An electrical and optical energy gaps separation strategy is put forward for the design of organic wide bandgap semiconductors. This new principle could achieve optimization of wide bandgap (both high singlet and triplet energies) and favorable carrier injection energy levels simultaneously.

Ab initio electronic structure theory has been applied to predict the structures and electronic spectra of free-base porphyrin (PH2) and its meso-tetrahalogenated derivatives (m-PX8H2; X = F, Cl, Br). Structures, singlet-triplet energy gaps, and electronic spectra are predicted using the B3LYP method in conjunction with the 6-31G(d) basis set and the effective core potentials/basis sets of Stev...

In order to explain the reduced photodynamic (PDT) activity of a recently proposed m-tetra (hydroxyphenyl) porphycene derivative (temocene or THPPo) in terms of singlet oxygen quantum yields compared to porphyrin analogue Foscan (m-THPC), a time dependent DFT investigation has been carried out. Computed electronic transitions, singlet-triplet energy gaps and spin-orbit coupling matrix elements ...

Chemiluminescent techniques have been employed to investigate electronic energy transfer from ketone donors (acetone, acetophenone) to acceptors (e.g., 9,lO-diphenylanthracene and biphenyl) in films of polystyrene and polymethyl methacrylate at 50 "C. Tetramethyl-l,2-dioxetane and 3,4-diphenyl-3,4-dimethyldioxetane were used to generate excited (singlet and triplet) acetone and (triplet) acetop...

A density functional theory (DFT) study of {CoNO}(8) cobalt nitrosyl complexes containing the [n,n]tropocoronand ligand (TC-n,n) has revealed a sharp reduction of singlet-triplet gaps as the structures change from near-square-pyramidal (for n = 3) to trigonal-bipyramidal with an equatorial NO (for n = 5, 6). An experimental reinvestigation of [Co(TC-3,3)(NO)] has confirmed that it is not parama...

the combined effect of hydrostatic pressure and temperature on correlation energy in a triplet state of two electron spherical quantum dot with square well potential is computed. the result is presented taking gaas dot as an example. our result shows the correlation energies are i)negative in the triplet state contrast to the singlet state ii) it increases with increase in pressure  iii)further...

The main photophysical properties of a series of expanded bacteriochlorins, recently synthetized, have been investigated by means of DFT and TD-DFT methods. Absorption spectra computed with different exchange-correlation functionals, B3LYP, M06 and ωB97XD, have been compared with the experimental ones. In good agreement, all the considered systems show a maximum absorption wavelength that falls...

The purpose of this paper has been to explore in a preliminary way the nature and mechanism of collisional energy transfer and quenching of electronic excitation. For this purpose, the Born approximation has been used, and the triplet-triplet and singlet-singlet transfer, and the triplet-triplet and singlet-singlet quenching have been studied. It has been shown theoretically that (i) the single...