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Université de Fribourg

The angular overlap model extended for two-open-shell f and d electrons

Ramanantoanina, Harry ; Urland, Werner ; Cimpoesu, Fanica ; Daul, Claude

In: Physical Chemistry Chemical Physics, 2014, vol. 16, no. 24, p. 12282–12290

We discuss the applicability of the Angular Overlap Model (AOM) to evaluate the electronic structure of lanthanide compounds, which are currently the subject of incredible interest in the field of luminescent materials. The functioning of phosphors is well established by the f–d transitions, which requires the investigation of both the ground 4fn and excited 4fn−15d1 electron configurations...

Université de Fribourg

Benzo[1,2-b:4,5-b′]difuran-based sensitizers for dye-sensitized solar cells

Li, Hui ; Yi, Chenyi ; Moussi, Sofiane ; Liu, Shi-Xia ; Daul, Claude ; Grätzel, Michael ; Decurtins, Silvio

In: RSC Advances, 2013, vol. 3, no. 43, p. 19798–19801

Two BDF-based organic sensitizers, as first examples for their use in dye-sensitized solar cells, are prepared and characterized. They yield promising power conversion efficiencies of up to 5.5% and high open circuit voltages up to 0.82 V. This work demonstrates that the BDF chromophore acts as an effective donor in organic sensitizers.

Université de Fribourg

Calculation of the 4f¹ → 4f⁰5d¹ transitions in Ce³⁺-doped systems by Ligand Field Density Functional Theory

Ramanantoanina, Harry ; Urland, Werner ; García-Fuente, Amador ; Cimpoesu, Fanica ; Daul, Claude

In: Chemical Physics Letters, 2013, vol. 588, p. 260–266

We present a recipe for the calculation of the optical properties of Ce³⁺-doped systems. The model implies the use of ligand field phenomenology in conjunction with Density Functional Theory (DFT). The particular procedures enable the reliable prediction of the 4f¹ → 4f⁰5d¹ transitions in Cs₂NaYCl₆:Ce³⁺. The analysis of the doping of Ce³⁺ into the host is accomplished by band...

Université de Fribourg

The choice of the exchange-correlation functional for the determination of the jahn–teller parameters by the density functional theory

Andjelković, Ljubica ; Gruden-Pavlović, Maja ; Daul, Claude ; Zlatar, Matija

In: International Journal of Quantum Chemistry, 2012, p. -

The Jahn–Teller (JT) parameters for small, aromatic, organic radicals, CnHn (n = 4–7), bis(cyclopentadienyl)cobalt(II) (cobaltocene), a sodium cluster (Na3), a silver cluster (Ag3), the hexaflurocuprate(II) ion ([CuF6]4−), and tris(acetylacetonato)manganese(III) ([Mn(acac)3]) have been evaluated by the means of the multideterminantal density functional theory using the most common...

Université de Fribourg

Computational analysis of tris(1,2-ethanediamine) cobalt(III) complex ion : calculation of the ⁵⁹Co shielding tensor using LF-DFT

Senn, Florian ; Zlatar, Matija ; Gruden-Pavlovic, Maja ; Daul, Claude

In: Monatshefte für Chemie - Chemical Monthly : an International Journal of Chemistry, 2011, vol. 142, no. 6, p. 593-597

The ligand-field density functional theory (LF-DFT) approach is employed for calculations of the ⁵⁹Co nuclear magnetic resonance (NMR) shielding tensor of all four diastereoisomers (λλλ, λλδ, λδδ, and δδδ) of tris(1,2-ethanediamine) cobalt(III) complex ion, [Co(en)₃]³⁺. The obtained values split into two groups according to the point group of the diastereoisomers. The...

Université de Fribourg

Core electron excitations in U⁴⁺: modelling of the nd¹⁰5f² → nd⁹5f³ transitions with n = 3, 4 and 5 by ligand field tools and density functional theory

Ramanantoanina, Harry ; Kuri, Goutam ; Daul, Claude ; Bertsch, Johannes

In: Physical Chemistry Chemical Physics, 2016, vol. 18, no. 28, p. 19020–19031

Ligand field density functional theory (LFDFT) calculations have been used to model the uranium M4,5, N4,5 and O4,5-edge X-ray absorption near edge structure (XANES) in UO₂, characterized by the promotion of one electron from the core and the semi-core 3d, 4d and 5d orbitals of U⁴⁺ to the valence 5f. The model describes the procedure to resolve...

Université de Fribourg

DFT investigation of methane metathesis with L2AnCH3 actinide complexes catalysts (L = Cl, Cp, Cp*; An = Ac, Th, Pa, U, Np, Pu)

Talbi-Ingrachen, Fazia ; Talbi, Fatiha ; Kias, Farida ; Elkechai, Aziz ; Boucekkine, Abdou ; Daul, Claude

In: Computational and Theoretical Chemistry, 2018, vol. 1138, p. 123–134

In order to understand the catalytic activity of the actinide complexes L2AnCH3 (An = Ac, Th, Pa, U, Np and Pu; L = Cl, Cp and Cp∗) towards the activation of the CH bond of methane, relativistic ZORA/DFT investigations have been carried out. The results obtained from Linear Transit (LT) and Intrinsic Reaction Coordinate (IRC) calculations show that the mechanism involved in these...

Université de Fribourg

DFT study of mixed-valent Mn(II/III) hexacyanide clusters

Daul, Claude ; Rauzy, Cédrick ; Decurtins, Silvio ; Franz, Patrick ; Hauser, Andreas

In: International Journal of Quantum Chemistry, 2005, vol. 101, no. 6, p. 753-760

The cubic Prussian blue analogue Mn³[Mn(CN)₆]₂·15H₂O, which has the advantage of being transparent and magnetic (TN = 35 K) at the same time, has been investigated by density functional theory (DFT) calculations. The three-dimensional structure is built of MnII ions linked to MnIII ions by μ-bridging cyanides, to form a crystal structure,...