Synthesis, characterization, surface analysis, optical activity and solvent effects on the electronic absorptions of Schiff base-functionalized amino thiophene derivatives: Experimental and TD-DFT investigations

New derivatives of 3,3′-di-((( E )-(5-substituted-thiophen-2-yl)methylene)amino)- N -methylpropylamines ( 3a,b ) were synthesized from the dehydration -methyl-diaminopropylamine and 2-thielylcarboxaldehyde derivatives; spectroscopically characterized by 1 H- 13 C-NMR, IR, LC-MS, UV-Vis elemental analysis. The nature electronic transitions SB compounds was investigated using Time-Dependent Density-Functional Theory (TD-DFT). Surface analysis influence solvent polarity on spectral properties examined established consequently. molecular electrostatic potential (MEP) revealed that two geometrical structures found to be quite similar in term distributions. presence different electrophilic nucleophilic sites located surfaces suggested stabilize via classical H-bond non-classical C-H…π interactions, addition interact with assorted molecules. On other hand, solvatochromism compound 3b a gradual shift red region through increase polarity, recording 12 nm bathochromic shift. solvation relationship between experimental λ max Gutmann's donicity numbers displayed sense positive linear behavior fluctuation, which ascribed week interaction molecules solute selected solvent. band gap energy 3a evaluated experimentally computationally. Using optical absorption spectra, value ‒ 3.801 eV estimated following Tauc approach, while 3.720 resulting TD-DFT simulation.