ber. 1949, vol. 73, 1012. doi:10.1002/cber.19400730914
^ R. B. King (1962). "Organosulfur Derivatives of Metal Carbonyls. I. The Isolation of Two Isomeric Products in the Reaction of Triiron Dodecacarbonyl with Dimethyl Disulfide". J. Am. Chem. Soc. 84 (12): 2460. doi:10.1021/ja00871a045.
^ Dahl, L. F.; Wei, C. H. (1963). "Structure and Nature of Bonding of [C₂H₅SFe(CO)₃]₂". Inorg. Chem. 2 (2): 328. doi:10.1021/ic50006a022.
^ M. C. Ortega-Alfaro; N. Hernández; I. Cerna; J. G. López-Cortés; E. Gómez; R. A. Toscano; C. Alvarez-Toledano (2004). "Novel dinuclear iron(0) complexes from α,β-unsaturated ketones β-positioned with sulfide and sulfoxide groups". J. Organomet. Chem. 689 (5): 885–893. doi:10.1016/j.jorganchem.2003.12.015.

[1] King, R. B. "Organometallic Synthesis, Volume 1: Transition-metal compounds" (1965) Academic Press. ISBN 0124080502

[2] Hieber, W., Scharfenberg, C. "Einwirkung organischer Schwefelverbindungn auf die Carbonyle des Eisens" Chem. Ber. 1949, vol. 73, 1012. doi:10.1002/cber.19400730914

[3] R. B. King (1962). "Organosulfur Derivatives of Metal Carbonyls. I. The Isolation of Two Isomeric Products in the Reaction of Triiron Dodecacarbonyl with Dimethyl Disulfide". J. Am. Chem. Soc. 84 (12): 2460. doi:10.1021/ja00871a045.

[4] Dahl, L. F.; Wei, C. H. (1963). "Structure and Nature of Bonding of [C₂H₅SFe(CO)₃]₂". Inorg. Chem. 2 (2): 328. doi:10.1021/ic50006a022.

[5] M. C. Ortega-Alfaro; N. Hernández; I. Cerna; J. G. López-Cortés; E. Gómez; R. A. Toscano; C. Alvarez-Toledano (2004). "Novel dinuclear iron(0) complexes from α,β-unsaturated ketones β-positioned with sulfide and sulfoxide groups". J. Organomet. Chem. 689 (5): 885–893. doi:10.1016/j.jorganchem.2003.12.015.

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