A Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TDDFT) Study on Optical Transitions in Oligo(p-phenylenevinylene)−Fullerene Dyads and the Applicability to Resonant Energy Transfer

Abstract

The optical transitions of three different size oligo(p-phenylenevinylene)-fullerene dyads (OPV(n)-MPC(60); n = 2-4) and of the corresponding separate molecules are studied using density functional theory (DFT) and time-dependent density functional theory. The DFT is used to determine the geometries and the electronic structures of the ground states. Transition energies and excited-state structures are obtained from the TDDFT calculations. Resonant energy transfer from OPV(n) to MPC(60) is also studied and the Fermi golden rule is used, along with two simple models to describe the electronic coupling to calculate the energy transfer rates. The hybrid-type PBE0 functional is used with a split-valence basis set augmented with a polarization function (SV(P)) in calculations and the calculated results are compared to the corresponding experimental results. The calculated PBE0 spectra of the OPV(n)-MPC(60) dyads correspond to the experimental spectra very well and are approximately sums of the absorption spectra of the separate OPV(n) and MPC(60) molecules. Also, the absorption energies of OPV(n) and MPC(60) and the emission energies of OPV(n) are predicted well with the PBE0 functional. The PBE0 calculated resonant energy transfer rates are in a good agreement with the experimental rates and show the existence of many possible pathways for energy transfer from the first excited singlet states of the OPV(n) molecules to the MPC(60) molecule.

Linear and nonlinear optical properties of triphenylamine-functionalized C60: insights from theory and experiment

“…[5][6][7][8] For these reasons, photophysical properties of fullerene derivatives are being extensively studied. [9][10][11][12][13] As it was repeatedly pointed out by several authors, 6,9 high efficiency of intersystem crossing between the singlet and the triplet excited state can be achieved in the case of C 60 . It might be further increased by the heavy-atom effect.…”

Plasmons in molecules: Microscopic characterization based on orbital transitions and momentum conservation

“…24,[34][35][36][37][38][39][40][41][42] and molecules (e.g., Refs. 33,[43][44][45][46][47][48][49][50][51][52]. Most of these studies are based on applications of TDDFT methods [53][54][55] or the RPA.…”

Fullerene‐Filled Stilbene Stars: The Balance between Isolated C60 Helices and 3D Networks in Liquid‐Crystal Self‐Assemblies

“…[27] The result for S2F2 would not be surprising for two individual chromophores, connected through spacers of different lengths, considering that the nonradiativee nergy transfer by either Fçrster or Dexter mechanisms is distance-dependent. [28,34] However,t he present case is differentb ecause 1) the NMR spectroscopy clearly demonstrates that in solution the fullerene of S2F2 is located in the vicinity of the electron-rich peripheral aryl group of one single arm and 2) the meta-substituted conjugated stars possess three almost independent chromophores. [20] If the excited chromophore is not the branch at which the fullerene is located, the distance between the centers of chromophores is about 24.0 and, thus, in the range of the fullerened istance for the largests pacer S2F14.T herefore, the fluorescence quenching for S2F2 was expectedt ob ea pproximately as efficient as for S2F8 or S2F14.T he much lower residual emission for S2F2 (lower by af actor of eight) indicates that an energy transfer between the arms plays also ar ole in this process.…”

“…[21] Furthermore, the combination of the conjugated oligo(phenylene vinylene) units with fullerenes wasc omprehensivelys tudied with respect to its energy and charge transfer from the stilbenoid donor to the fullerenea cceptor. [22][23][24][25][26][27][28] The dyad of ab ranched dendritic topology with af ullerene at the focal position has been highlighted as al ight-harvesting system. [27] Thus, the here reported combination is attractive for future studies towards possible applicationsinorganic electronics using liquid-crystalline materials.…”