Iron tris(dimethyldithiocarbamate) explained

Iron tris(dimethyldithiocarbamate) is the coordination complex of iron with dimethyldithiocarbamate with the formula Fe(S₂CNMe₂)₃ (Me = methyl). It is marketed as a fungicide.

Synthesis, structure, bonding

Iron tris(dithiocarbamate)s are typically are prepared by salt metathesis reactions.^[1]

Iron tris(dimethyldithiocarbamate) is an octahedral coordination complex of iron(III) with D₃ symmetry.^[2]

Spin crossover (SCO) was first observed in 1931 by Cambi et al. who discovered anomalous magnetic behavior for the tris(N,N-dialkyldithiocarbamatoiron(III) complexes.^[3] The spin states of these complexes are sensitive to the nature of the amine substituents.^[4]

Reactions

Iron tris(dithiocarbamate)s react with nitric oxide to give a nitrosyl complex:

This efficient chemical trapping reaction provides a means to detect NO.^[5]

Reflecting the strongly donating properties of dithiocarbamate ligands, iron tris(dithiocarbamate)s oxidize at relatively mild potentials to give isolable iron(IV) derivatives [Fe(S₂CNR₂)₃]⁺.^[6]

Iron tris(dithiocarbamate)s react with hydrochloric acid to give the pentacoordinate chloride:^[7]

Safety

The U.S. Occupational Safety and Health Administration (OSHA) has set the legal (permissible exposure limit) for ferbam exposure in the workplace as 15 mg/m³ over an 8-hour workday. The U.S. National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 1 mg/m³ over an 8-hour workday. At levels of 800 mg/m³, ferbam is immediately dangerous to life and health.

See also

• Zinc dimethyldithiocarbamate - a related dimethyldithiocarbamate complex of zinc
• Nickel bis(dimethyldithiocarbamate) - a related dimethyldithiocarbamate complex of nickel
• Iron tris(diethyldithiocarbamate) - a related dimethyldithiocarbamate complex of iron

Notes and References

1. The Chemistry of the Dithioacid and 1,1-Dithiolate Complexes. Progress in Inorganic Chemistry. 11. D. Coucouvanis. 2007 . 233–371. 10.1002/9780470166123.ch4. 978-0-470-16612-3 .
2. Compounds with intermediate spin. I. The crystal structure of tris(N,N-dimethyldithiocarbamato)iron(III) at 150 and 295 K. 1871–1877. 33. Acta Crystallographica Section B . J. Albertsson . Å. Oskarsson . 1977 . 6 . 10.1107/s0567740877007237.
3. L. Cambi . L and L. Szego . Chem. Ber. Dtsch. Ges.. 1931. 64. 2591. 10.1002/cber.19310641002. Über die magnetische Susceptibilität der komplexen Verbindungen. 10.
4. Book: P. Gütlich . H.A. Goodwin . Spin Crossover in Transition Metal Compounds I. Springer Berlin. 2004. 978-3-540-40396-8.
5. Fujii, S. . Yoshimura, T. . A New Trend in Iron–Dithiocarbamate Complexes: as an Endogenous NO Trapping Agent. Coordination Chemistry Reviews. 2000. 198. 89–99. 10.1016/S0010-8545(99)00196-4.
6. Pasek, E. A. . Straub, D. K. . Tris(N,N-Disubstituted Dithiocarbamato)iron(IV) Tetrafluoroborates. Inorganic Chemistry. 1972. 11. 2 . 259–263. 10.1021/ic50108a012.
7. 10.1021/ic50050a016. A Novel Series of fFive-Coordinated Iron(III) Complexes with the Square-Pyramidal Configuration and Spin, S = 3/2 . 1967 . Martin . R. L. . White . A. H. . Inorganic Chemistry . 6 . 4 . 712–717 .