Combined TD-DFT-SOS-CIS(D) Study of BOPHY Derivatives with Potential Application in Biosensing

Abstract

A set of 13 bis(difluoroboron)-1,2-bis((pyrrol-2-yl)methylene)hydrazine (BOPHY) dyes is studied through a hybrid time-dependent density functional theory (TD-DFT)-scaled opposite spin-configuration interaction singles with a double correction [SOS-CIS(D)] approach accounting for solvent effects, to shed light onto the structure-property relationships of these recently developed chromophores. In the first step, we calculate the absorption-fluorescence crossing points with refined TD-DFT models considering the influences of both vibrational and solvent contributions. We found that the systematic overestimation of the 0-0 energies is effectively reduced by combining polarizable continuum model-TD-DFT with a scaled opposite spin-configuration interaction singles with a double correction [SOS-CIS(D)]. Next, for a representative system, the vibrationally resolved spectrum within the harmonic approximation is computed on the basis of TD-DFT vibrational signatures and an excellent match with experiment is found. Finally, the influence of different lateral groups on the spectroscopic properties is rationalized by investigating charge transfer parameters and examining electronic density difference maps. It is found that one can tune the position of the absorption/emission maxima by a judicious choice of the lateral substituents or by using π-extended segments. The largest absorption and emission wavelengths as well as the largest Stokes shifts are obtained for BOPHYs containing strong electron-donor dimethylaminophenyl groups attached to the α-positions of the pyrrole units through vinyl linkers, making these chromophores promising candidates for bioluminescence applications.

Optical spectroscopic properties recorded for simple BOPHY dyes in condensed media: The mirror-symmetry factor

“…This gives access to BOPHY derivatives absorbing in the far-red region. Theoretical studies have described [9] how various substituents located at different sites on the BOPHY core interact to push the absorption transitions towards lower energy. Intersystem-crossing to the corresponding triplet-excited state, which is ineffective for the parent compound, can be promoted by incorporation of iodine atoms in the central BOPHY core [10].…”

Asymmetrical benzo[a]-fused N2O2-boron-chelated BODIPYs as red to near-infrared absorbing chromophores: synthesis, characteristics and device applications for opto-electronics

“…In order to visualize the electron-density redistribution during the HOMO → LUMO transition, electron density difference plots (EDD) were employed ( Fig. 6), 91 3-thiophene ring during the transition is larger than that of the 5-thiophene ring, indicating that introduction of the thiophene donor at the 3 position in dye 2 is more effective than that at the 5 position in 3. Accordingly, 3-thiophene dye 2 has a higher-lying HOMO than stereoisomer 3, which is consistent with the CV data.…”

A comparison of methods for theoretical photochemistry: Applications, successes and challenges

“…It was found that SFPCIS is capable of qualitatively reproducing conical intersections and general potential energy surface characteristics, as computed using full configuration-interaction (FCI). Chibani et al 47,48 and Ponce-Vargas et al 49 have applied SOS-CIS(D) to large, highly π-conjugated boron containing dyes. In these three studies, SOS-CIS(D) energies are used to correct overestimated TD-DFT excitation energies, while keeping several key features that are better captured by TD-DFT; e.g.…”