Structural, electronic and photovoltaic properties of pyrrole-furan copolymer incorporated with several electron-donating groups (EDGs) electron-withdrawing (EWGs) were investigated using density functional theory (DFT) time-dependent (TD-DFT). The intramolecular hydrogen bonding between the N…H site pyrrole O furan enhances a coplanar structure derivatives. substituted -NO2 shows significantly...

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...

We study Ge2O2 and Ge2O2 2 with density functional theory ~DFT! and photoelectron spectroscopy ~PES!. We find that Ge2O2 is a rhombus ~D2h), closed-shell molecule with a large HOMO-LUMO gap. The PES spectrum of Ge2O2 2 is obtained at four detachment photon energies: 1064, 532, 355, and 266 nm. Vibrational structure is resolved at the lowest photon energy with a single progression and a frequenc...

A dodecazinc silicotungstate K(20)Na(2)[Zn(6)(OH)(7)(H(2)O)(Si(2)W(18)O(66))](2)·34H(2)O (1) has been synthesized and characterized by X-ray crystallography, elemental analysis, infrared, UV-vis spectroscopy, cyclic voltammetry, acid-base titration, and DFT calculations. The twelve zinc atoms between the two [Si(2)W(18)O(66)](16-) frameworks make this complex more stable hydrolytically than the...

A detailed study of energy differences between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and water clusters is presented. Recent work questioning the applicability of Kohn-Sham density-functional theory to proteins and large water clusters (Rudberg 2012 J. Phys.: Condens. Matter 24 072202) has demonstrated vanishing HOMO-LUMO gaps for thes...

Indole-3-carbinol (I3C) is a plant compound derived from glucosinolates, found in cruciferous vegetables. Researchers have indicated that I3C shows great promise as a cancer preventative and hormone-balancing agent. HyperChem 7.5 software was used for quantum mechanical calculations. The geometry optimization was carried out using Ab Initio method. QSAR parameters were generated with semi empir...

Density functional theory calculations on the Co(2)(NO)(4)(SR)(2) compounds (R = CH(3), CF(3) and C(4)H(9)) predict butterfly and open isomeric structures with and without a direct Co-Co bond. The open Co(2)(NO)(4)(SR)(2) structures are favored over the butterfly isomers, in terms of relative energy. Furthermore the open structures are predicted to have approximately twice as large HOMO-LUMO ga...

A series of [26]hexaphyrins(1.1.1.1.1.1) bearing two α-oligothienyl substituents at 5,20-positions have been synthesised and are shown to have a dumbbell hexaphyrin conformation, to which the α-oligothienyl groups are linked with small dihedral angles to form an acyclic helix-like conjugated network. While their distinct diatropic ring currents and four reversible reduction waves characteristic...

Small molecule organic semiconductors have well-defined structures and can be used in place of polymers which often show batch-to-batch variation. Many different electron-rich donor and electrondeficient acceptor units have been used to design materials with reduced HOMO-LUMO gaps and improved mobilities. Here we introduce a novel acceptor unit, 1-dodecyl-6-dodecoxynaphthyridine-2one. This acce...