Binuclear cyclooctatetraene–iron carbonyl complexes: examples of fluxionality and valence tautomerism

Abstract

Fluxionality and valence tautomerism are studied in the experimentally observedtrans-(η4,η4-C8H8)Fe2(CO)6,cis-(η3,η3-C8H8)Fe2(CO)6, andcis-C8H8Fe2(CO)4(μ-CO) structures using density functional theory.

Room Temperature Magnetic Switchability Assisted by Hysteretic Valence Tautomerism in a Layered Two-Dimensional Manganese-Radical Coordination Framework

“…In this redox process, the Co­(III) ion is reduced to Co­(II) and the CAT ligand is oxidized to its semiquinonato (SQ) form. VT transitions involving SQ-CAT ligand are by far the most reported in the literature, mainly in Co, − and Mn isolated complexes, − but also in various d block elements such as Fe, Ni, Rh, and V. − VT transitions were also observed in four unidimensional (1D) polymers and one Co-based bidimensional (2D) coordination polymer. ,− Other ligands than SQ-CAT are less common in VT systems, with a dozen examples reported so far, involving porphyrin derivatives, cyclopentadienyl, or bis­(diisopropyl-phenylimino)­acenaphthene. − In the latter case, VT was reported for Yb …”

The hapticity of the acenaphthylene ligand in its mononuclear, binuclear, and trinuclear iron carbonyl complexes

“…However, Gusev recently 11 demonstrated that the newer M06-L functional is a good-quality and relatively fast local density functional for computational work in organometallic chemistry and catalysis. The M06-L functional has been tested in our recent work, 10,12 which gives satisfactory performance in both speed and accuracy. For this reason, the M06-L method 13 as well as the previously used B3LYP 14,15 and BP86 16,17 methods were used in this work.…”