scholarly journals Topological Analysis of PAHs using Irregularity based Indices

2021 ◽  
Vol 12 (3) ◽  
pp. 2970-2987
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Topological Analysis ◽  
Chemical Properties ◽  
Topological Descriptors ◽  
Graph Invariants ◽  
Chemical Structures ◽  
Potential Applications ◽  
Polycyclic Aromatic ◽  
Analytical Expressions

Topological descriptors are non-empirical graph invariants that characterize the structures of chemical molecules. The structural descriptors are vital components of QSAR/QSPR studies which form the basis for theoretical chemists to design and investigate new chemical structures. Irregularity indices are a class of topological descriptors that have been employed to study certain chemical properties of compounds. This article aims to compute analytical expressions of irregularity indices for three important classes of polycyclic aromatic hydrocarbons. The intriguing properties of these classes of compounds have several potential applications in wide-raging fields, which warrant a study of their properties from a structural perspective. Additionally, the 3D graphical representations of a few indices are presented, which will aid in analyzing the similarity of behavior among the indices.

scholarly journals Unpredicted Concentration-Dependent Sensory Properties of Pyrene-Containing NBN-Doped Polycyclic Aromatic Hydrocarbons

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 327
Author(s):  
Hang Xiao ◽  
Tao Li ◽  
Xiao-Li Sun ◽  
Wen-Ming Wan ◽  
Hongli Bao ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Aromatic Diamine ◽  
Fluoride Ion ◽  
Artificial Light ◽  
Dehydration Reaction ◽  
Turn On ◽  
Potential Applications ◽  
Polycyclic Aromatic ◽  
Nir Dye

Pyrene molecules containing NBN-doped polycyclic aromatic hydrocarbons (PAHs) have been synthesized by a simple and efficient intermolecular dehydration reaction between 1-pyrenylboronic acid and aromatic diamine. Pyrene-B (o-phenylenediamine) with a five-membered NBN ring and pyrene-B (1,8-diaminonaphthalene) with a six-membered NBN ring show differing luminescence. Pyrene-B (o-phenylenediamine) shows concentration-dependent luminescence and enhanced emission after grinding at solid state. Pyrene-B (1,8-diaminonaphthalene) exhibits a turn-on type luminescence upon fluoride ion addition at lower concentration, as well as concentration-dependent stability. Further potential applications of Pyrene-B (o-phenylenediamine) on artificial light-harvesting film were demonstrated by using commercial NiR dye as acceptor.

Partitioning of unsubstituted Polycyclic Aromatic Hydrocarbons between surface sediments and the water column in the Brisbane River Estuary

1990 ◽  
Vol 41 (4) ◽  
pp. 443 ◽  
Author(s):  
SI Kayal ◽  
DW Connell
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Water Column ◽  
Aromatic Hydrocarbons ◽  
Partition Coefficients ◽  
Laboratory Experiments ◽  
River Estuary ◽  
Chemical Properties ◽  
Linear Relationships ◽  
Physico Chemical ◽  
Polycyclic Aromatic

In all, 23 sediment samples and 8 water column samples from the Brisbane River estuary, Queensland, Australia, were analysed for polycyclic aromatic hydrocarbons (PAHs) in order to assess the field partitioning behaviour of these hydrocarbons. Twelve PAHs, ranging in molecular weight from naphthalene to benzo[a]pyrene, were identified and quantified. Their partition coefficients, indexed to sediment organic carbon and lipid content, were calculated after filtering to remove particulates and making a calculated adjustment for colloids, or organic matter, in the water phase. In logarithmic form, the partition coefficients were related to the physico-chemical properties of the compounds (Kow, Sw, RRT) by relationships having a parabolic shape rather than being linear. However, compounds with log Kow values of less than 5.5 gave linear relationships comparable to, but distinctly different from, those obtained from laboratory experiments. It is suggested that field conditions have distinctive differences from laboratory experiments that do not allow the direct translation of laboratory-based relationships to the natural aquatic environment.

scholarly journals Bioremediation of PAH-Contaminated Soils: Process Enhancement through Composting/Compost

2020 ◽  
Vol 10 (11) ◽  
pp. 3684 ◽  
Author(s):  
Tahseen Sayara ◽  
Antoni Sánchez
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Contaminated Soils ◽  
Low Cost ◽  
Polluted Soil ◽  
Ex Situ ◽  
Chemical Structures ◽  
Hydrophobic Chemical ◽  
Polycyclic Aromatic ◽  
The Stability

Bioremediation of contaminated soils has gained increasing interest in recent years as a low-cost and environmentally friendly technology to clean soils polluted with anthropogenic contaminants. However, some organic pollutants in soil have a low biodegradability or are not bioavailable, which hampers the use of bioremediation for their removal. This is the case of polycyclic aromatic hydrocarbons (PAHs), which normally are stable and hydrophobic chemical structures. In this review, several approaches for the decontamination of PAH-polluted soil are presented and discussed in detail. The use of compost as biostimulation- and bioaugmentation-coupled technologies are described in detail, and some parameters, such as the stability of compost, deserve special attention to obtain better results. Composting as an ex situ technology, with the use of some specific products like surfactants, is also discussed. In summary, the use of compost and composting are promising technologies (in all the approaches presented) for the bioremediation of PAH-contaminated soils.

scholarly journals Diversity-oriented synthesis of nanographenes enabled by dearomative annulative π-extension

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wataru Matsuoka ◽  
Hideto Ito ◽  
David Sarlah ◽  
Kenichiro Itami
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Template Synthesis ◽  
Science And Technology ◽  
Synthetic Methods ◽  
Structure Property ◽  
Oriented Growth ◽  
Diversity Oriented Synthesis ◽  
Potential Applications ◽  
Polycyclic Aromatic

AbstractNanographenes and polycyclic aromatic hydrocarbons (PAHs) are among the most important classes of compounds, with potential applications in nearly all areas of science and technology. While the theoretically possible number of nanographene structures is extraordinary, most of these molecules remain synthetically out of reach due to a lack of programmable and diversity-oriented synthetic methods, and their potentially huge structure-property diversity has not been fully exploited. Herein we report a diversity-oriented, growth-from-template synthesis of nanographenes enabled by iterative annulative π-extension (APEX) reactions from small PAH starting materials. The developed dearomative annulative π-extension (DAPEX) reaction enables π-elongation at the less-reactive M-regions of PAHs, and is successfully combined with complementary APEX reactions that occur at K- and bay-regions to access a variety of previously untapped nanographenes.

scholarly journals DHARWAD INDICES

2021 ◽  
Vol 10 (4) ◽  
pp. 17-21
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Graph Invariants ◽  
Polycyclic Aromatic

Recently, Gutman considered a class of novel graph invariants of which the Sombor index was defined. In this paper, we introduce the Dharwad index, reduced Dharwad index, -Dharwad index and their exponentials of a graph and compute exact formulas for polycyclic aromatic hydrocarbons and benzenoid systems.

Magnetic magnesium oxide composites for rapid removal of polycyclic aromatic hydrocarbons and cadmium ions from water

2020 ◽  
Vol 17 (7) ◽  
pp. 479
Author(s):  
Dongqin Tan ◽  
Jing Jin ◽  
Cuicui Guo ◽  
Dhanjai ◽  
Jiping Chen
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Three Dimensional ◽  
Precipitation Method ◽  
Precipitation Process ◽  
Cadmium Ions ◽  
Potential Applications ◽  
Equilibrium Data ◽  
Polycyclic Aromatic ◽  
Almost All

Environmental contextRemediation of wastewater containing polycyclic aromatic hydrocarbons and metals is essential to limit adverse effects on the environment and human health. Using a simple precipitation method, we prepared porous magnetic MgO hybrids for use as a material for removing pollutants from wastewater. The material showed excellent removal performance for 12 polycyclic aromatic hydrocarbons and cadmium ions, and thus has potential applications in wastewater treatment. AbstractHierarchical porous magnetic MgO hybrids (Fe3O4/MgO) are controllably synthesised based on a facile precipitation process. The resulting material displays a three-dimensional architecture with nest-like morphology, large surface area (135.2m2 g−1) and uniform mesochannels (5–35nm). The adsorption equilibrium data of target polycyclic aromatic hydrocarbons (PAHs) on Fe3O4/MgO sorbents are described by the Langmuir isotherm model. The composites show a strong tendency for the removal of PAHs owing to their porous structure that possesses an excellent affinity for PAHs. Under the optimal conditions, a removal of more than 70% is achieved for 12 PAHs. The materials also exhibit a good removal ability of cadmium (Cd2+) from water with fast adsorption (<5min) and high removal percentage (>80%). Moreover, the composites possess sufficient magnetism for separation. To demonstrate the performance of the sorbents, Fe3O4/MgO is exposed to aqueous samples spiked with low concentrations of PAHs and Cd2+. In almost all cases, the composites are superior to the commercially available sorbents as well as un-functionalised Fe3O4 nanoparticles. Therefore, this work provides a promising approach for the simultaneous removal of PAHs and Cd2+ from water using multifunctional MgO microspheres.

scholarly journals Exploration of the high-pressure behaviour of polycyclic aromatic hydrocarbons: naphthalene, phenanthrene and pyrene

2006 ◽  
Vol 62 (5) ◽  
pp. 826-842 ◽  
Author(s):  
Francesca P. A. Fabbiani ◽  
David R. Allan ◽  
Simon Parsons ◽  
Colin R. Pulham
Keyword(s):  
High Pressure ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Intermolecular Interactions ◽  
Aromatic Hydrocarbons ◽  
Pressure Range ◽  
Ambient Pressure ◽  
Topological Analysis ◽  
Direct Consequence ◽  
Structural Motif ◽  
Polycyclic Aromatic

The structural response of three members of the family of polycyclic aromatic hydrocarbons (PAHs) to high-pressure recrystallization from dichloromethane solutions is presented. Recrystallization of naphthalene in the 0.2–0.6 GPa pressure range does not result in the formation of a new polymorph. Furthermore, direct compression of a single crystal to 2.1 GPa does not result in a phase transition. A density decrease of 18.2% over the 0.0–2.1 GPa pressure range is observed and the principal effect of pressure is to `tighten' the herringbone structural motif and decrease the size of void regions. A new polymorph of pyrene, form III, has been crystallized at 0.3 and at 0.5 GPa. Structural investigation of this new polymorph by means of topological analysis and comparison of Hirshfeld surfaces and fingerprint plots shows that intermolecular interactions are substantially different from those found in the ambient-pressure structures, and do not fit a previously established packing model for PAHs. Similar discrepancies are found for the high-pressure polymorph of phenanthrene, which is here re-investigated in greater detail. The structures of these high-pressure polymorphs are dominated by π...π stacking with a limited contribution from C—H...π (peripheral) interactions. It is perhaps not surprising that high-pressure polymorphs deviate from a model that has been devised for ambient-pressure structures, and this may be a direct consequence of the ability of pressure to modify and combine intermolecular interactions in ways that are not usually found at ambient pressure. This is achieved by modifying the relative orientations of molecules and by encouraging the formation of denser structures in which molecules pack together more efficiently.

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