Efficient Synthesis, Spectroscopic Characterization, and Nonlinear Optical Properties of Novel Salicylaldehyde-Based Thiosemicarbazones: Experimental and Theoretical Studies

Saifullah Bullo; Rifat Jawaria; Iqra Faiz; Iqra Shafiq; Muhammad Khalid; Muhammad Adnan Asghar; Rabia Baby; Raha Orfali; Shagufta Perveen

doi:10.1021/acsomega.3c00421

Efficient Synthesis, Spectroscopic Characterization, and Nonlinear Optical Properties of Novel Salicylaldehyde-Based Thiosemicarbazones: Experimental and Theoretical Studies

ACS Omega. 2023 Apr 7;8(15):13982-13992. doi: 10.1021/acsomega.3c00421. eCollection 2023 Apr 18.

Authors

Saifullah Bullo¹, Rifat Jawaria^{2

3}, Iqra Faiz^{2

3}, Iqra Shafiq^{2

3}, Muhammad Khalid^{2

3}, Muhammad Adnan Asghar⁴, Rabia Baby⁵, Raha Orfali⁶, Shagufta Perveen⁷

Affiliations

¹ Department of Human and Rehabilitation Sciences, Begum Nusrat Bhutto Women University, Sukkur Sindh 65170 Pakistan.
² Institute of Chemistry, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan 64200, Pakistan.
³ Center for Theoretical and Computational Research, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan 64200, Pakistan.
⁴ Department of Chemistry, Division of Science and Technology, University of Education Lahore, Punjab 54770, Pakistan.
⁵ Department of Education, Sukkur IBA University, zip code. Sukkur 65200, Pakistan.
⁶ Department of Pharmacognosy, Collage of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.
⁷ Department of Chemistry, School of Computer, Mathematical and Natural Sciences, Morgan State University, Baltimore, Maryland, 21251, United States.

Abstract

Currently, we reported the synthesis of six novel salicylaldehyde-based thiosemicarbazones (BHCT1-HBCT6) via condensation of salicylaldehyde with respective thiosemicarbazide. Through various spectroscopic methods, UV-visible and NMR, the chemical structures of BHCT1-HBCT6 compounds were determined. Along with synthesis, a computational study was also performed at the M06/6-31G(d,p) functional. Various analyses such as natural bond orbital (NBO) analysis, natural population analysis, frontier molecular orbital (FMO) analysis, and molecular electrostatic potential surfaces were carried out to understand the nonlinear optical (NLO) characteristics of the synthesized compounds. Additionally, a comparative study was carried out between DFT and experimental results (UV-vis study), and a good agreement was observed in the results. The energy gap calculated through FMOs was found to be in decreasing order as 4.505 (FHCT2) > 4.499 (HBCT6) > 4.497 (BHCT1) = 4.497(HMCT5) > 4.386 (CHCT3) > 4.241(AHCT4) in eV. The global reactivity parameters (GRPs) were attained through E _HOMO and E _LUMO, which described the stability and hardness of novel compounds. The NBO approach confirmed the charge delocalization and stability of the molecules. Among all the investigated compounds, a larger value (557.085 a.u.) of first hyperpolarizability (β_tot) was possessed by CHCT3. The NLO response (β_tot) of BHCT1-HBCT6 was found to be 9.145, 9.33, 13.33, 5.43, 5.68, and 10.13 a.u. times larger than that of the standard para-nitroaniline molecule. These findings ascertained the potential of entitled ligands as best NLO materials for a variety of applications in modern technology.