References of "Kryachko, Eugène"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detail20-Nanogold Au20(Td) and Low-Energy Hollow Cages: Void Reactivity
Kryachko, Eugène ULg; Remacle, Françoise ULg; Hoggan, P. E. et al

in Advances in the Theory of Quantum Systems in Chemistry and Physics (2012)

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailImplementation of simple logic gates on gold-ammonia bonding patterns in different charge states
Kryachko, Eugène ULg; Remacle, Françoise ULg

in Molecular Physics (2008), 106(2-4), 521-530

An approach is proposed for encoding the gold-ammonia bonding patterns on the conformational manifold of the Au-n(Z)-(NH3)(m), Z=0, +/- 1, clusters in order to implement simple unary and binary logic gate ... [more ▼]

An approach is proposed for encoding the gold-ammonia bonding patterns on the conformational manifold of the Au-n(Z)-(NH3)(m), Z=0, +/- 1, clusters in order to implement simple unary and binary logic gate operations. The gold-ammonia bonding patterns are governed by two different basic ingredients: the anchoring Au-N bond and the nonconventional N-H center dot center dot center dot Au hydrogen bond, and exhibit distinct characteristics as the charge of the cluster varies within Z = 0, +/- 1. The conformers of the small cluster, Au-Z-(NH3)(2), and of the nanometric size one, Au-20(Z), are chosen as illustrative examples. The dependence of the bonding patterns on the overall charge state of the cluster allows to implement the logic gates NOT, FAN-OUT, AND, NAND, OR, NOR, INH, XOR, and XNOR and to identify the outputs using an IR readout protocol. [less ▲]

Detailed reference viewed: 13 (3 ULg)
Full Text
Peer Reviewed
See detailThe magic gold cluster AU(20)
Kryachko, Eugène ULg; Remacle, Françoise ULg

in International Journal of Quantum Chemistry (2007), 107(14), 2922-2934

The 20-nanogold cluster Au-20 exhibits a large variety of two- and three-dimensional isomeric forms. Among them is the ground-state isomer Au-20(T-d) representing the stable cluster with a unique ... [more ▼]

The 20-nanogold cluster Au-20 exhibits a large variety of two- and three-dimensional isomeric forms. Among them is the ground-state isomer Au-20(T-d) representing the stable cluster with a unique tetrahedral shape, with all atoms on the surface, and large HOMO-LUMO gap which even slightly exceeds that of the buckyball fullerene C-60. The anionic cluster Au-20(-) (T-d) that holds its parent tetrahedral symmetry features a high catalytic activity. The list of the properties of the 20-nanogold clusters surveyed in the present work ranges from the energetic order of stability of its isomers to the optical absorption and excitation spectra of the Au-20(T-d) cluster. We also report the structures and properties of its doubly charged clusters Au-20(2+) and Au-20(2-) and computationally confirm that Au-20 is indeed stable. The zero-point-energy-corrected adiabatic second electron affinity of Au-20(T-d) amounts to 0.43-0.53 eV that is consistent with the experimental data. In addition, we provide computational evidence of the existence of the novel, hollow cage isomer of Au-20 and analyze its key properties. (C) 2007 Wiley Periodicals, Inc. [less ▲]

Detailed reference viewed: 48 (1 ULg)
Full Text
Peer Reviewed
See detailCharge distribution in 3'-deoxythymidine-fullerene: Mass spectrometry, laser excitation, and computational studies
Greisch, Jean-François ULg; Weinkauf, R.; De Pauw, Edwin ULg et al

in Israel Journal of Chemistry (2007), 47(1), 25-35

Electrospray ionization of the donor-spacer-acceptor model system 3'-imino[60]fulleryl-3'-deoxythymidine molecule (FdT) produces deprotonated negatively charged species (dFdT). In this paper, we ... [more ▼]

Electrospray ionization of the donor-spacer-acceptor model system 3'-imino[60]fulleryl-3'-deoxythymidine molecule (FdT) produces deprotonated negatively charged species (dFdT). In this paper, we investigate where the negative charge is localized and whether its location can be manipulated. The fragmentation of dFdT is studied experimentally by mass spectrometry using both collisional and photoactivation. Besides fragmentation, photoexcitation of anions stored in an ion trap leads to electron photodetachment. The competition between the two channels is studied as a function of the excitation wavelength. Starting from the neutral parents, two families of dFdT molecules are computationally identified. Deprotonation takes place on the 3'-deoxythymidine (dT) subunit, either on the thymine at N3 or on the deoxyribose residue at O5'. Deprotonation in N3 leads to negatively charged molecules with an extended geometry and the excess charge largely localized on the dT. The O5'-deprotonation leads to lower-energy folded conformers stabilized by an additional bond (C-O or C-H) with the nearby C-60-N acceptor part, and the negative charge is mostly localized on the fullerene. The calculated electron detachment energies are higher for the extended N3dFdT conformers than for the O5'dFdT ones. Multiphoton photodetachment experiments at 1064 nm indicate the negative charge to be on the C-60 unit. No indication for a photoinduced charge transfer was found. In MS beside the C-60 anion a C60NH, - fragment is observed, which implies a double intramolecular H transfer. The computed energy of the corresponding dFdT, stabilized by two H-C-60 bonds, is intermediate between N3 and O5' deprotonated molecules. [less ▲]

Detailed reference viewed: 28 (2 ULg)
Full Text
Peer Reviewed
See detailThe gold-ammonia bonding patterns of neutral and charged complexes Au m 0+/-1-(NH3)n. I. Bonding and charge alternation.
Kryachko, Eugène ULg; Remacle, Françoise ULg

in Journal of Chemical Physics (2007), 127(19), 194305

The gold-ammonia bonding patterns of the complexes which are formed between the ammonia clusters (NH/sub 3/)/sub 1<or=n<or=3/ and gold clusters of different sizes that range from one gold atom to the tri ... [more ▼]

The gold-ammonia bonding patterns of the complexes which are formed between the ammonia clusters (NH/sub 3/)/sub 1<or=n<or=3/ and gold clusters of different sizes that range from one gold atom to the tri-, tetra-, and 20-nanogold clusters are governed by two basic and fundamentally different ingredients: the anchoring Au-N bond and the nonconventional N-H ... Au hydrogen bond. The latter resembles, by all features, a conventional hydrogen bond and is formed between a typical conventional proton donor N-H group and the gold cluster that behaves as a nonconventional proton acceptor. We provide strong computational evidence that the gold-ammonia bonding patterns exhibit distinct characteristics as the Z charge state of the gold cluster varies within Z=0,+/-1. The analysis of these bonding patterns and their effects on the N-H ... N H-bonded ammonia clusters are the subject of this paper. [less ▲]

Detailed reference viewed: 24 (3 ULg)