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Substituted Diphenylamine

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https://www.readbyqxmd.com/read/29286648/substituted-diphenylamine-antioxidants-and-benzotriazole-uv-stabilizers-in-aquatic-organisms-in-the-great-lakes-of-north-america-terrestrial-exposure-and-biodilution
#1
Zhe Lu, Amila O De Silva, Daryl McGoldrick, Wenjia Zhou, Thomas E Peart, Cyril J Cook, Gerald Tetreault, Pamela A Martin, Shane Raymond de Solla
Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are industrial additives of emerging environmental concern. However, the bioaccumulation, biomagnification and spatial distribution of these contaminants in the Great Lakes of North America are unknown. The present study addresses these knowledge gaps by reporting SDPAs and BZT-UVs in herring gull (Larus argentatus) eggs, lake trout (Salvelinus namaycush) and their food web in the Great Lakes for the first time. Herring gull eggs showed much higher detection frequency and concentrations of target SDPAs and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol(UV328) than that of the whole body fish homogenate...
December 29, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29142212/dye-sensitized-solar-cells-based-on-a-push-pull-zinc-phthalocyanine-bearing-diphenylamine-donor-groups-computational-predictions-face-experimental-reality
#2
Riccardo Milan, Gurpreet Singh Selopal, Marco Cavazzini, Simonetta Orlandi, Rita Boaretto, Stefano Caramori, Isabella Concina, Gianluca Pozzi
Computational studies have suggested that the integration of secondary amine as donor groups in the structure of unsymmetrical zinc phthalocyanine (ZnPc) should have positive effects on photovoltaic performance, once the molecule is integrated as light harvester in dye sensitized solar cells (DSSCs). Aiming at obtaining experimental confirmation, we synthesized a peripherally substituted push-pull ZnPc bearing three electron donating diphenylamine substituents and a carboxylic acid anchoring group and integrated it as sensitizer in TiO2-based DSSCs...
November 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28885854/phenoxazine-a-privileged-scaffold-for-radical-trapping-antioxidants
#3
Luke A Farmer, Evan A Haidasz, Markus Griesser, Derek A Pratt
Diphenylamines are widely used to protect petroleum-derived products from autoxidation. Their efficacy as radical-trapping antioxidants (RTAs) relies on a balance of fast H-atom transfer kinetics and stability to one-electron oxidation by peroxidic species. Both H-atom transfer and one-electron oxidation are enhanced by substitution with electron-donating substituents, such as the S-atom in phenothiazines, another important class of RTA. Herein we report the results of our investigations of the RTA activity of the structurally related, but essentially ignored, phenoxazines...
September 22, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28756218/occurrence-and-fate-of-substituted-diphenylamine-antioxidants-and-benzotriazole-uv-stabilizers-in-various-canadian-wastewater-treatment-processes
#4
Zhe Lu, Shirley Anne Smyth, Thomas E Peart, Amila O De Silva
Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are additives used in industrial and consumer products to prevent degradation or color change of materials, but their environmental fate and disposition are not well characterized. In this study, SDPAs and BZT-UVs were analyzed in 68 liquid and 39 solid samples collected from 9 wastewater treatment plants (WWTPs) in Canada to investigate the occurrence and fate of these contaminants. The median concentrations of ΣSDPAs and ΣBZT-UVs was 483 and 76...
November 1, 2017: Water Research
https://www.readbyqxmd.com/read/28601017/effect-of-substituted-phenylamine-antioxidants-on-three-life-stages-of-the-freshwater-mussel-lampsilis-siliquoidea
#5
R S Prosser, P L Gillis, E A M Holman, D Schissler, H Ikert, J Toito, E Gilroy, S Campbell, A J Bartlett, D Milani, J L Parrott, V K Balakrishnan
Substituted phenylamines (SPAs) are incorporated into a variety of consumer products (e.g., polymers, lubricants) in order to increase the lifespan of the products by acting as a primary antioxidant. Based on their physicochemical properties, if SPAs were to enter the aquatic environment, they would likely partition into sediment. No studies to date have investigated the effect of sediment-associated SPAs on aquatic organisms. The current study examined the effect of four SPAs (diphenylamine (DPA); N-phenyl-1-napthylamine (PNA); N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine (DPPDA); 4,4'-methylene-bis[N-sec-butylaniline] (MBA)) on three different life stages of the freshwater mussel, Lampsilis siliquoidea...
October 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28531846/synthesis-characterization-and-nonlinear-optical-nlo-properties-of-truxene-cored-diphenylamine-derivatives
#6
Fusheng Li, Baodong Zhao, Yu Chen, Yufei Zhang, Tao Wang, Song Xue
Three star-shaped compounds based on a truxene core (FS11, FS12 and FS13) were prepared. The truxene core is incorporating with asymmetric diphenylamines, including one phenyl of diphenylamine substituted by methoxy group and the other phenyl substituted by tolyl, fluorophenyl and phenylethynyl for FS11, FS12 and FS13, respectively. Their one-photon, two-photon absorption, geometric structures, electrochemical behavior and thermal properties were investigated. The absorption maxima of charge transfer band for FS11, FS12 and FS13 are 375nm, 373nm and 383nm, and the corresponding molar extinction coefficients of FS11, FS12 and FS13 is 79,950M(-1)cm(-1), 67,220M(-1)cm(-1) and 108,780M(-1)cm(-1)...
May 15, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28448906/variation-in-the-toxicity-of-sediment-associated-substituted-phenylamine-antioxidants-to-an-epibenthic-hyalella-azteca-and-endobenthic-tubifex-tubifex-invertebrate
#7
R S Prosser, A J Bartlett, D Milani, E A M Holman, H Ikert, D Schissler, J Toito, J L Parrott, P L Gillis, V K Balakrishnan
Substituted phenylamine antioxidants (SPAs) are produced in relatively high volumes and used in a range of applications (e.g., rubber, polyurethane); however, little is known about their toxicity to aquatic biota. Therefore, current study examined the effects of chronic exposure (28 d) to four sediment-associated SPAs on epibenthic (Hyalella azteca) and endobenthic (Tubifex tubifex) organisms. In addition, acute (96-h), water-only exposures were conducted with H. azteca. Mortality, growth and biomass production were assessed in juvenile H...
August 2017: Chemosphere
https://www.readbyqxmd.com/read/28418159/toxicity-of-sediment-associated-substituted-phenylamine-antioxidants-on-the-early-life-stages-of-pimephales-promelas-and-a-characterization-of-effects-on-freshwater-organisms
#8
Ryan S Prosser, Joanne L Parrott, Melissa Galicia, Kallie Shires, Cheryl Sullivan, John Toito, Adrienne J Bartlett, Danielle Milani, Patty L Gillis, Vimal K Balakrishnan
Substituted phenylamine antioxidants (SPAs) are high production volume chemicals that are incorporated into a variety of commercial products (e.g., polymers, dyes, lubricants). There are few data on chronic toxicity of SPAs to fish and no data on the toxicity of SPAs to the early life stages of fish. The physicochemical properties of SPAs would suggest that if they were to enter an aquatic ecosystem they would partition into sediment. Therefore, the present study focused on investigating the chronic effect of sediment-associated SPAs to the early life stages of the fathead minnow (Pimephales promelas)...
October 2017: Environmental Toxicology and Chemistry
https://www.readbyqxmd.com/read/27859737/meso-meso-linked-diarylamine-fused-porphyrin-dimers
#9
Norihito Fukui, Hideki Yorimitsu, Atsuhiro Osuka
A meso-meso-linked diphenylamine-fused porphyrin dimer and its methoxy-substituted analogue were synthesized from a meso-meso-linked porphyrin dimer by a reaction sequence involving Ir-catalyzed β-selective borylation, iodination, meso-chlorination, and SN Ar reactions with diarylamines followed by electron-transfer-mediated intramolecular double C-H/C-I coupling. While these dimers commonly display characteristic split Soret bands and small oxidation potentials, they produced different products upon oxidation with tris(4-bromophenyl)aminium hexachloroantimonate...
December 19, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27825981/structures-reveal-details-of-small-molecule-binding-to-cardiac-troponin
#10
REVIEW
Fangze Cai, Monica X Li, Sandra E Pineda-Sanabria, Shorena Gelozia, Steffen Lindert, Frederick West, Brian D Sykes, Peter M Hwang
In cardiac and skeletal muscle, the troponin complex turns muscle contraction on and off in a calcium-dependent manner. Many small molecules are known to bind to the troponin complex to modulate its calcium binding affinity, and this may be useful in a broad range of conditions in which striated muscle function is compromised, such as congestive heart failure. As a tool for developing drugs specific for the cardiac isoform of troponin, we have designed a chimeric construct (cChimera) consisting of the regulatory N-terminal domain of cardiac troponin C (cNTnC) fused to the switch region of cardiac troponin I (cTnI), mimicking the key binding event that turns on muscle contraction...
December 2016: Journal of Molecular and Cellular Cardiology
https://www.readbyqxmd.com/read/27791360/evidence-for-high-concentrations-and-maternal-transfer-of-substituted-diphenylamines-in-european-eels-analyzed-by-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry-and-gas-chromatography-fourier-transform-ion-cyclotron-resonance-mass-spectrometry
#11
Roxana Sühring, Xavier Ortiz, Miren Pena-Abaurrea, Karl J Jobst, Marko Freese, Jan-Dag Pohlmann, Lasse Marohn, Ralf Ebinghaus, Sean Backus, Reinhold Hanel, Eric J Reiner
Chemical pollution is hypothesized to be one of the factors driving the strong decline of the critically endangered European eel population. Specifically, the impact of contaminants on the quality of spawning eels and subsequent embryo survival and development has been discussed as crucial investigation point. However, so far, only very limited information on potential negative effects of contaminants on the reproduction of eels is available. Through the combination of nontargeted ultrahigh-resolution mass spectrometry and multidimensional gas chromatography, combined with more-conventional targeted analytical approaches and multimedia mass-balance modeling, compounds of particular relevance, and their maternal transfer in artificially matured European eels from the German river Ems have been identified...
December 6, 2016: Environmental Science & Technology
https://www.readbyqxmd.com/read/27662882/determination-of-substituted-diphenylamines-in-environmental-samples
#12
Zifeng Zhang, Ed Sverko, Shirley Anne Smyth, Christopher H Marvin
Owing to their stability at high temperature, low biodegradation, low water solubility, and low vapor pressure, substituted diphenylamines are used as antioxidants in rubber, foamed polymers, and as high-temperature functional fluids (e.g., lubricants, gear oils, and hydraulic fluids). There are few existing environmental measurements of these substances in any environmental medium. In this study, a method was developed for the determination of 10 substituted diphenylamines in wastewater, biosolids, and sediments using gas chromatography-tandem mass spectrometry (GC-MS/MS)...
November 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27477395/distribution-partitioning-and-bioaccumulation-of-substituted-diphenylamine-antioxidants-and-benzotriazole-uv-stabilizers-in-an-urban-creek-in-canada
#13
Zhe Lu, Amila O De Silva, Thomas E Peart, Cyril J Cook, Gerald R Tetreault, Mark R Servos, Derek C G Muir
Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs), previously under reported classes of organic contaminants, were determined in sediment, water, and freshwater biota in an urban creek in Canada. SDPAs and BZT-UVs were frequently detected in all matrices including upstream of the urban area in a rural agricultural/woodlot region, suggesting a ubiquitous presence and bioaccumulation of these emerging contaminants. Spatial comparisons were characterized by higher levels of SDPAs downstream compared with the upstream, implying a possible influence of the urban activities on the antioxidant contamination in the sampling area...
September 6, 2016: Environmental Science & Technology
https://www.readbyqxmd.com/read/27425756/simultaneous-determination-of-substituted-diphenylamine-antioxidants-and-benzotriazole-ultra-violet-stabilizers-in-blood-plasma-and-fish-homogenates-by-ultra-high-performance-liquid-chromatography-electrospray-tandem-mass-spectrometry
#14
Zhe Lu, Thomas E Peart, Cyril J Cook, Amila O De Silva
Analytical methods were developed for the determination of eight substituted diphenylamines (SDPAs) and six benzotriazole UV stabilizers (BZT-UVs) in blood plasma and fish homogenate matrices. Liquid-liquid extraction by methyl tert-butyl ether and denaturation by KOH following silica gel packed column clean-up was employed for blood plasma preparation. For the fish homogenate samples, ultrasonic assisted solvent extraction combined with automated gel permeation chromatography and silica gel packed column clean-up was used...
August 26, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/26862976/steric-hindrance-inhibits-excited-state-relaxation-and-lowers-the-extent-of-intramolecular-charge-transfer-in-two-photon-absorbing-dyes
#15
David J Stewart, Matthew J Dalton, Stephanie L Long, Ramamurthi Kannan, Zhenning Yu, Thomas M Cooper, Joy E Haley, Loon-Seng Tan
The two-photon absorbing dye AF240 [1, (7-benzothiazol-2-yl-9,9-diethylfluoren-2-yl)diphenylamine] is modified by adding bulky alkyl groups to the diphenylamino moiety. Three new compounds are synthesized which have ethyl groups in both ortho positions of each phenyl ring (2), t-butyl groups in one ortho position of each phenyl ring (3), and t-butyl groups in the para position of each phenyl ring (4). The dyes are examined in several aprotic solvents with varying polarity to observe the effects of the sterically hindering bulky groups on the ground and excited-state photophysical properties...
February 21, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/26088341/a-mechanofluorochromic-push-pull-small-molecule-with-aggregation-controlled-linear-and-nonlinear-optical-properties
#16
Yue Jiang, Denis Gindre, Magali Allain, Ping Liu, Clément Cabanetos, Jean Roncali
A small push-pull molecule involving a diphenylamine substituted by an oligo-oxyethylene chain is described. The compound exhibits aggregation-induced emission with solvent-dependent emission wavelength. Spin-cast deep-red amorphous films rapidly self-reorganize into colorless crystalline films which exhibit mechanofluorochromism and aggregation-induced second-harmonic generation.
August 5, 2015: Advanced Materials
https://www.readbyqxmd.com/read/25999616/practical-synthesis-of-aromatic-dithiocarbamates
#17
Panuwat Padungros, Alexander Wei
Oxidation-sensitive N,N-diaryl dithiocarbamates (DTCs) are synthesized in good yields by the generation of metal amide salts from N-benzoyl precursors, followed by addition of CS2. para-Substituted diphenylamines are prepared by electrophilic aromatic substitution of diphenylbenzamide and saponification. Deacylation of electron-rich species such as bis(p-dimethylaminophenyl)benzamide is challenging because of the oxidative sensitivity of the anionic intermediate but could be achieved in good yield by using n-BuLi to generate a hemiaminal adduct, prior to acidification...
2014: Synthetic Communications
https://www.readbyqxmd.com/read/25839082/maximizing-the-reactivity-of-phenolic-and-aminic-radical-trapping-antioxidants-just-add-nitrogen
#18
Luca Valgimigli, Derek A Pratt
Hydrocarbon autoxidation, the archetype free radical chain reaction, challenges the longevity of both living organisms and petroleum-derived products. The most important strategy in slowing this process is via the intervention of radical-trapping antioxidants (RTAs), which are abundant in nature and included as additives to almost every petroleum-derived product as well as several other commercial products. Accordingly, a longstanding objective of many academic and industrial scientists has been the design and development of novel RTAs that can outperform natural and industrial standards, such as α-tocopherol, the most biologically active form of vitamin E, and dialkylated diphenylamines, respectively...
April 21, 2015: Accounts of Chemical Research
https://www.readbyqxmd.com/read/25584392/formation-and-chlorination-of-carbazole-phenoxazine-and-phenazine
#19
Mohammednoor Altarawneh, Bogdan Z Dlugogorski
This contribution presents pathways for the formation of the three nitrogenated dioxin-like species, carbazole, phenoxazine, and phenazine via unimolecular rearrangements of diphenylamine (DPA) and its nitro substituents (NDPA). The latter represent major structural entities appearing in formulations of explosives and propellants. Intramolecular H transfer from the amine group to one of the two O atoms in the nitro group denotes the most accessible route in the unimolecular decomposition of NDPA. Further unimolecular rearrangements afford phenazine and carbazole...
February 17, 2015: Environmental Science & Technology
https://www.readbyqxmd.com/read/25447552/stim1-phosphorylation-triggered-by-epidermal-growth-factor-mediates-cell-migration
#20
Vanessa Casas-Rua, Patricia Tomas-Martin, Aida M Lopez-Guerrero, Ignacio S Alvarez, Eulalia Pozo-Guisado, Francisco Javier Martin-Romero
STIM1 is a key regulator of store-operated calcium entry (SOCE), and therefore a mediator of Ca²⁺ entry-dependent cellular events. Phosphorylation of STIM1 at ERK1/2 target sites has been described as enhancing STIM1 activation during intracellular Ca²⁺ emptying triggered by the inhibition of the sarco(endo)plasmic Ca²⁺ -ATPase with thapsigargin. However, no physiological function is known for this specific phosphorylation. The present study examined the role of STIM1 phosphorylation in cell signaling triggered by EGF...
January 2015: Biochimica et Biophysica Acta
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