X-ray absorption/emission spectroscopy (XAS/XES) at the N K-edge of iron protoporphyrin IX chloride (FePPIX-Cl, or hemin) has been carried out for dissolved monomers in DMSO, dimers in water and for the solid state. This sequence of samples permits identification of characteristic spectral features associated with the hemin intermolecular bonding. These characteristic features are further analy...

Quantum mechanics has provided chemistry with two general theories, valence bond (VB) theory and molecular orbital (MO) theory. The two theories were developed at about the same time, but quickly diverged into rival schools that have competed, sometimes fervently, on charting the mental map and epistemology of chemistry. Three practitioners of MO and VB theory talk - fighting a little, trying t...

We present a critical theoretical study of electronic properties of silicon nanoclusters, in particular the roles played by symmetry, relaxation, and hydrogen passivation on the the stability, the gap states and the energy gap of the system using the order-N [O(N)] non-orthogonal tight-binding molecular dynamics and the local analysis of electronic structure. We find that for an unrelaxed clust...

For analyzing of compositions molecular orbitals in this article in order to combination only- xylometazolin-C7 X2 (XY) and C60– xylometozolin-C65-X2 (FXY), first got energies of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) by using NBO analyze in Gaussian 03 software. Then, occupancy parameter, g...

A general method for synthesizing a novel class of metalloporphyrin dimers containing unbridged metal-metal bonds is presented. By choosing the appropriate metal, the bond order in these dimers can be varied systematically. The synthesis and characterization of osmium(II) and molybdenum(II) porphyrin dimers containing the respective metal-metal double and quadruple bonds are described. A simple...

Hydrogen bonding in methanol clusters has been investigated by using inner-shell photoabsorption spectroscopy and density functional theory (DFT) calculations in the carbon and oxygen K-edge regions. The partial-ion-yield (PIY) curves of H(CH(3)OH)(n)(+) were measured as the soft x-ray absorption spectra of methanol clusters. The first resonance peak in the PIY curves, which is assigned to the ...

S are introduced to N2 and CO in general chemistry, and their prominence continues in inorganic chemistry 3 and physical chemistry. However, their isoelectronic relative, BF, is much less considered. Together, this trio of diatomic molecules comprises a series that superbly exemplifies numerous bonding and chemical trends. The changes in bonding lead to three molecules that behave very differen...

as the molecules approach under the application of pressure. We expect that high-pressure Raman study will provide further insight into the vibrational and bonding properties in solid Cso The pressure behavior of a “squashing” mode, a radial distortion from the spherical shape into an ellipsoid, is particularly interesting in comparison with the softening observed for the IF,, radial mode. A hi...

For analyzing of compositions molecular orbitals in this article in order to combination only- xylometazolin-C7 X2 (XY) and C60– xylometozolin-C65-X2 (FXY), first got energies of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) by using NBO analyze in Gaussian 03 software. Then, occupancy parameter, g...