Benzo[c][1,2,5]thiadiazole Donor–Acceptor Dyes: A Synthetic, Spectroscopic, and Computational Study

Abstract

The synthesis, optical characterization and computational modeling of seven benzo[c][1,2,5]thiadiazole (BTD) donor-acceptor dyes are reported. These dyes have been studied using electrochemical analysis, electronic absorption, emission, and Raman and resonance Raman spectroscopies coupled with various density functional theoretical approaches. Crystal structure geometries on a number of these compounds are also reported. The optical spectra are dominated by low energy charge-transfer states; this may be modulated by the coupling between donor and acceptor through variation in donor energy, variation of the donor-acceptor torsion angle, and incorporation of an insulating bridge. These modifications result in a perturbation of the excitation energy for this charge-transfer transition of up to ∼2000 cm(-1). Emission spectra exhibit significant solvatochromisim, with Lippert-Mataga analysis yielding Δμ between 8 and 33 D. Predicted λmax, ε, and Raman cross sections calculated by M06L, B3LYP, PBE0, M06, CAM-B3LYP, and ωB97XD DFT functionals were compared to experimental results and analyzed using multivariate analysis, which shows that hybrid functionals with 20-27% HF best predict ground state absorption, while long-range corrected functionals best predict molecular polarizabilities.

The influence of driving force on intramolecular electron transfer: A theoretical study of subphthalocyanine‐AzaBODIPY‐C60 supramolecular triad

“…Ever since the method of making electron‐rich donor and electron‐deficient acceptor fused (donor‐acceptor: D‐A) to build a new material has been reported by Havinga et al in 1993, the way leads new possibilities in the field of organic solar cell . Recently, organic small molecules (OSMs) having donor‐acceptor structures exhibit excellent photoelectric properties . Currently, the photoelectric conversion efficiency (PCE) of OSM‐based solar cell has reached 9.44% by using D‐A small molecule as an donor, and the PCE of OSM‐based solar cell using D‐A small molecule as a acceptor has reached at 14.2% .…”

Modulation of Donor-Acceptor Distance in a Series of Carbazole Push-Pull Dyes; A Spectroscopic and Computational Study

“…While a wide range of different donor (carbazole [ 11 , 12 , 13 ], triphenylamine [ 14 , 15 , 16 ], dimethylaniline [ 17 , 18 ], fluorene [ 13 ] and coumarin [ 17 ]) and acceptor (benzothiadiazole [ 13 , 15 ], hexaazatrinaphthalene [ 16 ], napthlenediimides [ 19 ], dipyridophenazine [ 20 ] and cyanoacrylic acid [ 21 ]) moieties have been studied this work focuses on the carbazole donor, cyanoacrylic acid acceptor combination. The use of this donor acceptor pairing has been used in a number of studies in the literature [ 12 , 22 , 23 , 24 , 25 ].…”

Synthesis and Light‐Harvesting Potential of Cyanovinyl β‐Substituted Porphyrins and Dyads

“…Resonance Raman spectra were recorded with a system reported previously . In short, the excitation beam focussed onto the sample with an obtuse‐angle backscattering geometry.…”