Determination of Ruthenium−Phosphorus Bond Dissociation Energies by ES-FTICR Mass Spectrometry

Han

et al. 2013

J. Phys. Org. Chem.

The knowledge of accurate bond strengths is a fundamental basis for a proper analysis of chemical reaction mechanisms. Quantum chemical calculations at different levels of theory have been used to investigate heterolytic Fe–O and Fe–S bond energies of para‐substituted phenoxydicarbonyl(η5‐cyclopentadienyl) iron [p‐G‐C6H4O(η5‐C5H5)Fe(CO)2, abbreviated as p‐G‐C6H4OFp (1), where G = NO2, CN, COMe, CO2Me, CF3, Br, Cl, F, H, Me, MeO, and NMe2] and para‐substituted benzenethiolatodicarbonyl(η5‐cyclopentadienyl) iron [p‐G‐C6H4S(η5‐C5H5)Fe(CO)2, abbreviated as p‐G‐C6H4SFp (2)] complexes. The results show that BP86 and TPSSTPSS can provide the best price/performance ratio and more accurate predictions in the study of ΔHhet(Fe–O)'s and ΔHhet(Fe–S)'s. The excellent linear free‐energy relations [r = 0.99 (g, 1a), 1.00 (g, 2b)] among the ΔΔHhet (Fe–O)'s and Δpka's of O–H bonds of p‐G‐C6H4OH or ΔΔHhet(Fe‐S)'s and Δpka's of S–H bonds of p‐G‐C6H4SH imply that the governing structural factors for these bond scissions are similar. And the linear correlations [r = −0.99 (g, 1g), −0.98 (g, 2h)] among the ΔΔHhet (Fe‐O)'s or ΔΔHhet(Fe‐S)'s and the substituent σp− constants show that these correlations are in accordance with Hammett linear free‐energy relationships. The polar effects of these substituents and the basis set effects influence the accuracy of ΔHhet(Fe–O)'s or ΔHhet(Fe–S)'s. ΔΔHhet(Fe–O)'s(g) (1) and ΔΔHhet(Fe–S)'s(g)(2) follow the Capto‐dative principle. The substituent effects on the Fe–O bonds are much stronger than those on the less polar Fe–S bonds. Insight from this work may help the design of more effective catalytic processes. Copyright © 2013 John Wiley & Sons, Ltd.

Section: Introductionmentioning

confidence: 99%

Hartree-Fock and density functional theory study of remote substituent effects on gas-phase heterolytic Fe-O and Fe-S bond energies of p -G-C₆ H₄ OFe(CO)₂ (η ⁵ -C₅ H₅ ) and p -G-C₆ H₄ SFe(CO)₂ (η ⁵ -C₅ H₅ )

Han

et al. 2013

J. Phys. Org. Chem.

“…The breaking and formation of metal–ligand bonds are fundamental to organometallic chemistry, and knowledge of the strengths of such bonds is necessary for understanding the thermodynamics underlying many important stoichiometric and catalytic organometallic reactions . Despite the development of a range of techniques for probing metal–ligand bond energy information, both in solution and in the gas phase, the amassed library of organometallic bond energies remains extremely limited . In contrast to the situation for lighter systems, where bond strengths are qualitatively well known, experimental bond strengths in transition metal complexes are much more uncertain .…”

Section: Introductionmentioning

confidence: 99%

“…Thus, it is of considerable importance to have quantitative information about the gas‐phase heterolytic bond dissociation energies of Fe―C bonds. The definite and immediate need of the data bank has spurred us to investigate the heterolytic Fp―C bond energies …”

Section: Introductionmentioning

confidence: 99%

“…[1] Despite the development of a range of techniques for probing metal-ligand bond energy information, both in solution and in the gas phase, the amassed library of organometallic bond energies remains extremely limited. [2][3][4] In contrast to the situation for lighter systems, where bond strengths are qualitatively well known, experimental bond strengths in transition metal complexes are much more uncertain. [5] However, modern theoretical methods have the potential to provide accurate bond enthalpy data.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hartree–Fock and density functional theory study of remote substituent effects on heterolytic Fe―C bond energies of p‐G‐C₆H₄CH₂Fe(CO)₂(η⁵‐C₅H₅) and p‐G‐C₆H₄(H)(CN)CFe(CO)₂(η⁵‐C₅H₅)

J of Physical Organic Chem

2011

Knowledge of the strength of the metal–ligand bond breaking and formation is fundamental for an understanding of the thermodynamics underlying many important stoichiometric and catalytic organometallic reactions. Quantum chemical calculations at different levels of theory have been used to investigate heterolytic Fe―C bond energies of para‐substituted benzyldicarbonyl(η5‐cyclopentadienyl)iron, p‐G‐C6H4CH2Fp [1, G = NO2, CN, COMe, CO2Me, CF3, Br, Cl, F, H, Me, MeO, NMe2; Fp = (η5‐C5H5)(CO)2Fe], and para‐substituted α‐cyanobenzyldicarbonyl(η5‐cyclopentadienyl)iron, p‐G‐PANFp [2, PAN = C6H4CH(CN)]. The results show that BP86 and TPSSTPSS can provide the best price/performance ratio and more accurate predictions in the study of ΔHhet(Fe―C)'s. The good linear correlations [r = 0.98 (g, 1a), 0.99 (g, 2b)] between the substituent effects of heterolytic Fe―C bond energies [ΔΔHhet(Fe―C)'s] of series 1 and 2 and the differences of acidic dissociation constants (ΔpKa) of C―H bonds of p‐G‐C6H4CH3 and p‐G‐C6H4CH2CN imply that the governing structural factors for these bond scissions are similar. And the excellent linear correlations [r = −1.00 (g, 1c), −0.99 (g, 2d)] between ΔΔHhet(Fe―C)'s and the substituent σp− constants show that these correlations are in accordance with Hammett linear free energy relationships. The polar effects of these substituents and the basis set effects influence the accuracy of ΔHhet(Fe―C)'s. ΔΔHhet(Fe―C)'s(1, 2) follow the Capto‐dative Principle. The detailed knowledge of the factors that determine the Fp―C bond strengths would greatly aid in understanding reactivity patterns in many processes. Copyright © 2011 John Wiley & Sons, Ltd.

“…Thus, it is of considerable importance to have quantitative information about the gas‐phase Δ H het s of Fe–O and Fe–S bonds. The definite and immediate need of the data bank has spurred us to investigate the Δ H het s …”

Section: Introductionmentioning

confidence: 99%

Density functional theory study of substituent effects on gas‐phase heterolytic Fe–O and Fe–S bond energies of m‐G‐C₆H₄OFe(CO)₂(η⁵‐C₅H₅) and m‐G‐C₆H₄SFe(CO)₂(η⁵‐C₅H₅)

J of Physical Organic Chem

Wang

et al. 2016

The knowledge of accurate bond strengths is a fundamental basis for a proper analysis of chemical reaction mechanisms. Quantum chemical calculations at different levels of theory have been used to investigate heterolytic Fe–O and Fe–S bond energies of (meta‐substituted phenoxy)dicarbonyl(η5‐cyclopentadienyl) iron [m‐G‐C6H4OFp (1)] and (meta‐substituted benzenethiolato)dicarbonyl(η5‐cyclopentadienyl) iron [m‐G‐C6H4SFp (2)] complexes. In this study, Fp is (η5‐C5H5)Fe(CO)2, and G is NO2, CN, COMe, CO2Me, CF3, Br, Cl, F, H, Me, MeO, and NMe2. The results show that Tao–Perdew–Staroverov–Scuseria and Becke's power‐series ansatz from 1997 with dispersion corrections functionals can provide the best price/performance ratio and accurate predictions of ΔHhet(Fe–O)'s and ΔHhet(Fe–S)'s. The excellent linear free energy relations [r = 1.00 (g, 1e), 1.00 (g, 2b)] among the ΔΔHhet (Fe–O)'s and δΔG0 of OH bonds of m‐G‐C6H4OH or ΔΔHhet(Fe–S)'s and ΔpKa's of SH bonds of m‐G‐C6H4SH imply that the governing structural factors for these bond scissions are similar. And, the linear correlations [r = −0.97 (g, 1 g), −0.97 (g, 2 h)] among the ΔΔHhet (Fe–O)'s or ΔΔHhet(Fe–S)'s and the substituent σm constants show that these correlations are in accordance with Hammett linear free energy relationships. The inductive effects of these substituents and the basis set effects influence the accuracy of ΔHhet(Fe–O)'s or ΔHhet(Fe–S)'s. The ΔΔHhet(Fe–O)'s(g) (1) and ΔΔHhet(Fe–S)'s(g)(2) follow the capto‐dative Principle. The substituent effects on the Fe–O bonds are much stronger than those on the less polar Fe–S bonds. Insight from this work may help the design of more effective catalytic processes. Copyright © 2016 John Wiley & Sons, Ltd.