Self-assembled-monolayers (SAMs) of aromatic thiolates on metal surfaces are candidates for molecular “quantum dots” or “wires”. We probe the interfacial electronic structure using two-photon photoemission in SAMs of pentafluorothiophenolate (C6F5S) on Cu(111). Compared to gas-phase C6F5SH, the σ* LUMO in the assembled molecule is stabilized by 3.1 eV and the HOMO-LUMO gap is reduced by 5.7 eV....

We investigate the electronic coupling between a TiO2 nanowire and a natural dye sensitizer, using state-of-the-art time-dependent first-principles calculations. The model dye molecule, cyanidin, is deprotonated into the quinonoidal form upon adsorption on the wire surface. This results in its highest occupied molecular orbital (HOMO) being located in the middle of the TiO2 bandgap and its lowe...

The introduction of electron donor and acceptor groups at strategic locations on a fluorogenic cyanine dye allows fine-tuning of the absorption and emission spectra while preserving the ability of the dye to bind to biomolecular hosts such as double-stranded DNA and a single-chain antibody fragment originally selected for binding to the parent unsubstituted dye, thiazole orange (TO). The observ...

The central component of the programmable molecular switch recently demonstrated by Stoddart and Heath is [2]rotaxane, which consists of a cyclobis(paraquat-p-phenylene) shuttle (CBPQT(4+))(PF(6)(-))(4) (the ring) encircling a finger and moving between two stations, tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP). As a step toward understanding the mechanism of this switch, we report he...

Heteroleptic (CN)2Ir(acac) (C ∧N = 4-CBppy (1); 5-CBppy (2), 4-fppy (4) CB = ortho-methylcarborane; ppy = 2-phenylpyridinato-C,N, 4-f ppy = 2-(4-fluorophenyl)pyridinato-C,N, acac = acetylacetonate) complexes were prepared and characterized. While 1 exhibits a phosphorescence band centered at 531 nm, which is red-shifted compared to that of unsubstituted (ppy)2Ir(acac) (3) (λem = 516 nm), the em...

in this work, the effects of as-doped on the adsorption of oxygen gas on the outer and inner surface ofboron nitride nanotube (bnnts) is investigated. the structural parameters, quantum properties involving:bond length, bond angle, homo-lumo orbital, gapenergy, electron affinity, electronegativity, chemicalpotential, global hardness, global softness and nmr parameters of bnnts are calculated at...