Stepwise Reduction of Four Carbonyl Ligands in (η⁵-C₅H₄Me)₄Fe₄(μ₃-CO)₄ To Produce Clusters Containing μ₃-Methylidyne and/or Acetylene Ligands

Abstract

Treatment of (η5-C5H4Me)4Fe4(μ3-CO)4 with LiAlH4, followed by air-oxidation in the presence of NH4PF6, led to stepwise reduction of the four carbonyl ligands to afford [(η5-C5H4Me)4Fe4(μ3-CO)3(μ3-CH)](PF6), [(η5-C5H4Me)4Fe4(μ3-CO)2(μ3-CH)2](PF6)2, [(η5-C5H4Me)4Fe4(μ3-CO)(μ3-CH)(HCCH)](PF6), and [(η5-C5H4Me)4Fe4(HCCH)2](PF6). Two-electron reduction of [(η5-C5H4Me)4Fe4(μ3-CO)2(μ3-CH)2](PF6)2 resulted in coupling of two methylidyne ligands to form the acetylene-coordinated cluster (η5-C5H4Me)4Fe4(μ3-CO)2(HCCH), two-electron oxidation of which regenerated [(η5-C5H4Me)4Fe4(μ3-CO)2(μ3-CH)2](PF6)2. Further treatment of isolated (η5-C5H4Me)4Fe4(μ3-CO)2(HCCH) with LiAlH4 produced (η5-C5H4Me)4Fe4(HCCH)2. All clusters were fully characterized by X-ray diffraction studies.

Lewis Acid Chemistry of a Cationic [CCH] Subunit in a Bisdisphenoidal Eight-Atom Tetrairon–Tetracarbon Cluster

“…Coordination of acetonitrile to the cationic [CCH] subunit in [ 3 ](PF 6 ) 2 is facile, as indicated by NMR analysis (vide supra), and is not effective in compensating for the electron deficiency. The cluster [ 3 ](PF 6 ) 2 is extremely air-sensitive and quickly decomposed to form [(η 5 -C 5 H 4 Me) 4 Fe 4 (HCCH)(μ 3 -CO)(μ 3 -CH)] + ([ 5 ] + ) as a main product . To expand this chemistry, we have synthesized an easily accessible synthon for a donor-free [(η 5 -C 5 H 4 Me) 4 Fe 4 (HCCH)(HCC)] 2+ that can be handled by using standard Schlenk techniques.…”

Nonaqueous capillary gel electrophoretic analysis of metal nanoclusters in polymeric–DMSO–Li+ systems

“…Five tetrairon clusters (Fig. 1) were synthesized according to the previous reports [21][22][23]. BGEs were prepared by dissolving the polymers and lithium ions in DMSO at 60°C.…”

19 Organometallic chemistry of bi- and polymetallic complexes

“…Methylation of anionic 8 (with CF 3 SO 3 Me) gives the Fischer-carbene 11, whilst oxidation of 8 with [Cu(NCMe) 4 ]BF 4 results in abstraction of the organic ligand, giving 12 (Scheme 2). 39 Treatment of [Fe 40,41 Thermal reactions of PHPh 2 with [Fe 2 (CO) 4 Cp 2 ] give high yields of the phosphido-bridged complex trans-[Fe 2 (m-H)(m-PPh 2 )(CO) 2 Cp 2 ] (trans-13), which is a convenient scaffold through which to further investigate the photochemical and Scheme 1 thermal reactions of hydride-phosphide bridged iron complexes. 42 For example, low temperature photolysis of trans-13 gives the cis isomer, while photochemical reaction of 13 with secondary phosphines affords monocarbonyl species 14 via a hydride intermediate.…”