The spectra, structures and electrochemistry of Ni(η5-C5H5)(PPh3)–CC–Ar complexes, and their reactions with Co2(CO)8

Stilbene analogues incorporating the Co(η4-C4Ph4)(η5-C5H4-) end group

“…0.2 V difference in E o between E and Z isomers, but when X is the electron-donating OMe group there is a cathodic shift of the redox couple to 0.87 V (E4b) and 0.89 V (Z-4b) and a quasi-reversible oxidation of the methoxyphenyl group is observed at 1.14 V. On the other hand, when X is the electron-withdrawing NO 2 group there is a predictable anodic shift of the [Co] þ/0 redox couple to 0.99 V for E-4d and 1.01 V for Z-4d. The electrochemistry of the 1-naphthyl complex E4e is very similar to that of E-4a; this is to be expected by comparisons with the electrochemistry of [Fe(h 5 -C 5 H 5 )(h 5 -C 5 H 4 CH]CHR)] [7] and [Ni(h 5 -C 5 H 5 )ChC-R] [47] where R is an aryl group. The pyrenyl analogue E-4g exhibits both the reversible [Co] þ/0 and a quasi-reversible pyrenyl redox couple at 0.88 V and 1.10 V respectively.…”

Synthesis, photochemistry, and electrochemistry of ruthenium(II) polypyridyl complexes anchored by dicobalt carbonyl units

“…), are particularly intriguing not only because of their unique structures but also because of their potential use as catalysts [8][9][10][11][12]. To the best of our knowledge, however, the photophysical characteristics of these M-Co 2 complexes and clusters have not been well explored, although electrochemical studies have been done on several of these complexes [11][12][13][14].…”

(Di‐tert‐butylphosphanylethyl)cyclopentadienylnickel Chelates with Alkyl, Alkenyl, Aryl, and Alkynyl Ligands: Hints to Cumulenylidene Resonance Forms

“…Such complexes are important in the context of the Pauson–Khand reaction, in which coupling of the alkyne with an alkene results, after CO insertion, in valuable cyclopentenones . Manning et al reported the syntheses of some nonchelate cyclopentadienyl triphenylphosphane alkynyl nickel complexes and performed reactions with dicobaltoctacarbonyl resulting in the formation of trimetallic alkyne hexacarbonyldicobalt complexes with a nickel substituent at the coordinated triple bond , . They mentioned that the parent compound with the unsubstituted alkynyl ligand coordinated to Co 2 (CO) 6 rapidly decomposed, so that only an IR spectrum could be measured for characterization.…”