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In this work, we looked at how to make fluorescence hybrid poly(amidoamine) dendrimer (PAMAM) dendrimers using calcozine red 6G and coumarin end groups. After synthesis of ethylenediamine (EDA)-cored 4th generation PAMAM dendrimer (G4.0), surface functional groups is reacted with calcozine red 6G (Rh6G) and 7-methacryloyloxy-4-methylcoumarin. Fourier transform infrared spectroscopy, proton nuclear magnetic resonance ( 1 H NMR), and X-ray diffraction are used to characterize the structure of synthesized fluorescent hybrid dendrimers. Optical properties are demonstrated using a fluorescence spectrophotometer, and UV-Vis-NIR reflectance spectra. According to UV-Vis-NIR reflectance spectra, hybrid dendrimers were transparent in the NIR range. Moreover, quantum yield (Φs) of hybrid dendrimers was calculated in dimethylformamide (DMF), ethanol, dimethyl sulfoxide (DMSO), and distilled water (H 2 O). Dendrimers in which Rh6G was utilized to modification showed the maximum quantum yield in ethanol due to great interaction of structure with ethanol and the arrangement of ring-opened amide shape of calcozine red 6G., (© 2022. The Author(s).)

Rhodamine 6G (Rh6G) is modified by ethylenediamine to obtain rhodamine with amine functional groups (Rh6G-NH 2 ). Rh6G-NH 2 as an initial core is used to bond coumarin derivatives. Synthesized fluorescent colorants are specified using Fourier transform infrared spectroscopy (FT-IR), proton and carbon nuclear magnetic resonance ( 1 H NMR and 13 C NMR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) to analyze the structure of the fluorescent pigments. Fluorescence microscopy, fluorescence spectrophotometer, and UV-visible-NIR reflectance spectra are used to demonstrate the optical properties. UV-Vis-NIR reflectance spectra showed that synthesized colorants were transparent in NIR region. Also, photophysical properties of 2-(4-methyl-2-oxo-2H-chromen-7-yloxy) acetic acid (MOHCYAA), Rh6G-NH 2 , and hybrid 2-(4-methyl-2-oxo-2H-chromen-7-yloxy) acetic acid/rhodamine 6G (HMR) were investigated. Type of solvent had a strong effect on quantum yield. Rh6G-NH 2 (ϕ s  = 0.66) and HMR (ϕ s  = 0.72) displayed the maximum quantum yield in ethanol due to good interaction with ethanol and the formation of ring-opened amide form of rhodamine group. Finally, Rh6G-NH 2 and HMR displayed the maximum quantum yield in ethanol due to good interaction of structure with ethanol and the formation of ring-opened amide form of rhodamine group in compound., (© 2022. The Author(s).)