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

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 Egap 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.

Synthesis and Experimental Structure of a Multifunctional Catechol‐Azomethinebenzoic Acid, DFT/DMol3Calculations, and Molecular Docking with Hsp90

“…The same OÀ H⋯N hydrogen bond was observed in DHBA . DMSO, [21] confirming that this intramolecular hydrogen bond is important for the planarity.…”

“…The same planar trans configured molecular conformation was previously found in the crystal structure of the solvate DHBA . DMSO (DHBA = (E)-4-((2-hydroxy-3,5-diiodobenzylidene)amino)benzoic acid; DMSO = dimethyl sulfoxide), [21] and the 4-methoxybenzyl-2-dihydroxybenzalaldimine units of a recently reported Zn coordination polymer. [8] Intramolecular OÀ H⋯N and OÀ H⋯O hydrogen bonds stabilize the molecular structure (Figure 1, Table 2).…”

“…[8,12,[21][22][23][24][25] Some of them provide two carboxylic acid functions and vary in the location of the two phenolic OH group for building up hydrogen bonding networks. [8,9,12,14,21] The deprotonated function of such 2,3-dihydroxybenzaldehyde-4aminobenzoic acid derivatives was previously used for coordination of metals, [8,12] and contain the biologically important catechol (benzene-1,2-diol) unit. [26][27][28] Heat shock proteins (Hsp) are among the most abundant intracellular proteins.…”

“…including many examples of 2,3‐dihydroxybenzaldehyde derivatives [16–20] . When including additionally to the 2,3‐dihydroxybenzaldehyde, the 4‐aminobenzoic acid functionality, the total number of studies is far smaller [8,12,21–25] . Some of them provide two carboxylic acid functions and vary in the location of the two phenolic OH group for building up hydrogen bonding networks [8,9,12,14,21] .…”

Polymorphs of Substituted p-Toluenesulfonanilide: Synthesis, Single-Crystal Analysis, Hirshfeld Surface Exploration, and Theoretical Investigation

“…The overall interactions present in the single crystal can be fragmented in order to find the contribution of contacts in the crystal packing. − For that purpose, two-dimensional (2D) fingerprint plots are formed. Figure a,e,i shows the 2D plot of overall interactions in MSBT , MSBM , and DAYWUW , respectively.…”