Structure-Property Relationship in Selected Naphtho- and Anthra-Quinone Derivatives on the Basis of Density Functional Theory and Car–Parrinello Molecular Dynamics

Beata Kizior,Jarosław J Panek,Aneta Jezierska,Bartłomiej M Szyja

doi:10.3390/sym13040564

Abstract

Intra- and inter-molecular interactions were studied in 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone and 1,4-dihydroxy-anthraquinone to shed more light on the molecular assembly phenomena. The electronic ground and excited states features of the compounds were investigated to find structure-property dependencies. The theoretical study was carried out on the basis of Density Functional Theory (DFT), its Time-Dependent (TD-DFT) extension, and using Car–Parrinello Molecular Dynamics (CPMD). In order to show how the environmental effects modulate the physico-chemical properties, the simulations were performed in vacuo, with the solvent reaction field (Polarizable Continuum Model (PCM) and water as a solvent) and crystalline phase. The intramolecular hydrogen bonds and the bridged proton dynamics were analyzed in detail. The aromatic rings and electronic structure changes were estimated using the Harmonic Oscillator Model of Aromaticity (HOMA) and Atoms in Molecules (AIM) theory. The Symmetry-Adapted Perturbation Theory (SAPT) was employed for interaction energy decomposition in the studied dimers and trimers. It was found that the presence of a polar solvent decreased the energy barrier for the bridged proton transfer. However, it did not significantly affect the aromaticity and electronic structure. The SAPT results showed that the mutual polarization of the monomers in the dimer was weak and that the dispersion was responsible for most of the intermolecular attraction. The intermolecular hydrogen bonds seem to be much weaker than the intramolecular bridges. The TD-DFT results confirmed that the electronic excitations do not play any significant role in the intramolecular proton transfer. The CPMD results indicated that the protons are very labile in the hydrogen bridges. Short proton transfer and proton-sharing events were observed, and a correlation between them in the twin bridges was noticed, especially for the first investigated compound.

Highlights

Naphtho- and anthra-quinone are parent compounds for 2,3-dichloro-5,8-dihydroxy1,4-naphthoquinone 1 [1] and 1,4-dihydroxy-anthraquinone 2 [2], which are the objects of the current study; see Figure 1
They are interesting classes of compounds from the materials science point of view. Their derivatives have been mentioned as, e.g., potential electrode-active material candidates in an acidic aqueous electrolyte [14]. They are able to improve the performance of flow batteries [15], and long-life lithium-organic batteries were developed based on the core structure of naphthoquinone [16]
The geometry optimization was performed in vacuo and with the solvent reaction field reproduced by the Polarizable Continuum Model (PCM) [23]

Summary

Introduction

Naphtho- and anthra-quinone are parent compounds for 2,3-dichloro-5,8-dihydroxy1,4-naphthoquinone 1 [1] and 1,4-dihydroxy-anthraquinone 2 [2], which are the objects of the current study; see Figure 1. Naphtho- and anthra-quinone occur in many natural products, possessing diverse biological activity, being building blocks of many dyes; see for example [3,4,5,6,7,8,9,10,11,12,13]. They are interesting classes of compounds from the materials science point of view. Their derivatives have been mentioned as, e.g., potential electrode-active material candidates in an acidic aqueous electrolyte [14]. The examples mentioned above show how important and interesting from diverse points of view naphtho- and anthra-quinone derivatives are

Methods

Results

Conclusion