5-Methyl-2-thiophenecarboxaldehyde: Experimental and TD/DFT study

The 5-Methyl-2-thiophenecarboxaldehyde (MTC) and its derivatives present a wide range of biological activities. In this regard a combined experimental and theoretical analysis for MTC and its derivatives can help to understand the electronic factors involved in the mode of action in biological systems. In the present work we used FT-IR and UV-vis techniques to investigate the spectroscopic properties of MTC. The conformational and vibrational analyses were theoretically explored using DFT calculation at DFT/B3LYP/6-311++G(d,p) level. A full electronic analysis of compound was performed using TD-DFT/B3LYP/6-311++G(d,p) calculations in gas phase and in ethanol solvent with the CPCM model. The NLO parameters (β, γ and χ(3)) and FMO energies for MTC were calculated at the same level of theory. The relation between linear polarizability (α) and refractive index (n) were used to describe the polarization behavior of MTC in ethanol solvent. Our results indicate that MTC can be considered as a candidate to microscopic third−order NLO material.