Theoretical studies have been carried out to investigate the unusual reactivity of Ag15 + cations with oxygen. Our previous work has shown that the reactivity of free metal clusters with oxygen entails a spin excitation that causes reduced reactivity in clusters with filled electronic shells and large HOMO-LUMO gaps. Earlier experiments on Ag15 + have shown that the cluster exhibits remarkable ...

In the quantum theory ·of the electrnnic st:riucture of molecules, · the diffe., rence between the energy of the highest occupied molecular orbital (HOMO) and the energy of the lowest unoccupied molecular orbital (LUMO) the so-called »HOMO-LUMO separation« plays an important role1 • We shall denote this quantity by S. Relatively little has been done tin elucidating the relationship between mole...

AIDS is a pandemic responsible for more than 35 million deaths. The emergence of resistant mutations due to drug use is the biggest cause of treatment failure. Marine organisms are sources of different molecules, some of which offer promising HIV-1 reverse transcriptase (RT) inhibitory activity, such as the diterpenes dolabelladienotriol (THD, IC50 = 16.5 µM), (6R)-6-hydroxydichotoma-3,14-diene...

The main interaction between pyridine and zeolites leads to form a hydrogen bond between the N atom of pyridine and OH groups of zeolites. The present work reports a theoretical study about the structural, vibrational and topological properties of the charge distribution of the molecular complexes between pyridine and a series of acids sites of zeolites. The calculated structural parameters...

We describe the design and synthesis of a new graphene ribbon architecture that consists of perylenediimide (PDI) subunits fused together by ethylene bridges. We created a prototype series of oligomers consisting of the dimer, trimer, and tetramer. The steric congestion at the fusion point between the PDI units creates helical junctions, and longer oligomers form helical ribbons. Thin films of ...

We propose a third-order time-dependent perturbation theory approach to describe the chemical surfaceenhanced Raman spectroscopy of molecules interacting with two-dimensional (2D) surfaces such as an ideal 2D metal and graphene, which are both 2D metallic monolayers. A detailed analysis is performed for all the possible scattering processes involving both electrons and holes and considering the...

In this study, reactions of the simple cycloalkynes with substituted Nitrile Oxides, by DFT method will be discussed. The investigation of the structural properties, theoretical thermodynamic and kinetic data, i.e., the activation free energies(DG*), the free energies changes of reaction(DrG) and rate constants of the reactions (k) in 298 K and effects of Electron-withdrawing and...