Issue 35, 2021

In acid-aminopyrimidine continuum: experimental and computational studies of furan tetracarboxylate-2-aminopyrimidinium salt

Abstract

Salts and cocrystals are the two important solid forms when a carboxylic acid crystallizes with an aminopyrimidine base such that the extent of proton transfer distinguishes between them. The ΔpKa value (pKa(base) − pKa(acid)) predicts whether the proton transfer will occur or not. However, the ΔpKa range, 0 < ΔpKa < 3, is elusive where the formation of cocrystal or salt cannot be predicted. The current study has been done to obtain a generalization in this elusive range with the Cambridge Structural Database (CSD). Based on the generalization, a novel salt (FTCA)(2-AP)+ of furantetracarboxylic acid (FTCA) with 2-aminopyrimidine (2-AP) is obtained. The structural confirmation was done by single-crystal X-ray diffraction (SCXRD). Density functional theory (DFT) calculations were performed at the IEF-PCM-B3LYP-D3/6-311G(d,p) level to optimize the geometrical coordinates of salt for frontier molecular orbitals (FMOs) and molecular electrostatic potential (MESP). The geometrical parameters of most of the atoms of the optimized salt structure were comparable with SCXRD data. Additionally, results of other computational methods such as ab initio (Hartree–Fock; HF and second-order-Møller–Plesset perturbation; MP2) and semi-empirical were also compared with experimental results of the salt. Quantum theory of atoms in molecules (QTAIM), reduced density gradient (RDG), and natural bond orbital (NBO) analyses were done to calculate the strength and nature of non-covalent interactions present in the salt. Furthermore, Hirshfeld surface analysis, interaction energy calculations, and total energy frameworks were performed for qualitative and quantitative estimations of strong and weak intermolecular interactions.

Graphical abstract: In acid-aminopyrimidine continuum: experimental and computational studies of furan tetracarboxylate-2-aminopyrimidinium salt

Supplementary files

Article information

Article type
Paper
Submitted
04 Mar 2021
Accepted
08 Jun 2021
First published
17 Jun 2021
This article is Open Access
Creative Commons BY license

RSC Adv., 2021,11, 21463-21474

In acid-aminopyrimidine continuum: experimental and computational studies of furan tetracarboxylate-2-aminopyrimidinium salt

U. Garg, Y. Azim and M. Alam, RSC Adv., 2021, 11, 21463 DOI: 10.1039/D1RA01714D

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements