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...

Using photoelectron spectroscopy and first principles molecular orbital calculations, we report the first observation of an abrupt change in the electronic structure of W4O m (m6 6) clusters at m 1⁄4 5 which is well below the bulk stoichiometric composition of tungsten oxide (WO3). The signature of this onset is established from an anomalous increase in the vertical detachment energies (VDE), a...

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...

We report here the synthesis of three novel pi-conjugated heterocyclic mixed trimers that contain two electron-donating 3,4-ethylenedioxy-2-thienyl (EDOT) units covalently attached to a central proquinoid electron-accepting thienopyrazine moiety (two of these narrow-HOMO-LUMO gap D-A-D compounds also bear hexyl side chains attached either to the outermost alpha positions of the EDOT end rings o...

Clusters in Physics The properties of elements from atoms to bulk can be divided into two regimes: (i) a scalable regime where properties vary smoothly as some power law until they reach the bulk limit and (ii) a nonscalable regime where the variation is highly nonmonotonic (1). In this latter region, characterized by clusters, unusual things can and often do arise because of quantum confinemen...

A new chromophore HK containing the cis,cis-1,7-diethoxy-3-isopropyljulolidine group as a novel electron-donor, thiophene as a π-conjugated bridge and a tricyanofuran (TCF) acceptor has been synthesized and systematically investigated in this paper. Its corresponding chromophore FTC using 4-(diethyl amino)benzyl as the electron donor group was also prepared for comparison. This is the first tim...

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, gap of energy, and δnmax were calculated   by support of...

We propose a series of icosahedral matryoshka clusters of A@B12@A20 (A = Sn, Pb; B = Mg, Zn, Cd), which possess large HOMO-LUMO gaps (1.29 to 1.54 eV) and low formation energies (0.06 to 0.21 eV/atom). A global minimum search using a genetic algorithm and density functional theory calculations confirms that such onion-like three-shell structures are the ground states for these A21B12 binary clu...