The K-band λmax values of the ultraviolet–visible spectra of some hydrazones in ethanol by a TD-DFT/PCM approach

We presented the time-dependent density functional theory calculated ultraviolet–visible (UV-vis) spectra for derivatives of phenylhydrazones, semicarbazones and pyrrole hydrazones in ethanol. We employed the B3LYP, PBE0, CAM-B3LYP, LC–ωPBE, LC–PBE and ωB97X-D functionals. We gauged the performance of the six hybrid functionals of choice in determination of the K-band λmax values of the UV-vis spectra. The PCM-TD-PBE0/6-311+G(2d,p)//PCM-PBE0/6-311G(d,p) approach provided the smallest error with an average absolute deviation limited to 14 nm. We also investigated the impacts of including explicit solvent molecules and considering vibrational envelope with the Franck–Condon Herzberg–Teller method.