**Infrared Spectroscopy**

IR spectroscopy was used to understand the probable intermolecular interactions present in the eutectic system. The observed IR spectra of AMG, the coformers and the respective eutectic systems are presented in Figure 4. As seen, the IR spectra of the eutectic systems are comparable with their starting components. No new peak was observed in the three eutectic systems and the spectra simply overlap with the spectra of the individual components. All the characteristic vibrational bands of AMG and the coformers are observed in the spectrum of the eutectic composition. For the AMG spectrum, the N−H starching peak is observed at 3470 cm−1, and the C=O stretch vibration is observed at 1713 cm−1. The slight shifting of C=O peaks in the mixture's absorption bands around <sup>1713</sup>−15 cm−<sup>1</sup> might be caused by the long-range interaction between the carbonyl groups and other functionality in the molecules in the eutectic mixture.

**Figure 4.** Comparison of FT-IR spectra of starting materials AMG and coformer with their respective eutectic composition for (**a**) AMG and CAF, (**b**) AMG and NIC, and (**c**) AMG and ZMD.
