Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities Christophe Copeŕet,*,† Aleix Comas-Vives,† Matthew P. Conley,† Deven P. Estes,† Alexey Fedorov,† Victor Mougel,† Haruki Nagae,†,‡ Francisco Nuñ́ez-Zarur,† and Pavel A. Zhizhko†,§ †Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1−5, CH-8093 Zürich, Switzerland ‡Department of Chemistry, Graduate School of Engineering Science, Osaka University, CREST, Toyonaka, Osaka 560-8531, Japan A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str. 28, 119991 Moscow, Russia

Surface Organometallic and Coordination Chemistry toward Single-Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities

Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments / Albert Rimola;Dominique Costa;Mariona Sodupe;Jean-François Lambert;Piero Ugliengo. In: CHEMICAL REVIEWS. ISSN 0009-2665. STAMPA. 113:6(2013), pp. 4216-4313. Original Citation: Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments

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Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments

Including Projector Augmented Wave Method: A Chemist’s Point of View Christian Bonhomme,*,† Christel Gervais,*,† Florence Babonneau,† Cristina Coelho,‡ Fred́eŕique Pourpoint,† Thierry Azaïs,† Sharon E. Ashbrook,* John M. Griffin, Jonathan R. Yates,* Francesco Mauri, and Chris J. Pickard †Laboratoire de Chimie de la Matier̀e Condenseé de Paris, Universite ́ Pierre et Marie Curie, Paris 06, CNRS UMR 7574, Colleg̀e de France, 75005 Paris, France ‡IMPC, Institut des Mateŕiaux de Paris Centre, FR2482, UPMC Universite ́ Pierre et Marie Curie Paris 06, Colleg̀e de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France School of Chemistry and EaStCHEM, University of St. Andrews, North Haugh, St. Andrews KY16 9ST, United Kingdom Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom Laboratoire de Mineŕalogie Crystallographie, UMR CNRS 7590, Universite ́ Pierre et Marie Curie, UPMC, 75015 Paris, France Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom

First-principles calculation of NMR parameters using the gauge including projector augmented wave method:a chemist's point of view

The PAW/GIPAW approach for computing NMR parameters: a new dimension added to NMR study of solids.

Understanding the acid-base behavior of silica surfaces is critical for many nanoscience and bionano interface applications. Silanol groups (SiOH) on silica surfaces exhibit two acidity constants-one as acidic as vinegar-but their structural basis remains controversial. The atomic details of the more acidic silanol site govern not just the overall surface charge density at near neutral solution pH but also how ions and biomolecules interact with and bind to silica immersed in water. Using ab initio molecular dynamics simulations and multiple representative crystalline silica surfaces, we determine the deprotonation free energies of silanol groups with different structural motifs. We show that previously proposed motifs related to chemical connectivity or intersilanol hydrogen bonds do not yield high acidity. Instead, a plausible candiate for pK(a) = 4.5 silanol groups may be found in locally strained or defected regions with sparse silanol coverage. In the process, irreversible ring-opening reactions of strained silica trimer rings in contact with liquid water are observed.

Elucidating the bimodal acid-base behavior of the water-silica interface from first principles.

A new complete, representative model for the hydroxylated surface of amorphous silica is presented and characterized by means of periodic DFT calculations. This model accounts for the experimentally encountered ring size distribution, Si-O-Si and O-Si-O angles, silanols density, and distribution (isolated, associated, geminals). Properties such as NMR shifts, dehydrogenation energies, OH vibrational frequencies, and the interaction with water are investigated. The results are compared with former experimental and theoretical results. This new representative model for this complex surface would probably help the investigation of its reactivity toward amino acids or other organic molecules, opening new perspectives in the understanding of the chemistry of amorphous materials.

Ab Initio Study of the Hydroxylated Surface of Amorphous Silica: A Representative Model

47,49Ti solid-state NMR spectra are reported from TiO2 nanoparticles. Particles heated below 700 °C are predominantly anatase. The corresponding 47,49Ti NMR spectra can be simulated by using the NM...

Christelle Gervais

Papers

Ab Initio Study of the Hydroxylated Surface of Amorphous Silica: A Representative Model

Solid-state 47,49Ti NMR determination of the phase distribution of titania nanoparticles

Calcium phosphates: First-principles calculations vs. solid-state NMR experiments