Density Functional Theoretical Study of Mono-Nitrated Fluoranthenes

Abstract

The molecules 1-, 2-, 3-, 7-, and 8-nitrofluoranthenes are well-known mutagens and carcinogens. These environmental pollutants are emitted into the atmosphere via anthropogenic activities including diesel combustion emissions, residential home heating and reactions of nitrogen oxide (NO x ) gases with fluoranthene. The differential mutagenic potency between nitrated fluoranthenes has been proposed to emanate from the orientation of the nitro group relative to the aromatic plane. To establish the validity of the structure-function correlations requires specific crystal structures, which are unavailable. Fortunately, electronic structure calculations can be done. In this report, the structures of fluoranthene and its mono nitrated derivatives were investigated with the density functional theoretical theory at B3LYP/6-311+G** level. The structure-function correlations were examined by comparing reported mutagenicity data with calculated bond lengths, angles and dihedral angles. The relationships between the calculated structures and the reported mutagenicity in the chemical literature are discussed.

Structure–mutagenicity relationships and energies of 1-, and 2-nitrotriphenylenes

“…Other studies for fluoranthene and benzo[a]pyrene [27,28] have shown B3LYP/6-311 + G** reliable for predicting structural data. For nitrated PAHs, gas-phase calculations for nitrobenzene, and 6-nitrobenzo[a]pyrene with the B3LYP/6-311 + G** level [27,28] predicted structural data in good agreement with neutron and X-ray diffraction data.…”

“…doi:10.1016/j.theochem.2008.12.009 mutagenic potency than the non-planar nitro-PAH [5], and the nitro group orientation relative to the aromatic moiety was correlated to the observed mutagenicity. Such proposals have been a subject of investigation recently by others and our group [5,28,29]. A synergy between experiment and theory is thus proving useful in predicting structure in nitro-PAHs.…”

“…1B) determined from neutron and electron diffraction were previously compared with calculation at the B3LYP/6-311 + G** level [28] and is here used as a calibration test compound for mono nitrotriphenylenes. Results for nitrobenzene were found to be in good agreement with experimental data [27,[41][42][43][44][45].…”

“…The standard 6-311 + G** basis set was used for the geometric optimization. The DFT methods, especially the B3LYP hybrid DFT method, have been shown to reproduce reliable geometries [27][28][29], and require less time and computer resources [33]. Ground-state optimized geometries of the molecules were calculated without any geometrical restriction, except those enforced by symmetry.…”

Theoretical study on atmospheric reactions of fluoranthene and pyrene with N2O5/NO3/NO2

“…Considering that the reaction barriers of H-abstraction processes are significantly higher than those of NO 3 Figure 1. Labeled numbers in the structures of fluoranthene (FL) and pyrene (PY), followed by Onchoke [43]. For the addition of NO 3 , seven different reaction sites on FL and three different reaction sites on PY were revealed.…”