Near-infrared absorption and photothermal properties of heptamethine pyrylium dyes with bistriflimide anion

Investigation of near-infrared absorption properties by the GW–BSE method in heptamethine pyrylium dyes

“…2 shows the absorption spectra of TBCY-5 and TBCY-6 that were calculated using the GW–BSE method. The peaks and shape of the GW–BSE absorption spectra of TBCY-5 and TBCY-6 agree well with the experiment of Vikneshvaran et al 62 Furthermore, the effect of solvent on the UV absorption spectra was investigated using VASPsol 60 in DCM solvation with a dielectric constant value of 8.93 for the whole GW–BSE procedure for TBCY-5 and TBCY-6. The GW–BSE highest absorption wavelengths of TBCY-5 and TBCY-6 were computed to be at 1010 (1003) and 977 (968) nm in DCM solution (vacuum), respectively, which agrees well with those reported in the experimental database 37 for DCM solution at 1010 nm and 989 nm.…”

“…The GW-BSE highest absorption wavelengths of TBCY-5 and TBCY-6 were computed to be at 1010 (1003) and 977 (968) nm in DCM solution (vacuum), respectively, which agrees well with those reported in the experimental database 37 for DCM solution at 1010 nm and 989 nm. In the NIR-I region, the computed absorption peak of TBCY-5 (TBCY-6) is at 855 nm (818 nm) in a vacuum and 861 nm (819 nm) in DCM medium, whereas the experimentally observed peak 37 in DCM solution is at approximately 900 nm Fig. 2 The optical absorption spectra of TBCY-5 and TBCY-6 (a) were calculated using the GW-BSE method in vacuum and also obtained (b) from the experimental work of Vikneshvaran et al in DCM solution.…”

“…These compounds showed the highest absorption wavelength at 1030 and 1007 nm in o -DCB solution for the TBCY molecule with five-membered and six-membered cyclic rings in the bridge position, respectively. 37 The red-shift observed after modifying the cyclic ring was also reported by Henary et al 38 in heptamethine cyanine dyes with different types of end groups that provide other strategies to shift the highest absorption wavelength. Therefore, in this study, we evaluate the effect of cyclic rings on the optical and electronic properties of cyanine dyes in terms of the red-shift absorption wavelength in the NIR-II region based on the GW–BSE calculation.…”

“…2 The optical absorption spectra of TBCY-5 and TBCY-6 (a) were calculated using the GW-BSE method in vacuum and also obtained (b) from the experimental work of Vikneshvaran et al in DCM solution. 62 The UV absorption spectra of (c) TBCY-5 and (d) TBCY-6 were calculated from GW-BSE calculations in vacuum and DCM solvent.…”

“…In 2020, Cosco et al 36 reported that the maximum absorption wavelength red-shift up to ∼80 nm can be obtained by changing the substituted functional group on the pyrylium heterocycles. On the other hand, Vikneshvaran et al 37 synthesized a modified version of Flav7, called the heptamethine pyrylium dye with tert -butyl substitution (TBCY), which contains a heptamethine chain with different modifications of the cyclic ring and pyrylium heterocycles with tert -butyl substitution as the end groups. These compounds showed the highest absorption wavelength at 1030 and 1007 nm in o -DCB solution for the TBCY molecule with five-membered and six-membered cyclic rings in the bridge position, respectively.…”