Synthesis, Structural Characterization and Theoretical NLO Activity of N-(4-Acetyl-5-(4-(Nitro) Phenyl)-4,5-Dihydro-1,3,4-Thiadiazol-2-yl)-N-Phenyl Acetamide

Abstract

The special properties of organic compounds are due to the polyvalence of the carbon atom. In this research, the organic single crystal of N-(4-acetyl −5-(4-(nitro) phenyl) −4,5-dihydro-1,3,4-thiadiazol-2-yl) -N-phenylacetamide (NTDZ) was successfully synthesized and crystallized in isopropanol by using slow evaporation solution growth method. FT-IR, ¹H and ¹³C NMR spectroscopic techniques were used to characterize the presence of various functional groups in the NTDZ molecular structure. Single crystal X-ray data have been collected and used for the structural determination of NTDZ. The title crystal crystallized in the monoclinic space group P21/c, according to X-ray analysis. Besides, quantum chemical studies were carried out using the density functional theory calculation method. The theoretical and experimental geometrical parameters were compared indicating a good accordance between them. Moreover, surface shapes were displayed using 3D-Hirshfeld surface analysis, and 2D-fingerprint graphs were used to quantify the contributions of C–H…O and C–H…N intermolecular interactions. Furthermore, the vibration spectrum of the NTDZ is calculated and compared with that obtained by FT-IR spectroscopy, and the predicted vibration assignments are made according to the potential energy distribution (PED). The chemical shifts of ¹H and ¹³C-NMR were calculated using the GIAO approximation and compared to experimental values. Using the TD-DFT method, the theoretical UV-Vis absorption spectrum was calculated in chloroform solvent to obtain the most important electronic transitions. Frontier molecular orbitals (HOMO and LUMO) indicate the charge transfer within the molecule. The global chemical reactivity descriptors (GCRD) were calculated. In addition, the MEP was also computed showing the functional groups responsible for building interactions with other molecules. Finally, the nonlinear optical behavior was investigated by the determination of the dipole moment (μ), the polarizability (α), and the first and second hyperpolarizabilities using the same level of theory. All of these findings suggest that the NTDZ crystal may be a viable candidate for NLO applications.

Highlights

• New 1,3,4-thiadiazol derivative was synthesized.

• X-ray geometry was determined and confirmed by theoretical calculation.

• Electronic behavior was investigated by DFT and TD-DFT.

• NLO properties of the compound were also computed.

Keywords:

• Thiadiazole
• DFT
• FT-IR
• NMR
• TD-DFT
• PED
• hyperpolarizability

Acknowledgements

The authors gratefully acknowledge the financial support via PRFU project from The Algerian Ministry of Higher Education and Scientific Research, the Directorate General of Scientific Research and Technological Development (DGRSDT), and Abdelhamid Ibn Badis University of Mostaganem.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Crystallographic data for the structure reported in this article have been deposited with Cambridge Crystallographic Data Center, CCDC 2174458 Copies of this information may be obtained free of charge from the Director, CCDC, 12 Union Road, Cambridge, CBZ IEZ, UK. Facsimile (44) 01223 336 033, E-mail: [email protected] or http//www.ccdc.com.ac.uk/deposit.