Redox flexibility of iron complexes supported by sulfur-based tris(o-methylenethiophenolato)amine relative to its tripodal oxygen-based congener
Por:
Mondragon, Alexander, Martinez-Alanis, Paulina R., Aullon, Gabriel, Hernandez-Ortega, Simon, Robles-Marin, Elvis, Flores-Alamo, Marcos, Ugalde-Saldivar, Victor M., Castillo, Ivan
Publicada:
1 ene 2016
Categoría:
Inorganic Chemistry
Resumen:
Tripodal ligands designed to generate a local C-3 symmetry have resulted
in novel types of metal complexes that feature unusual bonding and
electronic properties. However, most complexes reported to date are
characterised by strong field ligands that enforce low or
intermediate-spin states for the metal centres. Moreover, anionic
sulfur-based tripodal ligands are particularly scarce due to their
challenging synthesis. In this context, we herein report the synthesis,
spectral characterization, structural, and electronic properties of an
iron complex supported by the tripodal, trianionic ligand
[N(CH2ArS)(3)](3-) as the trigonal-bipyramidal complexes
[Fe{N(CH2ArS)(3)(X)] (1(X), X = DMSO, THF). The solid-state
structures reveal local C-3v symmetry around the Fe3+ ions, while
electron spin resonance measurements established a high-spin state (S =
5/2). Electrochemical studies demonstrate the redox flexibility of the
FeS3 fragment by direct comparison with the oxygen-based analogue
N(CH2ArOH)(3), which displays an irreversible reduction; in contrast,
1(THF) has a reversible Fe3+/Fe2+ redox process at -0.83 V (relative to
the ferrocenium/ferrocene redox couple). The high spin and redox
properties of 1(THF) are attributable to the weak ligand field provided
by the NS3 fragment, as confirmed by the electronic structure calculated
by density functional theory, which reveals substantial electronic
delocalisation and covalency of the Fe-S bonds in 1(X).
Filiaciones:
Mondragon, Alexander:
Univ Nacl Autonoma Mexico, Inst Quim, CU, Mexico City 04510, DF, Mexico
Martinez-Alanis, Paulina R.:
Univ Barcelona, Dept Quim Inorgan, Marti & Franques 1-11, Barcelona 08028, Spain
Univ Barcelona, Inst Quim Teor & Computac, Marti & Franques 1-11, Barcelona 08028, Spain
Aullon, Gabriel:
Univ Barcelona, Dept Quim Inorgan, Marti & Franques 1-11, Barcelona 08028, Spain
Univ Barcelona, Inst Quim Teor & Computac, Marti & Franques 1-11, Barcelona 08028, Spain
Hernandez-Ortega, Simon:
Univ Nacl Autonoma Mexico, Inst Quim, CU, Mexico City 04510, DF, Mexico
Robles-Marin, Elvis:
Univ Nacl Autonoma Mexico, Inst Quim, CU, Mexico City 04510, DF, Mexico
Flores-Alamo, Marcos:
Univ Nacl Autonoma Mexico, Fac Quim, Div Estudios Posgrad, Ciudad Univ, Mexico City 04510, DF, Mexico
Ugalde-Saldivar, Victor M.:
Univ Nacl Autonoma Mexico, Fac Quim, Div Estudios Posgrad, Ciudad Univ, Mexico City 04510, DF, Mexico
Castillo, Ivan:
Univ Nacl Autonoma Mexico, Inst Quim, CU, Mexico City 04510, DF, Mexico
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