Malonitrile bearing compounds are instead not isomerizing but behaves as excellent PTT agents. Indeed, irradiation at 470 nm in DMSO leads to a temperature increase up to more than 50°C for compounds 6a-c and more than 70°C for 6d. Moreover, this temperature rise is proportional to the chromophore concentration and the laser irradiance. All the compounds present attractive photothermal conversion efficiencies ranging from 28% to 50% and good photothermal resistance. Hence, we believe that our molecular design has highlighted the competition between the different relaxation pathways: fluorescence, isomerization, and heat production. More importantly, we have shown how the precise choice of the peripheral substituents may favor one relaxation channel, hence driving and tuning a proper photochemical response. The possibility of obtaining biomimetic photoswitches or photothermal agents with well-defined properties indicates that our two families of compounds are promising for further applications in the biomedical field, especially due to their non negligible cross section in absorbing two photons in the NIR region. Moreover, some antennas system to switch absorption in the visible or infrared portion of the spectrum could also be considered.