*Article* **A Family of Ethyl** *N***-Salicylideneglycinate Dyes Stabilized by Intramolecular Hydrogen Bonding: Photophysical Properties and Computational Study**

**Larisa E. Alkhimova 1,\*, Maria G. Babashkina 2 and Damir A. Safin 1,3,4,\***


**Abstract:** In this work we report solvatochromic and luminescent properties of ethyl *N*-salicylideneglycinate (**1**), ethyl *N*-(5-methoxysalicylidene)glycinate (**2**), ethyl *N*-(5-bromosalicylidene)glycinate (**3**), and ethyl *N*-(5-nitrosalicylidene)glycinate (**4**) dyes. **1**–**4** correspond to a class of *N*-salicylidene aniline derivatives, whose photophysical properties are dictated by the intramolecular proton transfer between the OH-function and the imine N-atom, affording tautomerization between the enol-imine and keto-enamine forms. Photophysical properties of **1**–**4** were studied in different pure non-polar and (a)protic polar solvents as well as upon gradual addition of NEt3, NaOH, and CH3SO3H. The DFT calculations were performed to verify the structures of **1**–**4** as well as their electronic and optical properties.

**Keywords:** Schiff base; *N*-salicylidene aniline derivative; photophysical properties; solvatochromism; Hirshfeld surface analysis; DFT
