A DNA duplex was used as a scaffold to evaluate the intrinsic reactivity of [2 + 2] photodimerization between stilbene derivatives; the duplex pre-organizes the substrates avoiding the need for an association step. Unmodified stilbenes were first introduced at base-pairing positions on complementary DNA strands. The duplex was then irradiated with 340 nm UV light. HPLC analyses revealed that [2...

In this paper theoretical study by using DFT method on three conjugated compound based on 2-styryl-5-phenylazo-pyrrole is reported. These dyes contain one carboxy, two carboxy and one sulfonic acid anchoring groups, the aim is to investigate their effects on the electronic structure. The theoretical knowledge of the HOMO and LUMO energy levels of the components is cannot be ignored in investiga...

Studies using ultraviolet photoelectron spectroscopy (UPS) and density functional theory (DFT) demonstrate that M4X6 (M = W, Mo and X = O, S) clusters show large gaps (about 2 eV) between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), indicative of their high stability and chemical inertness. In particular, W4O6 has a lower symmetry and a large...

Terthiophene (3T) molecules adsorbed on herringbone (HB) reconstructed Au(111) surfaces in the low coverage regime were investigated by means of low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS) under ultra-high vacuum conditions. The 3T molecules adsorb preferentially in fcc regions of the HB reconstruction with their longer axis oriented perpendicular to the soliton w...

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 ...

The ground-state structure and frontier molecular orbital of D-π-A organic dyes, CFT1A, CFT2A, and CFT1PA were theoretically investigated using density functional theory (DFT) on B3LYP functional with 6-31G(d,p) basis set. The vertical excitation energies and absorption spectra were obtained using time-dependent DFT (TD-DFT). The adsorptions of these dyes on TiO(2) anatase (101) were carried ou...

We studied the adsorption of 4,4'-dithiodipyridine (PySSPy) on Au(111) under ultra-high vacuum conditions and at low-temperature both experimentally by means of scanning tunneling microscopy and spectroscopy (STM and STS), and theoretically by density functional theory (DFT). We find PySSPy molecules – characterized by their elongated appearance in STM – assembled in islands which reside exclus...