Tunable Monooxime Hydrazide–hydrazone Ligands with Potential Sensing Applications: Synthetic Challenges and Optical Characterization

This research addresses the preparation of naphthalene monoxime hydrazide-hydrazones by traditional and innovative synthetic methods. The direct reaction between the corresponding carboxylic acid and hydrazine in the presence of <i>N</i>,<i>N'</i>-carbonyldiimidazole as the coupling agent outperformed the traditional approach. The obtained compounds exhibited very high molar absorptivity values associated with extended π-systems. Computational analysis provided insights into reactivity trends and electronic transitions involved in optical properties, shedding light on the future design of efficient metal ion sensors.