The degree of -electron (de)localization and aromaticity of a series of polybenzenoid hydrocarbons (PBHs) has been analyzed through the π-contribution to the electron localization function (ELFπ), calculated at the B3LYP/6-311G(d,p) hybrid density functional theory level. The extent of -electron delocalization in the various hexagons of a PBH was determined through analysis of the bifurcation...

In the mol-ecular structure of the title compound, C(13)H(18)ClNO(3), the amide group is nearly perpendicular to the benzene ring, making a dihedral angle of 85.66 (9)°. The C=O bond distance of 1.242 (3) Å and the C-N bond distance of 1.333 (3) Å suggest electron delocalization in the amide fragment. Inter-molecular O-H⋯O and N-H⋯O hydrogen bonding helps to stabilize the crystal structure.

Nonradiative decay channels in the L-edge fluorescence yield spectra from transition-metal-aqueous solutions give rise to spectral distortions with respect to x-ray transmission spectra. Their origin is unraveled here using partial and inverse partial fluorescence yields on the microjet combined with multireference ab initio electronic structure calculations. Comparing Fe2+, Fe3+, and Co2+ syst...

Rare examples of homodinuclear zwitterionic Pd(II) and Pt(II) complexes with bridging, two-coordinate P{cyclo-CH(2)N(R)CHN(R)CH(2)} ligands (R = 4-FC(6)H(4)CH(2), C(6)H(5)CH(2)) have been characterized by single-crystal X-ray diffraction using synchrotron radiation. Short N-C distances and enlarged N-C-N bond angles support electron delocalization in the central N-C-N backbone.

Stereoelectronic effects modulate molecular structure, reactivity, and conformation. We find that the interaction between the ester and carboxyl moieties of aspirin has a previously unappreciated quantum mechanical character that arises from the delocalization of an electron pair (n) of a donor group into the antibonding orbital (π*) of an acceptor group. This interaction affects the physicoche...

We report computer based simulations of energetics, spectroscopy, and electron-phonon interaction of americium using a novel spectral density functional method. This approach gives rise to a new concept of a many-body electronic structure and reveals the unexpected mixed valence regime of Am 5f6 electrons which under pressure acquire the 5f7 valence state. This explains the unique properties of...

The diradical acceptor-donor-acceptor triad 1(••), based on two polychlorotriphenylmethyl (PTM) radicals connected through a tetrathiafulvalene(TTF)-vinylene bridge, has been synthesized. The generation of the mixed-valence radical anion, 1(•-), and triradical cation species, 1(•••+), obtained upon electrochemical reduction and oxidation, respectively, was monitored by optical and ESR spectrosc...

The asymmetric unit of the title compound, C(8)H(6)N(2)O(4), contains one half-mol-ecule; a twofold rotation axis bisects the molecule. The quinoxaline ring is planar, which can be attributed to electron delocalization. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into R(2) (2)(10) motifs, leading to layers, which inter-act via phen-yl-phenyl inter-actions ...