Naphthalenes Research Articles

Characterization of size-resolved emissions of alkylated and nitrated polycyclic aromatic hydrocarbons (PAHs) from various combustion scenarios

In this study, we examined the size-resolved emissions of alkylated and nitrated polycyclic aromatic hydrocarbons (alkyl- and nitro-PAHs) from various combustion sources including residential solid fuels, cigarette smoking, domestic waste burning, and vehicular exhausts, which have been scarcely addressed. The estimated emission factors (eEFs) of these PAH derivatives were generally highest from the biomass burning sources. Very few nitro-PAHs were detected in cigarette smoking, cooking, and vehicle emission sources. Significant linear or non-linear relationships were observed between methylated PAHs and their parent compounds; whereas the relationships were weak for most nitro-PAHs, revealing the difference and similarity in their emission or accumulation formation mechanisms. The size distributions of individual methylated phenanthrenes (PHEs) and PHE were very similar in each source, but different between the sources. Generally, in sources with higher eEFs, these compounds were more tendentious to associate with the fine fractions. The intra-source size distributions of the methylated naphthalenes (NAPs) and NAP were different in some sources. The cooking and vehicle sources showed the lowest distributions of these PAHs derivatives in fine particles. The size fractionations of nitro-PAHs among the sources were very variable due to the low emissions, except for a few high molecular weight compounds showing more robust enrichment in the fine fractions. In addition to the size-resolved characterization, this work also highlights the need for understanding their formation and fractionation mechanisms.

Cover Feature: Ruthenium‐Catalyzed Cycloisomerization of 2‐Alkynylstyrenes via 1,2‐Carbon Migration That Leads to Substituted Naphthalenes (Chem. Eur. J. 45/2018)

Cover Feature: Ruthenium‐Catalyzed Cycloisomerization of 2‐Alkynylstyrenes via 1,2‐Carbon Migration That Leads to Substituted Naphthalenes (Chem. Eur. J. 45/2018)

Chromium-Catalyzed Dearomatization of Naphthalenes to Aldehydes

Chromium-Catalyzed Dearomatization of Naphthalenes to Aldehydes

ChemInform Abstract: Cobalt‐Catalyzed Formal [4 + 2] Cycloaddition of α,α′‐Dichloro‐ortho‐Xylenes with Alkynes.

AbstractThe Co‐catalyzed reaction of α,α′‐dichloro‐ortho‐xylenes with alkynes leads to 1,4‐dihydronaphthalenes and/or naphthalenes depending on the structure of starting compounds.

ChemInform Abstract: Synthesis of Functionalized Naphthalenes by Copper(I)‐Catalyzed Annulation Between 3‐(2‐Halobenzyl)pentane‐2,4‐diones and β‐Keto Esters, Malonates and Cyanoacetates.

ChemInform Abstract: Synthesis of Functionalized Naphthalenes by Copper(I)‐Catalyzed Annulation Between 3‐(2‐Halobenzyl)pentane‐2,4‐diones and β‐Keto Esters, Malonates and Cyanoacetates.

A Route to Highly Substituted Phenanthrenes and Naphthalenes

A Route to Highly Substituted Phenanthrenes and Naphthalenes

New Results on the Photoreactivity of 5-Fluoro-1,3-dimethyluracil with Methoxylated Naphthalenes

New Results on the Photoreactivity of 5-Fluoro-1,3-dimethyluracil with Methoxylated Naphthalenes

An Unusual Intramolecular P-P Cyclization of The P-C-P System in Phosphaphenalenes

An unusual P,P-disubstituted diphosphiranes was prepared and characterized by treatment of 1,8-bis[bis(di-alkylamino)phosphino]naphthalenes HCl followed by Me4NF.

Monitoring PAH contamination in the field (South west Iberian Peninsula): Biomonitoring using fluorescence spectrophotometry and physiological assessments in the shore crab Carcinus maenas (L.) (Crustacea: Decapoda)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants of the marine environment, arising predominantly from petrochemical contamination and pyrogenic sources. A biomarker of PAH exposure was employed in a field study (South West, Spain) in both captured (indigenous) and deployed (caged) shore crabs ( Carcinus maenas) in the chronic PAH-exposed Bays of Algeciras and Gibraltar (from associated harbour and boating activity) compared to a relatively ‘clean’ site (Cadiz). Metabolite fluorescence was attributed to the following key priority PAH groups; naphthalenes (NAPs), pyrenes (PYRs) and benzo[a]pyrenes (BAPs). Temporal variability was assessed using deployed populations over an eight week period. Petrogenic and pyrogenic PAH contamination (as an indicator of the PAH type) was demonstrated using a ratio between FF BAP + PYR/FF NAP. Physiological assessments from deployed crabs demonstrated both physiological and cellular alterations as shown by reduced heart rates (at rest) and increased cellular stress in crabs from the PAH contaminated sites.

Mass Transfer and Bioremediation of Naphthalene and Methyl Naphthalenes in Baffled and Bead Mill Bioreactors

AbstractMass transfer and bioremediation of naphthalene, 2‐methylnaphthalene and 1,5‐dimethylnaphthalene have been studied in a rotating bioreactor modified with the addition of baffles and beads. Mass transfer rates of these low solubility organic particles dissolving in water (based on the working volume of the bioreactor) were highest in the bioreactor that combined beads and baffles, with the overall mass transfer coefficient (KLa) reaching up to 25 h−1. Based on its capacity to hold the largest volume of polluted media, the simple baffled bioreactor was considered to be the optimum roller bioreactor design. Using Pseudomonas putida, the bioremediation rate of naphthalene reached 61 mg/l‐h in this vessel and using mixed substrates, the bioremediation rate of 2‐methylnaphthalene reached 30 mg/l‐h. The dissolution rates for hydrophobic particles into the culture media during the bioremediation process were up to four times higher compared to mass transfer rates into abiotic controls, which was likely due to the production of biosurfactants by P. putida.

The Structure of 1-(Arylthio)naphthalenes, Together with the Selenium and Oxygen Derivatives in Crystals and Solutions

Abstract

POLYCYCLIC AROMATIC HYDROCARBONS BIOACCUMULATION AND BIOTRANSFORMATION PRODUCTS IN TROUT EXPOSED THROUGH FOOD PELLETS

Polycyclic aromatic hydrocarbons (PAHs) were previously measured in whole small finfish (< 30 cm) or in the internal organs relative to the rest of tissues, as well as in muscle, liver, and gonads of larger finfish, collected offshore in the Northwest Atlantic. Alkylated naphthalenes (NA) were more abundant than phenanthrenes (PA), while fluoranthene (FL), pyrene (PY), and chrysene (CH) were also detected in some cases. Bioaccumulation pointed to uptake by respiration and, probably by a dietary contribution, especially for benthic species. Therefore, speckled trout were exposed to PA, FL, and PY through food and the parent PAH and their respective metabolites were analyzed. Trout maintained at 10°C were fed daily for 10 weeks with pellets spiked with 0.33–0.38 μg of each PAH per g fish. Muscle, internal organs, and bile of fish were analyzed by HPLC every 2 weeks, for up to 14 weeks. The concentration of PA was always higher than that of FL. No phase I or phase II metabolites were detected for either compound, even in the bile. Concentrations and total tissue burdens were higher in the internal organs than in the muscle for PA and FL. The highest levels of PA equivalent to 5 days' feeding were present in internal organs on week 10. Levels of PY were lower than levels of FL in internal organs and muscle. The amounts of PY-glucuronide in whole gall bladder bile were higher than amounts of PY in any whole compartment. PY-glucuronide was also detected in internal organs. Comparison will be made to a short-term exposure of winter flounder to 5 μg/g of the same three PAHs.

Synthesis of Functionalized Naphthalenes from Substituted 1-Methoxybenzocyclobutenes.

Synthesis of Functionalized Naphthalenes from Substituted 1-Methoxybenzocyclobutenes.

Syntheses of Calix[4]naphthalenes Derived from 1-Naphthol

Syntheses of Calix[4]naphthalenes Derived from 1-Naphthol

Lipid peroxidation and antioxidant enzyme activities in the rat testis after cigarette smoke inhalation or administration of polychlorinated biphenyls or polychlorinated naphthalenes.

Lipid peroxidation products and antioxidant enzyme activities were studied in the rat testis following exposures to cigarette smoke, polychlorinated biphenyls (PCBs), or polychlorinated naphthalenes (PCNs). Three hours after a single 1-hour period of smoke inhalation, the levels of fluorescent chromolipids and thiobarbituric acid-reactive species (TBARS) were markedly increased in the testis (+49%, P < 0.01, and +43%, P < 0.05, respectively). Twelve hours after daily smoking for 1 hour, for 1, 5, or 10 days, such an increase was not found. Activities of the antioxidant enzymes superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), glutathione transferase (GSH-Tr), or hexose monophosphate shunt (HMS) were not affected immediately, 3 hours, or 12 hours after a single smoking session. Twelve hours after smoking for 5 days, the activity of catalase was decreased (-16%, P < 0.05). Smoking exposures had no consistent effects on serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), or testosterone concentrations. Single i.p. injections of PCB or PCN mixtures resulted in decreases in testicular SOD activity 1 day after the exposures (-14%, P < 0.05, and -51%, P < 0.01, respectively). Catalase activity also decreased after both exposures (-30 to -42%, P < 0.05, at days 1-7 after PCB exposure, and -37 to -43%, P < 0.05, at days 3-7 after PCN exposure). Ninety days after the PCN exposure, activities of GSH-Px and GSH-Tr were decreased in the testis (-20%, P < 0.05, and -26%, P < 0.05, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Single atom, peri-bridged arenes: 1-alkylidene-1H-cyclobuta[de]naphthalenes and .DELTA.1,1-bi-1H-cyclobuta[de]naphthalene

Study is now reported of (1) improved methodology for preparing 1-alkylidene-1H-cyclobuta [de]-naphthalenes 2, (2) the detailed sttructure of crystalline 1-(diphenylmethylene)-1H-cyclobuta[de]naphthalene (2d), and (3) synthesis of Δ 1,1 -bi-1H-cyclobuta[de]naphthalene (3)

ChemInform Abstract: REACTIONS OF PHTHALANS WITH DIENOPHILES. I. SYNTHESIS OF NAPHTHALENES FROM PHTHALANS AND ACTIVATED ACETYLENES

AbstractPhthalane (II), die durch Alkylierung von Phthaliden (I) und Behandeln des entstehenden ionischen Produktes mit NaOEt dargestellt wurden, reagieren mit aktivierten Acetylenen (IV) zu den substituierten Naphthalinen (VIa), die durch IR‐ und NMR‐Daten charakterisiert wurden.

Novel polyhydronaphthalenic structures

Novel 1,7-dihydro- or 1,2,6,7-tetrahydronaphthalene derivatives were obtained from naphthalene through a polysilylation/oxidation process as well as 1,4,6,7-tetrakis(trimethylsily)naphthalene, a regiospecific precursor of 1,4,6,7-tetrafunctional naphthalenes.

Synthesis of some highly brominated naphthalenes

Synthesis of some highly brominated naphthalenes

Naphthalenes and biphenyls via a novel reaction of N,N-dimethylformamide dimethyl acetal

Naphthalenes and biphenyls via a novel reaction of N,N-dimethylformamide dimethyl acetal