Results 221 to 230 of about 18,272 (254)

Novel cyclopentadithiophene dimers with small HOMO-LUMO gaps

Synthetic Metals, 2003
Cyclopentadithiophene dimers containing 1,3-dioxalane, ketone, or dicyanovinylene as bridging groups showed red-shifted absorption compared to quaterthiophene in their UV-vis-NIR spectra and bridging groups have large influence on the reduction potentials but not on the oxidation potentials.
M. Kozaki, Y. Yonezawa, H. Igarashi, K. Okada   +3 more
openaire   +1 more source

A Modular Access to Divinyldiphosphenes with a Strikingly Small HOMO–LUMO Energy Gap

Chemistry – A European Journal, 2019
AbstractThe olefinic C−H bond functionalization of (NHC)CHPh (NHC=IPr=C{(NAr)CH}2 1; SIPr=C{(NAr)CH2}2 2; Ar=2,6‐iPr2C6H3), derived from classical N‐heterocyclic carbenes (NHCs), with PCl3 affords the dichlorovinylphosphanes {(NHC)C(Ph)}PCl2 (NHC=IPr 3, SIPr 4).
Ghadwal, Rajendra, Rottschäfer, Dennis, Sharma, Mahendra Kumar, Neumann, Beate, Stammler, Hans-Georg, Andrada, Diego   +5 more
openaire   +3 more sources

From Oligomers to Polymer:  Convergence in the HOMO−LUMO Gaps of Conjugated Oligomers

Organic Letters, 2006
[Structure: see text] Extrapolation of HOMO-LUMO gaps for pi-conjugated oligomers at the B3LYP/6-31G(d) level of theory predict accurately (within 0.1-0.2 eV) the band gaps of conjugated polymers only when long (at least 20-mer) pi-conjugated oligomers are used for the extrapolation.
Sanjio S, Zade, Michael, Bendikov
openaire   +2 more sources

Linking the HOMO-LUMO gap to torsional disorder in P3HT/PCBM blends

The Journal of Chemical Physics, 2015
The electronic structure of [6,6]-phenyl C61 butyric acid methyl ester (PCBM), poly(3-hexylthiophene) (P3HT), and P3HT/PCBM blends is studied using soft X-ray emission and absorption spectroscopy and density functional theory calculations. We find that annealing reduces the HOMO-LUMO gap of P3HT and P3HT/PCBM blends, whereas annealing has little effect
John A. McLeod, Amy L. Pitman, Ernst Z. Kurmaev, Larisa D. Finkelstein, Ivan S. Zhidkov, Achilleas Savva, Alexander Moewes   +6 more
openaire   +3 more sources

Effect of Substitution on the Optical Properties and HOMO−LUMO Gap of Oligomeric Paraphenylenes

The Journal of Physical Chemistry A, 2010
A series of dialkyl amino benzophenone dimers with various alkyl chain lengths is presented. Gaussian B3LYP/6-31G(d) calculations show that the band gap decreases within the dimer series as a function of the donor group efficiency. Theoretical calculations show that the interaction between phenyl-phenyl rings is more important than simple donor ...
Brian D, Koepnick, Jeremy S, Lipscomb, Darlene K, Taylor   +2 more
openaire   +2 more sources

Tuning the Homo–Lumo Gap in Π-Bridged Bis(Phosphaalkenes)

Phosphorus, Sulfur, and Silicon and the Related Elements, 2013
Abstract The HOMO–LUMO gap in a series of π-bridged bis(phosphaalkenes) is investigated by theoretical methods. The deshielding of the experimental 31P-NMR chemical shifts of a selection of these compounds does not correlate with a decrease of their calculated HOMO–LUMO gaps.
Andreas Orthaber, Rudolf Pietschnig
openaire   +1 more source

HOMO–LUMO Gaps of Homogeneous Polycyclic Aromatic Hydrocarbon Clusters

The Journal of Physical Chemistry C, 2019
Recent UV–visible absorption spectral analyses of a series of flame-formed carbon nanoparticles show that these particles exhibit behaviors that can be closely described by the quantum confinement ...
Dongping Chen, Hai Wang
openaire   +1 more source

Thermal routes to low HOMO–LUMO energy gap poly(arylenevinylene)s

Journal of Materials Chemistry, 2001
We have prepared poly(2,5-dimethoxy-1,4-phenylenevinylene) (DMEOPPV) and poly (2,5-thienylenevinylene) (PTV) via xanthate precursor polymer routes. The respective precursor polymers can be thermally converted to their corresponding conjugated polymers without the need for acid catalysis.
Mitchell, William J., Pena, Christophe, Burn, Paul L.   +2 more
openaire   +4 more sources

Tuning the HOMO–LUMO gap of SiC quantum dots by surface functionalization

Chemical Physics Letters, 2012
Abstract We present density-functional theoretical results of structural, electronic and optical properties of bare and surface passivated (–H, –OH, –NH 2 ) stoichiometric Si n C n ( n  = 10, 16, 28, 37, 43, 55, 68) quantum dots (QDs) as a function of the size of the dots.
Supriya Saha, Pranab Sarkar
openaire   +1 more source

Tuning the HOMO–LUMO Energy Gap of Small Diamondoids Using Inverse Molecular Design

Journal of Chemical Theory and Computation, 2017
Functionalized diamondoids show great potential as building blocks for various new optoelectronic applications. However, until now, only simple mono and double substitutions were investigated. In this work, we considered up to 10 and 6 sites for functionalization of the two smallest diamondoids, adamantane and diamantane, respectively, in search for ...
Jos L. Teunissen, Frank De Proft, Freija De Vleeschouwer   +2 more
openaire   +3 more sources