Search results for "Irak"

Bush, camino del Nobel

2003

Sorprendente izquierda norteamericana

2004

La Batalla europea

2003

Integrismo político en EEUU / 2. Integrismo y tortura

2004

¿De disidentes a vasallos?

2003

Havel o la improbable pervivencia del héroe

2003

Pyrazolium- and 1,2-Cyclopentadiene-Based Ligands as σ-Donors: a Theoretical Study of Electronic Structure and Bonding

2012

A high-level theoretical investigation of 1,2-cyclopentadiene (4) was performed using density functional theory and wave function methods. The results reveal that, in contrast to earlier assumptions, the ground state of this ephemeral “allene” is carbene-like with a small diradical component. Furthermore, the electronic structure and chemistry of 4 are found to parallel that of 1,2,4,6-cycloheptatetraene: both molecules possess a low-lying excited singlet state with a closed-shell carbenic structure, enabling rich coordination chemistry. Energy decomposition analyses conducted for currently unknown metal complexes of 4 as well as those involving stable carbenes based on the pyrazolium frame…

Pagar los platos rotos

2003

Bombas y democracia

2003

Electronic Structures and Spectroscopic Properties of 6π-Electron Ring Molecules and Ions E2N2 and E42+ (E = S, Se, Te)

2004

The electronic structures and molecular properties of square-planar 6π-electron ring molecules and ions E2N2 and E42+ (E = S, Se, Te) were studied using various ab initio methods and density functionals. All species were found to contain singlet diradical character in their electronic structures. Detailed analysis of the CAS wave function of S2N2 in terms of different valence bond structures gives the largest weight for a Lewis-type singlet diradical VB structure in which the two unpaired electrons reside on nitrogen atoms, though the relative importance of the different VB structures is highly dependent on the level of theory. The diradical character in both E2N2 and E42+ was found to incr…