Details

Autor(en) / Beteiligte

• Patricia Cullen, E.
• Doherty, John
• Manning, A.R.
• McArdle, Patrick
• Cunningham, Desmond

Titel

Preparation, spectra, and fluxional behaviour of cyclopentadienylcobalt(III) complexes with dithiocarbamate and xanthate ligands. The crystal structure of [Co(η-C 5H 5)(I)(S 2CNEt 2)]

Ist Teil von

• Journal of organometallic chemistry, 1988-06, Vol.348 (1), p.109-122

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

1988

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• The reactions of [Co(η-C 5H 5)(CO) 2] with thiuram disulphides, [(R 2NCS 2) 2], give [Co(η-C 5H 5)(S 2CNR 2) 2], but it is better to use [Co(η-C 5H 5)(I)(η 2-S 2CNR 2)] (I), [Co(η-C 5H 5)(I)(η 2-S 2COR)](II), and their C 5H 4Me analogues, as precursors for [Co(η-C 5H 5)(η 1-S 2CNR 2)(η 2-S 2CNR 2)] (III), [Co(η-C 5H 5)(η 1-S 2CNR′ 2) (η 2-S 2CNR′ 2)l (IV), [Co(η-C 5H 5)(η 1-S 2COR)(η 2-S 2CNR′ 2)] (V), and [Co(η-C 5H 5)(η 1-S 2COR)(η 2-S 2COR′)] (VI) (R,R′ = Me or Et). The IR and 1H NMR spectra of I-VI are reported and assigned. They are consistent with structures that have pseudo-octahedral coordination about Co and planar CO(η 1-S∼S) and CO(η 2-S∼S) moieties where S∼S are dithiocarbamate or xanthate ligands. The various fluxional processes undergone by these complexes have been investigated by dynamic 1H NMR spectroscopy. There is rotation about CNEt 2 in η 2-S 2CNEt 2 ligands and C-NR 2 in η 1-dithiocarbamate ligands which can be slowed at low temperatures for I, III, IV and V, but rotation about COEt is always fast for η 2-S 2COEt ligands in II and VI. Both III and IV undergo η 1-η 2 ligand exchange but V and VI do not. In solution IV exists as a mixture of the two possible isomers with [CO(η-C 5H 5)(η 1-S 2CNMe 2)(η 2-S 2CNEt 2)] favoured at higher temperatures. An X-ray diffraction study confirms the pseudo-octahedral structure of [Co(η-C 5H 5)(I)(η 2-S 2CNEt 2)] with its planar diethyldithiocarbamate ligand.