[η⁵-(Phenylethynyl)cyclopentadienyl](η⁴-tetraphenylcyclobutadiene)cobalt(I)

Abstract

In the title compound, [Co(C13H9)(C28H20)], the Co atom is sandwiched between cyclo­penta­dienyl and cyclo­butadienyl rings that are inclined at a dihedral angle of 2.6 (3)°. The four phenyl rings are tilted with respect to the cyclo­butadienyl plane so that the C4Ph4 unit constitutes a four-bladed propeller. The phenyl ring of the phenyl-alkyne substituent is inclined to the cyclo­penta­dienyl ring at an angle of 34.92 (18)°. The crystal structure is stabilized solely by C—H⋯π inter­actions which generate a three-dimensional network.

The preparation, spectroscopy, structure and electrochemistry of some [Co(η4-C4Ph4)(η5-C5H4CC–CHY)], [Fe(η5-C5H5)(η5-C5H4CC–CHY)], and related complexes

“…We are confident of that for the C^CeCH]CHeC 5 H 4 -h 5 )Fe(h 5 -C 5 H 5 ) parts of both Z and E-9a but rather less so of that for the Co(h 4 -C 4 Ph 4 )(h 5 -C 5 H 4 e) end-group. However, assignments are consistent with related Cb 4 and Fc substituted alkene and alkyne systems [9,13,19].…”

“…As for the 1 H NMR spectrum, we are confident of the attribution and assignment of signals due to the (eC^CeCH]CHeC 5 H 4 -h 5 )Fe(h 5 -C 5 H 5 ) part of both Z and E-9a but less so of that for the Co(h 4 -C 4 Ph 4 )(h 5 -C 5 H 4 e) end-group. The chemical shifts of the various C atoms are comparable with those observed for similar compounds such as Cb 4 eC^CePh, FceC^CeR, Cb 4 eCH]CHeR and E-FceCH]CHeR (R ¼ aryl) [9,13,19].…”

“…For example, in the solid state the intensity of the n(C^C) band of [Cb 4 eC^CePh] [19] is ca. half of those due to the n(CeH)…”

“…Thus the method of Stevens and Richards was used to obtain [Cb 4 eCHO], 1a [16], and that of Rosenblum [21] [19]. Various spectroscopic details and the electrochemistry of this compound are discussed in the following sections with those of compounds 3e9.…”

Chemistry of the highly stable hindered cobalt sandwich compound (η5-Cp)Co(η4-C4Ph4) and its derivatives

“…McAdam and co-workers have synthesized [η 5 -by reaction of the lithiated salt of 45 with dimethylformamide followed by hydrolysis[52]. Compound 45 also undergoes Castro-Stephens coupling with iodobenzene in the presence of CuI and triethylamine to give 82 (Scheme 20)[64].Gleiter and coworkers have synthesized (η 5 -C 5 H 5 )Co(η 4 -C 4 Ph 4 ) units bridged by butadiyne, octatetrayne and dodecahexayne units (compound 87 -89) by using Hay coupling of various terminal alkyne derived cobalt sandwich compounds 45, 84 and 84 in the presence of cuprous chloride and pyridine/TMEDA under oxygen in good yields [51]. Terminal butadiyne and hexatriyne derivatives 83 and 84 were synthesized by using modified Cadiot-Chodkiewicz coupling between (triethylsilyl)ethynyl bromide and 45 and 83, respectively to give 85 and 86, respectively as shown in the (scheme 21).…”