Contributions of dispersion forces to R-3-methylcyclohexanone physisorption on low and high Miller index Cu surfaces

Wei, Daniel; Mhatre, Bharat S.; Gellman, Andrew J.; Sholl, David S.

doi:10.1016/j.susc.2014.03.022

Cited by 7 publications

(10 citation statements)

References 58 publications

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“…The TPD spectra from Cu(6 5 3) R and Cu(6 4 3) R surfaces exhibit R-3MCHO desorption features at ~250 K attributable to desorption from flat (1 1 1) terraces; features at = T p 345 K attributable to desorption from the close-packed step edges; and a new feature at = T p 385 K that is attributed to desorption of molecules bound to the kink sites. In addition to the clear implications of the TPD spectra, adsorption energetics calculated using DFT are consistent with this assignment [23].…”

Section: R-3mcho Desorption From Surfaces Vicinal To Cu(1 1 1)supporting

confidence: 67%

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl)^R&S surfaces

Gellman

Huang

Koritnik

et al. 2016

J. Phys.: Condens. Matter

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The desorption kinetics of a chiral compound, R-3-methylcyclohexanone (R-3MCHO), have been measured on both enantiomers of seven chiral Cu(hkl) surfaces and on nine achiral Cu single crystal surfaces with surface structures that collectively span the various regions of the stereographic triangle. The naturally chiral surfaces have terrace-step-kink structures formed by all six possible combinations of the three low Miller index microfacets. The chirality of the kink sites is defined by the rotational orientation of the (1 1 1), (1 0 0) and (1 1 0) microfacets forming the kink. R-3MCHO adsorbs reversibly on these Cu surfaces and temperature programmed desorption has been used to measure its desorption energetics from the chiral kink sites. The desorption energies from the R- and S-kink sites are enantiospecific, [Formula: see text], on the chiral surfaces. The magnitude of the enantiospecificity is [Formula: see text] ≈ 1 kJ mol on all seven chiral surfaces. However, the values of [Formula: see text] are sensitive to elements of the surface structure other than just their sense of chirality as defined by the rotational orientation of the low Miller index microfacets forming the kinks; [Formula: see text] changes sign within the set of surfaces of a given chirality.

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Section: R-3mcho Desorption From Surfaces Vicinal To Cu(1 1 1)supporting

confidence: 67%

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl)^R&S surfaces

Gellman

Huang

Koritnik

et al. 2016

J. Phys.: Condens. Matter

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“…We opted for this functional as van der Waals interactions were found to be important for the correct description of weakly bound molecules on surfaces. [58][59][60] The Projector Augmented Wave method [61,62] was employed with an energy cutoff of 400 eV. Structural relaxations were stopped when all forces were smaller than 10 meV/ Å with wavefunctions converged to energy changes between successive steps smaller than 10 −5 eV.…”

Section: Computational Detailsmentioning

confidence: 99%

Chiral selectivity of amino acid adsorption on chiral surfaces—The case of alanine on Pt

Franke

Kosov

2015

The Journal of Chemical Physics

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We study the binding pattern of the amino acid alanine on the naturally chiral Pt surfaces Pt(531), Pt(321), and Pt(643). These surfaces are all vicinal to the {111} direction but have different local environments of their kink sites and are thus a model for realistic roughened Pt surfaces. Alanine has only a single methyl group attached to its chiral center, which makes the number of possible binding conformations computationally tractable. Additionally, only the amine and carboxyl group are expected to interact strongly with the Pt substrate. On Pt(531), we study the molecule in its pristine as well as its deprotonated form and find that the deprotonated one is more stable by 0.47 eV. Therefore, we study the molecule in its deprotonated form on Pt(321) and Pt(643). As expected, the oxygen and nitrogen atoms of the deprotonated molecule provide a local binding "tripod" and the most stable adsorption configurations optimize the interaction of this "tripod" with undercoordinated surface atoms. However, the interaction of the methyl group plays an important role: it induces significant chiral selectivity of about 60 meV on all surfaces. Hereby, the L-enantiomer adsorbs preferentially to the Pt(321)(S) and Pt(643)(S) surfaces, while the D-enantiomer is more stable on Pt(531)(S). The binding energies increase with increasing surface density of kink sites, i.e., they are largest for Pt(531)(S) and smallest for Pt(643)(S).

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“…The inclusion of the van der Waals forces is crucial for the adsorption of a weakly bound molecule since they dominate the binding energy. [53][54][55] We opted for this special version of the vdW-DF functional since we wanted to keep the PBE class of functionals while also aiming at an optimal accuracy with the vdW nonlocal correlation. The Projector Augmented Wave method [56,57] was employed with valence wave functions expanded up to an energy cutoff of 400 eV.…”

Section: Computational Detailsmentioning

confidence: 99%

Adsorption and ring-opening of lactide on the chiral metal surface Pt(321)S studied by density functional theory

Franke

Kosov

2015

The Journal of Chemical Physics

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We study the adsorption and ring-opening of lactide on the naturally chiral metal surface Pt(321)(S). Lactide is a precursor for polylactic acid ring-opening polymerization, and Pt is a well known catalyst surface. We study, here, the energetics of the ring-opening of lactide on a surface that has a high density of kink atoms. These sites are expected to be present on a realistic Pt surface and show enhanced catalytic activity. The use of a naturally chiral surface also enables us to study potential chiral selectivity effects of the reaction at the same time. Using density functional theory with a functional that includes the van der Waals forces in a first-principles manner, we find modest adsorption energies of around 1.4 eV for the pristine molecule and different ring-opened states. The energy barrier to be overcome in the ring-opening reaction is found to be very small at 0.32 eV and 0.30 eV for LL- and its chiral partner DD-lactide, respectively. These energies are much smaller than the activation energy for a dehydrogenation reaction of 0.78 eV. Our results thus indicate that (a) ring-opening reactions of lactide on Pt(321) can be expected already at very low temperatures, and Pt might be a very effective catalyst for this reaction; (b) the ring-opening reaction rate shows noticeable enantioselectivity.

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Contributions of dispersion forces to R-3-methylcyclohexanone physisorption on low and high Miller index Cu surfaces

Cited by 7 publications

References 58 publications

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl)^R&S surfaces

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl)^R&S surfaces

Chiral selectivity of amino acid adsorption on chiral surfaces—The case of alanine on Pt

Adsorption and ring-opening of lactide on the chiral metal surface Pt(321)S studied by density functional theory

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Contributions of dispersion forces to R-3-methylcyclohexanone physisorption on low and high Miller index Cu surfaces

Cited by 7 publications

References 58 publications

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl) R&S surfaces

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl) R&S surfaces

Chiral selectivity of amino acid adsorption on chiral surfaces—The case of alanine on Pt

Adsorption and ring-opening of lactide on the chiral metal surface Pt(321)S studied by density functional theory

Contact Info

Product

Resources

About

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl)^R&S surfaces

Structure-sensitive enantiospecific adsorption on naturally chiral Cu(hkl)^R&S surfaces