Photochemical and thermal decomposition of hydridotetracarbonylcobalt(I). Evidence for a radical pathway involving octacarbonyldicobalt

Wegman, R. W.; Brown, Theodore L.

doi:10.1021/ja00527a077

Cited by 52 publications

(26 citation statements)

References 3 publications

(3 reference statements)

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“…56 It was proved that the hydrogenation of Co 2 (CO) 8 follows an associative pathway affording 2 molecules of HCo(CO) 4 and the reaction takes place via a radical pathway involving cCo(CO) 4 . 57,58 Bursten 62 and obtained a notably higher value for the Co-Co bond dissociation enthalpy (29.9 kcal mol À1 ) than the experimental BDE (19 AE 2 kcal mol À1 ) reported by Klingler and Rathke. 63,64 The electronic and molecular structure of the coordinatively saturated and unsaturated hydrido cobalt carbonyls were investigated by Ziegler and co-workers at the BP86 level of theory in combination with an STO triple-z basis set.…”

Section: Generation Of the Active Catalystmentioning

confidence: 73%

Computational aspects of hydroformylation

Kégl

2015

RSC Adv.

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The influence of transition metal complexes as catalysts upon the activity and selectivity of hydroformylation reactions has been extensively investigated during the last decades. Nowadays computational chemistry is an indispensable tool for elucidation of reaction mechanisms and for understanding the various aspects which govern the outcome of catalytic reactions. This review attempts to survey the recent literature concerning computational studies on hydroformylation and theoretical coordination chemistry results related to hydroformylation.

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Section: Generation Of the Active Catalystmentioning

confidence: 73%

Computational aspects of hydroformylation

Kégl

2015

RSC Adv.

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“…Mirbach et al addressed this difficulty by photolytically generating [Co(CO) 4 ] under hydroformylation conditions . They concluded that [Co(CO) 4 ] does not react with H 2 , and Co 2 (CO) 8 directly reacts with H 2 to form [HCo(CO) 4 ] (Figure B). ,, However, this study is less conclusive as [HCo(CO) 4 ] decomposes under the photolytic conditions used. , Another difficulty associated with the study of the termolecular mechanism is that associative bimolecular H 2 activation by [Co(L)(CO) 3 ] 2 and termolecular H 2 activation by [Co(L)(CO) 3 ] (L = CO or PR 3 ) are kinetically indistinguishable due to the fast equilibrium between these complexes (Figure , rate expressions). , A kinetic study with isolated [Co(L)(CO) 3 ] is an ideal method to distinguish these mechanisms. Several isolable mononuclear Co(0) radicals are known .…”

Section: Introductionmentioning

confidence: 85%

[Co(NHC)(CO)₃]: Isolation and Reactivity Study of a Model 17-Electron Species in the Oxo Process

Takebayashi

Fayzullin

2021

Organometallics

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Metrics & MoreArticle Recommendations * sı Supporting InformationABSTRACT: [Co(L)(CO) 3 ] 2 (L = CO or PR 3 ) catalyzed hydroformylation of olefins is among the most successful homogeneous organometallic catalysis. The bimetallic [Co(L)(CO) 3 ] 2 complex exists in equilibrium with its mononuclear 17electron [Co(L)(CO) 3 ] metalloradical. However, isolation of the mononuclear metalloradical is unknown, and hence the role of this species in the catalytic cycle is difficult to study. Herein, we report the isolation of [Co(L)(CO) 3 ] using ringexpanded N-heterocyclic carbene (reNHC) ligands. Isolation of this complex enabled us to examine feasibility of putative termolecular H 2 activation by the [Co(L)(CO) 3 ] metalloradicals. The kinetic experiments revealed that [Co(reNHC)(CO) 3 ] does not activate H 2 via a previously proposed termolecular mechanism but via a bimolecular mechanism. The result obtained here will contribute to design a cobalt carbonyl complex that activates H 2 under mild conditions and to develop a more energy efficient oxo process based on economical cobalt catalysts.

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“…And at higher CO pressures, it is more likely to proceed through a radical species, namely . Co(CO) 4 , arising from the endothermic homolytic cleavage of the metal‐metal bond of Co 2 (CO) 8 [23c] . Thus, we deduce that owing to the relatively weak Lewis‐basicity of thietane substrate, the thietane‐ promoted disproportionation of Co 2 (CO) 8 to [Co(CO) 4 ] − and cationic cobalt(II) species staring from the dissociation of bridging carbonyl ligand could be inhibited under high CO pressure.…”

Section: Methodsmentioning

confidence: 85%

Dual Roles of Co₂(CO)₈ Enable Carbonylative Ring Expansion of Thietane under Ambient CO Pressure

et al. 2021

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Cobalt-catalyzed carbonylative ring expansion of thietane under ambient CO pressure was developed, affording a variety of thioacetones in moderate to high yields. dual roles of Co 2 (CO) 8 as the precursor of both carbonylation catalyst and Lewis acid was revealed by control experiments and spectroscopic characterization. The carbonylative ring expansion under CO gas-free conditions was demonstrated by using Co 2 (CO) 8 as both CO surrogate and pre-catalyst.

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Photochemical and thermal decomposition of hydridotetracarbonylcobalt(I). Evidence for a radical pathway involving octacarbonyldicobalt

Cited by 52 publications

References 3 publications

Computational aspects of hydroformylation

Computational aspects of hydroformylation

[Co(NHC)(CO)₃]: Isolation and Reactivity Study of a Model 17-Electron Species in the Oxo Process

Dual Roles of Co₂(CO)₈ Enable Carbonylative Ring Expansion of Thietane under Ambient CO Pressure

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Photochemical and thermal decomposition of hydridotetracarbonylcobalt(I). Evidence for a radical pathway involving octacarbonyldicobalt

Cited by 52 publications

References 3 publications

Computational aspects of hydroformylation

Computational aspects of hydroformylation

[Co(NHC)(CO)3]: Isolation and Reactivity Study of a Model 17-Electron Species in the Oxo Process

Dual Roles of Co2(CO)8 Enable Carbonylative Ring Expansion of Thietane under Ambient CO Pressure

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Resources

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[Co(NHC)(CO)₃]: Isolation and Reactivity Study of a Model 17-Electron Species in the Oxo Process

Dual Roles of Co₂(CO)₈ Enable Carbonylative Ring Expansion of Thietane under Ambient CO Pressure