Blue-Shifting Hydrogen Bonds

Hobza, Pavel; Havlas, Zdeněk

doi:10.1021/cr990050q

Cited by 1,715 publications

(1,314 citation statements)

References 54 publications

Supporting

Mentioning

1,222

Contrasting

Unclassified

Order By: Relevance

“…2A). This difference originates from the additional Ni-S bonding interactions in (NiDACO) 2 Ni considered below.…”

Section: Resultsmentioning

confidence: 99%

“…The complexes Ni II 2 Ni] were synthesized as described in Reference 23. Dry acetonitrile (%H 2 O ≪0.01%) was obtained from Acros.…”

Section: Methodsmentioning

confidence: 99%

“…The sample was then mounted across the window of an aluminum plate. Fresh solutions of Ni(DACO) and [Ni(DACO) 2 Ni] were prepared before the experiments ~ 10 mM in concentration. The solutions were loaded via a syringe into a Pt-plated Al block sample holder sealed in front using a 6.3 μm polypropylene window and maintained at a constant temperature of 4°C during data collection using a controlled flow of N 2 gas pre-cooled by liq.…”

Section: Methodsmentioning

confidence: 99%

“…(1) where α is the ligand coefficient in the half-occupied or unoccupied orbital. The intensity (I) of the L 1s →M 3d transition is; (2) where I(L 1s →L np ) is the intensity of a purely ligand based 1s→np transition, which depends primarily on the Z eff of the ligand. 17 The pre-edge intensity thus provides a direct estimate of ligand-metal bond covalency (α 2 ).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

S K-Edge XAS and DFT Calculations on Square-Planar Ni^II−Thiolate Complexes: Effects of Active and Passive H-Bonding

et al. 2007

View full text Add to dashboard Cite

S K-edge XAS for a low-spin Ni II -thiolate complex shows a 0.2 eV shift to higher pre-edge energy but no change in Ni-S bond covalency upon H-bonding. This is different from the H-bonding effect we observed in high spin Fe III -thiolate complexes where there is a significant decrease in Fe-S bond covalency but no change in energy due to H-bonding (Dey, A.; Okamura, T.-A.; Ueyama, N.; Hedman, B.; Hodgson, K. O.; Solomon, E. I. J. Am. Chem. Soc.; 127, 12046-12053.). These differences were analyzed using DFT calculations and the results indicate that two different types of H-bonding interactions are possible in metal-thiolate systems. In the high-spin Fe III -thiolate case, the H-bonding involves a thiolate donor orbital which is also involved in bonding with the metal (active), while in the low-spin Ni II -thiolate the orbital involved in H-bonding is non-bonding with respect to the M-S bonding (passive). The contributions of active and passive H-bonds to the reduction potential and Lewis acid properties of a metal center are evaluated.

show abstract

“…2A). This difference originates from the additional Ni-S bonding interactions in (NiDACO) 2 Ni considered below.…”

Section: Resultsmentioning

confidence: 99%

“…The complexes Ni II 2 Ni] were synthesized as described in Reference 23. Dry acetonitrile (%H 2 O ≪0.01%) was obtained from Acros.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

S K-Edge XAS and DFT Calculations on Square-Planar Ni^II−Thiolate Complexes: Effects of Active and Passive H-Bonding

et al. 2007

View full text Add to dashboard Cite

show abstract

“…1,2 Many active sites have highly conserved H-bonds which appear to be key to the site function as their mutation greatly reduces reactivity. 3 The functional role of these H-bonds has been extensively investigated using different experimental and computational techniques.…”

Section: Introductionmentioning

confidence: 99%

Sulfur K-Edge XAS and DFT Calculations on P450 Model Complexes: Effects of Hydrogen Bonding on Electronic Structure and Redox Potentials

et al. 2005

View full text Add to dashboard Cite

Hydrogen bonding is generally thought to play an important role in tuning the electronic structure and reactivity of metal-sulfur sites in proteins. To develop a quantitative understanding of this effect, S K-edge X-ray absorption spectroscopy (XAS) has been employed to directly probe ligand-metal bond covalency, where it has been found that protein active sites are significantly less covalent than their related model complexes. Sulfur K-edge XAS data are reported here on a series of P450 model complexes with increasing H-bonding to the ligated thiolate from its substituent. The XAS spectroscopic results show a dramatic decrease in pre-edge intensity. DFT calculations reproduce these effects and show that the observed changes are in fact solely due to H-bonding and not from the inductive effect of the substituent on the thiolate. These calculations also indicate that the Hbonding interaction in these systems is mainly dipolar in nature. The −2.5 kcal/mole energy of the H-bonding interaction was small relative to the large change in ligand-metal bond covalency (30%) observed in the data. A bond decomposition analysis of the total energy is developed to correlate the pre-edge intensity change to the change in Fe-S bonding interaction on H-bonding. This effect is greater for the reduced than the oxidized state, leading to a 330 mV increase in the redox potential. A simple model shows that E° should vary approximately linearly with the covalency of the Fe-S bond in the oxidized state, which can be determined directly from S K-edge XAS.

show abstract

Molecular Complexes: Perturbations of Vibrational Spectra

Ford

1998

Encyclopedia of Computational Chemistry

View full text Add to dashboard Cite

The structures, interaction energies, and vibrational spectra of a series of molecular complexes containing boron trifluoride as the electron acceptor and a variety of oxygen, nitrogen, sulfur, and halogen bases as the electron donors have been computed. The effects of the molecular interactions on the vibrational properties of the boron trifluoride species have been studied, and the degree of perturbation has been correlated with some of the properties of the bases.

show abstract

Blue-Shifting Hydrogen Bonds

Cited by 1,715 publications

References 54 publications

S K-Edge XAS and DFT Calculations on Square-Planar Ni^II−Thiolate Complexes: Effects of Active and Passive H-Bonding

S K-Edge XAS and DFT Calculations on Square-Planar Ni^II−Thiolate Complexes: Effects of Active and Passive H-Bonding

Sulfur K-Edge XAS and DFT Calculations on P450 Model Complexes: Effects of Hydrogen Bonding on Electronic Structure and Redox Potentials

Molecular Complexes: Perturbations of Vibrational Spectra

Contact Info

Product

Resources

About

Blue-Shifting Hydrogen Bonds

Cited by 1,715 publications

References 54 publications

S K-Edge XAS and DFT Calculations on Square-Planar NiII−Thiolate Complexes: Effects of Active and Passive H-Bonding

S K-Edge XAS and DFT Calculations on Square-Planar NiII−Thiolate Complexes: Effects of Active and Passive H-Bonding

Sulfur K-Edge XAS and DFT Calculations on P450 Model Complexes: Effects of Hydrogen Bonding on Electronic Structure and Redox Potentials

Molecular Complexes: Perturbations of Vibrational Spectra

Contact Info

Product

Resources

About

S K-Edge XAS and DFT Calculations on Square-Planar Ni^II−Thiolate Complexes: Effects of Active and Passive H-Bonding

S K-Edge XAS and DFT Calculations on Square-Planar Ni^II−Thiolate Complexes: Effects of Active and Passive H-Bonding