TITLE:
A Density Functional Theory (DFT) Investigation on the Structure and Spectroscopic Behavior of 2-Aminoterephthalic Acid and Its Sodium Salts
AUTHORS:
Mohammad A. Matin, Samiran Bhattacharjee, Md. Aftab Ali Shaikh, Tapas Debnath, Mohammed Abdul Aziz
KEYWORDS:
2-Aminoterephthalic Acid, Sodium 2-Aminoterephthalate, Trisodium 2-Aminoterephthalate, Tetrasodium 2-Aminoterephthalate, Density Functional Theory
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.10 No.2,
March
11,
2020
ABSTRACT: As a substitute for lithium ion batteries, Na
chemistry for ion battery systems is promising materials for energy storage
applications for the next generation.
Herein, the
structures, IR and UV-visible spectra of 2-aminoterephthalic acid (H2ATA), disodium 2-aminoterephthalate (Na2ATA),
trisodium 2-aminotere-phthalate (Na3ATA) and tetrasodium
2-aminoterephthalate (Na4ATA) have been studied using
density functional theory (DFT/B3LYP/6-311++G(d,p)).
The theoretical geometric parameters and FTIR results showed very
good agreement with the
experimental results. Different conformers of Na2ATA, Na3ATA
and Na4ATA showed that the binding energy per sodium in Na2ATA,
Na3ATA and Na4ATA is -694.94, -543.44 and -407.46 kJ/mol,
respectively. The Na3ATA and Na4ATA salts are higher in
energy (151.46 and 287.48 kJ/mol, respectively) than Na2ATA,
indicating the higher stability of the Na2ATA complex. The
calculated binding energy, enthalpy and Gibbs free energy of Na2ATA,
Na3ATA and Na4ATA revealed that the compounds are
thermodynamically stable. Natural bond orbital (NBO)
analysis of Na2ATA, Na3ATA and Na4ATA indicated that the major interaction occurs between
the lone pair electrons of the oxygen atom and anti-bonding orbitals of carbon
atoms of the two carboxylate ions. UV-visible spectrum of the free H2ATA and its sodium salts Na2ATA,
Na3ATA and Na4ATA were
performed using the time-dependent density functional theory (TD-DFT) method at
the level of B3LYP/6-311++G(d,p). The frontier molecular orbital energetic
parameters and global reactivity descriptors revealed that the Na4ATA
and Na3ATA complexes exhibited a higher band gap (ΔEgap)
and electronegativity (χeV) than Na2ATA.