The electronic properties of trimethylnaphthalenes as properties for the prediction of biodegradation rates: Ab initio and DFT study

• Published in: Chemosphere (Oxford) Vol. 88; no. 1; pp. 91 - 97
• Main Authors: OSTOJIC, Bojana D, DORDEVIC, Dragana S
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-06-2012; Elsevier
• Subjects: Ab initio; Applied sciences; Bacteria - enzymology; Biodegradation; Biodegradation, Environmental; Catalytic Domain; Density Functional Theory; Dipole moment; Electronics; Enzymes - chemistry; Enzymes - metabolism; Exact sciences and technology; Global environmental pollution; Isomerism; Models, Theoretical; Naphthalenes - metabolism; Polarizabilitiy; Pollution; Protein Binding; Trimethylnaphthalenes; Biodegradation; Ab initio; Trimethylnaphthalenes; Polarizabilitiy; Dipole moment; Density Functional Theory; Hydrocarbon; Polarizability; Pollutant behavior; Ab initio method; Polycyclic aromatic compound; Mutagen; Naphthalene derivatives; Persistent organic pollutant; Carcinogen; Pollution; Electronic structure; Density functional method; Environment; Property structure relationship; Organic compounds
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2012.02.071

► Electronic properties of trimethynaphthalenes (TMNs) and biodegradation by bacteria. ► Ab initio and DFT methods are employed. ► Ionization potentials and electron affinities of TMNs are almost constant. ► TMN-enzyme binding affinity is controlled by intermolecular interactions. ► Obtained polarizabilities can be used as predictors of biodegradation rates of TMNs.
There is little information on trimethylnaphthalenes (TMNs) which are constituents of diesel fuel and bitumen emissions. In this study, a theoretical investigation of the electronic properties of all trimethylnaphthalene (TMN) isomers and their relation to biodegradation are presented. Equilibrium geometries, ionization potentials (IPs), electron affinities (EAs), dipole moments and electronic dipole polarizabilities of TMN isomers calculated by ab initio and Density Functional Theory (DFT) methods are reported. Polarizability and dipole moment computations have been performed in gas and in water solution using the polarizable continuum model (PCM). The results obtained show that the IP value varies little along the series of isomers while averaged static dipole polarizabilities (〈α〉) increase on passing from α,α,α-TMN to β,β,β-TMN isomers. This indicates that the binding affinity between TMNs and active site of bacterial enzymes is mainly determined by dispersive and inductive effects. Therefore, the computed polarizability values of TMNs can be used as predictors of the rates of biodegradation of TMNs.