Isatin hydrazones based on phenanthroline like skeleton – synthesis

This work deals with synthesis of new arylhydrazones with phenanthroline modification of isatin with application potential for various areas of supramolecular chemistry and photochemistry. The work describes preparation of basic phenanthroline isatin skeleton, namely 5H-pyrrolo [2,3-f] [1,10] phenanthroline-6,7-dione. The work consequently describes preparation of corresponding hydrazones as new molecular switches or colorimetric fluorescent/phosporescent chemosensors [1,2]. Presence of new phenantroline-like isatin skeleton ensures the light absorption in visible (close to infrared) region of electromagnetic spectrum. The presence of new phenantroline skeleton part in new hydrazones brings strong chelatation properties with important change of emission characteristics which can be modulated by photochemical switching around hydrazone C=N bond [3,4]. Implementation of an appropriate substituent to hydrazone phenyl moiety  can significantly influence interaction of hydrazones with anions and even the photochromism of these molecules. We have successfully prepared 5 for now undescribed derivatives, with the aim to find correlation between the structure and desired properties.