Computational QM/MM study on the structure and energetics of species involved in the activation of the C–H and C–S bonds of thiophene by Cp*RhPMe<sub>3</sub>

Maresca, Olivier; Maseras, Feliu; Lledós, Agustı́

doi:10.1039/b311926b

Cited by 23 publications

(9 citation statements)

References 58 publications

(68 reference statements)

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“…[60,61] The interaction energy at the hydride site remains almost unchanged, showing that the electronic effect of the phenyl substituents is also small. The results at the metal site contrast with those at the hydride site.…”

Section: Full Papermentioning

confidence: 99%

Experimental and Computational Studies of Hydrogen Bonding and Proton Transfer to [Cp*Fe(dppe)H]

Belkova

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et al. 2005

Chemistry A European J

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The present contribution reports experimental and computational investigations of the interaction between [Cp*Fe(dppe)H] and different proton donors (HA). The focus is on the structure of the proton transfer intermediates and on the potential energy surface of the proton transfer leading to the dihydrogen complex [Cp*Fe(dppe)(H2)]+. With p-nitrophenol (PNP) a UV/Visible study provides evidence of the formation of the ion-pair stabilized by a hydrogen bond between the nonclassical cation [Cp*Fe(dppe)(H2)]+ and the homoconjugated anion ([AHA]-). With trifluoroacetic acid (TFA), the hydrogen-bonded ion pair containing the simple conjugate base (A-) in equilibrium with the free ions is observed by IR spectroscopy when using a deficit of the proton donor. An excess leads to the formation of the homoconjugated anion. The interaction with hexafluoroisopropanol (HFIP) was investigated quantitatively by IR spectroscopy and by 1H and 31P NMR spectroscopy at low temperatures (200-260 K) and by stopped-flow kinetics at about room temperature (288-308 K). The hydrogen bond formation to give [Cp*Fe(dppe)H]HA is characterized by DeltaH degrees =-6.5+/-0.4 kcal mol(-1) and DeltaS degrees = -18.6+/-1.7 cal mol(-1) K(-1). The activation barrier for the proton transfer step, which occurs only upon intervention of a second HFIP molecule, is DeltaH(not equal) = 2.6+/-0.3 kcal mol(-1) and DeltaS(not equal) = -44.5+/-1.1 cal mol(-1) K(-1). The computational investigation (at the DFT/B3 LYP level with inclusion of solvent effects by the polarizable continuum model) reproduces all the qualitative findings, provided the correct number of proton donor molecules are used in the model. The proton transfer process is, however, computed to be less exothermic than observed in the experiment.

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Section: Full Papermentioning

confidence: 99%

Experimental and Computational Studies of Hydrogen Bonding and Proton Transfer to [Cp*Fe(dppe)H]

Belkova

Collange

Dub

et al. 2005

Chemistry A European J

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133

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“…In a separate study done by Lledós on the same system, the hybrid quantum mechanics/molecular mechanics (QM/MM) method IMOMM was applied to each reaction step to quantify and separate the effect of methyl substituents in both C 5 Me 5 and PMe 3 ligands into steric and electronic contributions . This study showed that substitution at the 3 and 4 positions of thiophene have a more significant steric effect on the C−S bond cleavage barrier compared to substitution at the 2 and 5 positions, contrary to previously reported experimental studies which demonstrated that the insertion reaction with 2-methyl thiophene gave one product, whereas 3-methyl thiophene gave two insertion products in a 1:1 ratio.…”

Section: Introductionmentioning

confidence: 79%

Oxidative Addition of the C−S Bond of Thiophene to the (C₅Me₅)Rh(PMe₃) Fragment: A Theoretical Study Revisited

Ateşin

Jones

2008

Organometallics

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Density functional theory (DFT) calculations on the C−S bond activation reaction of thiophene with the [(C5Me5)Rh(PMe3)] fragment have been reinvestigated, giving two new isomeric C−S bond activation transition states, in which the coordinated thiophene molecule tilts toward either the C5Me5 ligand or the PMe3 ligand. Through intrinsic reaction coordinate (IRC) calculations, these transition states were found to connect the oxidative addition product with two isomeric η2-C,S coordinated intermediates. These latter intermediates in turn connected to two isomeric η1-S and η2-C,C coordinated species. The energetics and mechanistic details are described.

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“…Indeed, QM/MM methodology has even been employed specifically as an analytical method, rather than as a practical approach, in order to quantify the relative contribution of steric and electronic effects. [159][160][161] In this application 146 the authors were able to determine which of the contributing terms to the energy was most affecting the enantioselectivity by a comparison of the relative contribution to the R and S TSs.…”

Section: Qm/mm Methods In Catalysis -The Role Of Ligandsmentioning

confidence: 99%

Applications of QM/MM in inorganic chemistry

Tell¹

2010

Spectroscopic Properties of Inorganic and Organometallic Compounds

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Quantum mechanical/molecular mechanical (QM/MM) methods play an increasingly important role in the study of inorganic systems. From the early application of QM/MM methods, to organometallic catalysts, to the present day use of QM/MM methods in studying bioinorganic systems, the development and uptake of the methodology has been startling. In this review, an outline of the theories for the two major QM/MM schemes (additive and subtractive) is provided. Two case studies, within inorganic chemistry, highlight the strengths of the different approaches. The use of the subtractive QM/MM scheme to decompose a system in terms of specific contributions of chemical moieties and energetic factors provides insight into the nature of how a reaction occurs. While the use of an additive QM/MM methodology in computational spectroscopy has shown the important role of the environment in influencing these parameters. Through the careful callibration of the computational and experimental results, new details about the mechanistic and structural details of inorganic systems are revealed.

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Computational QM/MM study on the structure and energetics of species involved in the activation of the C–H and C–S bonds of thiophene by Cp*RhPMe₃

Cited by 23 publications

References 58 publications

Experimental and Computational Studies of Hydrogen Bonding and Proton Transfer to [Cp*Fe(dppe)H]

Experimental and Computational Studies of Hydrogen Bonding and Proton Transfer to [Cp*Fe(dppe)H]

Oxidative Addition of the C−S Bond of Thiophene to the (C₅Me₅)Rh(PMe₃) Fragment: A Theoretical Study Revisited

Applications of QM/MM in inorganic chemistry

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Computational QM/MM study on the structure and energetics of species involved in the activation of the C–H and C–S bonds of thiophene by Cp*RhPMe3

Cited by 23 publications

References 58 publications

Experimental and Computational Studies of Hydrogen Bonding and Proton Transfer to [Cp*Fe(dppe)H]

Experimental and Computational Studies of Hydrogen Bonding and Proton Transfer to [Cp*Fe(dppe)H]

Oxidative Addition of the C−S Bond of Thiophene to the (C5Me5)Rh(PMe3) Fragment: A Theoretical Study Revisited

Applications of QM/MM in inorganic chemistry

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Computational QM/MM study on the structure and energetics of species involved in the activation of the C–H and C–S bonds of thiophene by Cp*RhPMe₃

Oxidative Addition of the C−S Bond of Thiophene to the (C₅Me₅)Rh(PMe₃) Fragment: A Theoretical Study Revisited