Efficient Synthesis of Imine-Carboxylic Acid Functionalized Compounds: Single Crystal, Hirshfeld Surface and Quantum Chemical Exploration

Muhammad Nawaz Tahir; Akbar Ali; Muhammad Khalid; Muhammad Ashfaq; Mubashir Naveed; Shahzad Murtaza; Iqra Shafiq; Muhammad Adnan Asghar; Raha Orfali; Shagufta Perveen

doi:10.3390/molecules28072967

Efficient Synthesis of Imine-Carboxylic Acid Functionalized Compounds: Single Crystal, Hirshfeld Surface and Quantum Chemical Exploration

Molecules. 2023 Mar 27;28(7):2967. doi: 10.3390/molecules28072967.

Authors

Muhammad Nawaz Tahir¹, Akbar Ali², Muhammad Khalid^{3

4}, Muhammad Ashfaq¹, Mubashir Naveed¹, Shahzad Murtaza^{3

4}, Iqra Shafiq^{3

4}, Muhammad Adnan Asghar⁵, Raha Orfali⁶, Shagufta Perveen⁷

Affiliations

¹ Department of Physics, University of Sargodha, Sargodha 40100, Pakistan.
² Department of Chemistry, Government College University Faisalabad, Faisalabad 38000, Pakistan.
³ Institute of Chemistry, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan 64200, Pakistan.
⁴ Centre for Theoretical and Computational Research, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan 64200, Pakistan.
⁵ Department of Chemistry, Division of Science and Technology, University of Education, Lahore 54770, Pakistan.
⁶ Department of Pharmacognosy, College 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, MD 21251, USA.

Abstract

Two aminobenzoic acid based crystalline imines (HMBA and DHBA) were synthesized through a condensation reaction of 4-aminobenzoic acid and substituted benzaldehydes. Single-crystal X-ray diffraction was employed for the determination of structures of prepared Schiff bases. The stability of super molecular structures of both molecules was achieved by intramolecular H-bonding accompanied by strong, as well as comparatively weak, intermolecular attractive forces. The comparative analysis of the non-covalent forces in HMBA and DHBA was performed by Hirshfeld surface analysis and an interaction energy study between the molecular pairs. Along with the synthesis, quantum chemical calculations were also accomplished at M06/6-311G (d, p) functional of density functional theory (DFT). The frontier molecular orbitals (FMOs), molecular electrostatic potential (MEP), natural bond orbitals (NBOs), global reactivity parameters (GRPs) and natural population (NPA) analyses were also carried out. The findings of FMOs found that E_gap for HMBA was examined to be smaller (3.477 eV) than that of DHBA (3.7933 eV), which indicated a greater charge transference rate in HMBA. Further, the NBO analysis showed the efficient intramolecular charge transfer (ICT), as studied by Hirshfeld surface analysis.

Keywords: Hirshfeld surface analysis; NBO analysis; condensation reaction; density functional theory; single-crystal XRD.

Grants and funding

The authors extend their appreciation to the Researcher Supporting Project number (RSP2023R431), King Saud University, Riyadh, Saudi Arabia, for funding this research work.