The main photophysical properties of a series of recently synthetized 1,2- and 1,3-squaraines, including absorption electronic spectra, singlet-triplet energy gaps, and spin-orbit matrix elements, have been investigated by means of density functional theory (DFT) and time-dependent DFT approaches. A benchmark of three exchange-correlation functionals has been performed in six different solvent ...

With the aim of recognizing the steric effects on the silylenic R2C6H6Si structures, DFT calculationsare carried out on 8 structures of R2C6H6Si (where R is hydrogen (H), methyl (Me), isopropyl (i-pro),and tert-butyl (tert-Bu)). These species are at either triplet (t) or singlet (s) states. Singlet–tripletenergy separations ( Me (20.32) > t-Bu (15.92).all singlet states of R2C6H6Si, are more st...

Using Hartree-Fock Su-Sheriffer-Heeger (HF-SSH) model, we have studied the dependence of the energies of the ground (magnetic triplet state) and the first exited (nonmagnetic singlet state) states of the size-2 trigonal zigzag graphene nanoflake (size-2 NF) on the intensity of an external in plane static electric field at zero temperature. We identify a transition from the magnetic triplet stat...

Multiwavelength time-resolved spectroscopy is employed to study the triplet-state photophysics of acridine yellow dissolved in a rigid saccharide glass. Activated reverse intersystem crossing from photoexcited triplet states to the fluorescent singlet state provides a temperaturedependent decay pathway of the triplet population. While a unimolecular relaxation of a homogeneous excited triplet p...

The electronic state orderings and energies of heteroaryl oxenium ions were computed using high-level CASPT2//CASSCF computations. We find that these ions have a number of diverse, low-energy configurations. Depending on the nature of the heteroaryl substituent, the lowest-energy configuration may be open-shell singlet, closed-shell singlet, or triplet, with further diversity found among the su...

The interpretation of the ultrafast luminescence decay in [Re(Br(CO)3(N^N)] complexes as a new group of chromophoric imidazo[4,5-f]-1,10-phenanthroline ligands, including 1,2-dimethoxy benzene, tert-butyl benzene (L4) and 1,2,3-trimethoxy benzene, tert-butyl benzene (L6), was studied. Fac-[Re(Br(CO)3L4 and L6] with different aryl groups were calculated in singlet and triplet excited states. The...

with the aim of recognizing the steric effects on the silylenic r2c6h6si structures, dft calculationsare carried out on 8 structures of r2c6h6si (where r is hydrogen (h), methyl (me), isopropyl (i-pro),and tert-butyl (tert-bu)). these species are at either triplet (t) or singlet (s) states. singlet–tripletenergy separations ( me (20.32) > t-bu (15.92).all singlet states of r2c6h6si, are more st...

We report singlet and triplet state splittings (I:J.EsT) for fluorine-substituted methylenes and silylenes using dissociation-consistent configuration interaction (CI) (based on generalized valence bond wave functions). These relatively simple CI calculations emphasize correlation consistency between the singlet and triplet states. Values of I:J.Esr for CH2, CF2, SiH2, and SiF2 are in excellent...

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...