I would really appreciate some help regarding enzymes as chemistry isn't my background. I want to use naphthalene dioxygenase a hypothetical biocatalyst, if I use the enzyme to degrade any polycyclic aromatic hydrocarbon are there any useful products I can get ? I know that NDO has a use for breaking down pollutants but was hoping I could theoretically utilise a product even if not completely viable. Are any cis Dihydrodiols useful ? In any industry
Thank you !! (I have also posted to r/biochemistry)
Hi all, i've been working with a mushroom extract producer and he told me they only use hot water extraction because that way no polycyclic aromatic hydrocarbons would be produced. So i tried to learn how ethanol extractions would produce PAHs and came across a study that showed how mushrooms would remediate PAHs from polluted soil. This means the ethanol extraction could also extract those PAHs. Since i am a big fan of double extraction i wanted to know what you guys think of this. I am trying to get a good supplier of Chaga extract.
Pleas can you help me on understanding the naming of PAHs?? IUPAC system. I searched on the internet and I couldn’t find a good explanation:(
Cationic BN‐embedded polycyclic aromatic hydrocarbons ( BN‐PAH + s) were synthesized from a nitrogen‐containing macrocycle via pyridine‐directed tandem C–H borylation . Incorporating BN into PAH + resulted in a remarkable hypsochromic shift due to an increase in the LUMO energy and the symmetry changes of the HOMO and LUMO. Electrophilic substitution or anion exchange of BN‐PAH + possessing tetrabromoborate as a counter anion ( BN + [BBr 4 – ] ) afforded air‐stable BN‐ PAH/PAH + s. Of these, BN + [TfO – ] allowed reversible two‐electron reduction and the formation of two‐dimensional brickwork‐type π‐electronic ion pair with 1,2,3,4,5‐pentacyanocyclopentadienyl anion, demonstrating the potential application of BN‐PAH + as electronic materials.
https://ift.tt/3lAZKac
Three‐dimensional covalent organic frameworks (3D COFs) have been obtained from distorted polycyclic aromatic hydrocarbon nodes. Interframework π‐stacking enables charge transport properties that are not expected for 3D COFs.
Abstract
Three‐dimensional covalent organic frameworks (3D COFs) with a pcu topology have been obtained from distorted polycyclic aromatic hydrocarbons acting as triangular antiprismatic (D3d ) nodes. Such 3D COFs are six‐fold interpenetrated as the result of interframework π‐stacking, which enable charge transport properties that are not expected for 3D COFs.
https://ift.tt/3rZYTSR
Hydrogen plays multiple important roles in the on‐surface synthesis of carbon‐based materials. Here, the interactions between surface‐adsorbed polycyclic aromatic hydrocarbons (PAHs) and hydrogen are explored here by combining on‐surface H→D isotope exchange chemistry with in situ time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). It is shown that PAHs at hot surfaces continuously exchange hydrogen atoms.
Abstract
Hydrogen plays important roles in the on‐surface synthesis of carbon‐based materials in ultra‐high vacuum. The complex interplay between hydrogen and surface‐adsorbed polycyclic aromatic hydrocarbons (PAHs) is tracked by in situ time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) combined with isotope labeling. In situ deuterium labeling of prototypical PAHs, coronene (CR) and 7‐armchair graphene nanoribbons (GNRs), on Au(111) is achieved by annealing either in D2 gas or in the vapor of perdeuterio‐acenaphthene. By following the mass spectra of in situ deuterated CR mixed with hydrogen‐CR, it is demonstrated that PAHs adsorbed at hot Au(111) surfaces continuously exchange hydrogen atoms. Also, D2 present during the Ullmann coupling step leads to incorporation of deuterium and to shorter GNRs.
https://ift.tt/3qkWhh7
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c13298
Cheng Zeng, Bohan Wang, Huanhuan Zhang, Mingxiao Sun, Liangbin Huang, Yanwei Gu, Zijie Qiu, Klaus Müllen, Cheng Gu, and Yuguang Ma
https://ift.tt/2MOXBL2
A cobalt‐promoted electrochemical 1,2‐diarylation of alkenes with electron‐rich aromatic hydrocarbons via direct dual C‐H functionalizations is described, which employs a radical relay strategy to produce polyaryl‐functionalized alkanes. Simply by using graphite rod cathode instead of platinum plate cathode, chemoselectivity of this radical relay strategy is shifted to the dehydrogenative [2+2+2] cycloaddition via 1,2‐diarylation, annulation and dehydrogenation cascades leading to complex 11,12‐dihydroindolo[2,3‐a]carbazoles. Mechanistical studies indicate that a key step for the radical relay processes is transformations of the aromatic hydrocarbons to the aryl sp2‐hybridized carbon‐centered radicals via deprotonation of the corresponding aryl radical cation intermediates with bases.
https://ift.tt/3kwKnOR
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c07689
https://ift.tt/3iX040E
Simple synthetic routes for heteroatom‐containing polycyclic aromatic hydrocarbons (H‐PAHs) with alkyl and aryl substitution were demonstrated. Three H‐PAHs including heteroatom containing rubicenes (H‐rubicenes), angular‐benzothiophenes (ABTs), and indenothiophene (IDTs) were successfully synthesized through two key steps including polysubstituted olefins formation and cyclization. Specifically, ABT and H‐rubicenes were comprehensively investigated by single‐crystal X‐ray diffraction, NMR, UV‐vis absorption, cyclic voltammetry, transient absorption and single crystal OFET measurements.
https://ift.tt/35KdFTY
Novel organic lasers were fashioned from large, aggregation‐free polycyclic aromatic hydrocarbons (PAHs). Several new perylene‐based PAHs were prepared that show perylene‐like electronic properties with moderate fluorescence quantum yields. Two of them show amplified spontaneous emission, and solution‐processed distributed feedback lasers were successfully fabricated.
Abstract
Perylene‐fused, aggregation‐free polycyclic aromatic hydrocarbons with partial zigzag periphery (ZY‐01 , ZY‐02 , and ZY‐03 ) were synthesized. X‐ray crystallographic analysis reveals that there is no intermolecular π–π stacking in any of the three molecules, and as a result, they show moderate‐to‐high photoluminescence quantum yield in both solution and in the solid state. They also display the characteristic absorption and emission spectra of perylene dyes. ZY‐01 and ZY‐02 with a nearly planar π‐conjugated skeleton exhibit amplified spontaneous emission (ASE) when dispersed in polystyrene thin films. Solution‐processed distributed feedback lasers have been fabricated using ZY‐01 and ZY‐02 as active gain materials, both showing narrow emission linewidth (ZY‐03 did not show ASE and lasing, presumably due to its highly twisted backbone, which facilitates nonradiative internal conversion and intersystem crossing.
https://ift.tt/2znp7sx
I am now learning about hydrocarbon on the internet, and I am searching for information about benzene, what I only know about it is that
- It is aromatic,
- There are delocalized electron moving freely on delocalized pi orbital of the ring
- Due to the aromatic property, it will be relatively more stable
Because there are really a lack of materials I will be grateful if anyone can teach me more properties about aromatic hydrocarbons that I should know
Yes what I know is really few lol
Sorry if this is a newbie question. To my knowledge, in nitrogen heterocycles the lone pair behaves mostly like the bonded hydrogen on a carbon. Benzene, C6H6, is aromatic, so it makes sense that pyridine C5H5N is aromatic as well. But how is pyrrole C4H4NH aromatic when it's analogue cyclopentadiene C5H6 is not? Wouldn't a divalent NH behave like a divalent CH2?
The best I can think is, the lone pair on the nitrogen serves as the extra 2 pi electrons needed for aromaticity, combining with the 4 pi electrons from the Cp double bonds to make the needed 4n+2 for aromaticity. But if that's the case, why does the lone pair join the pi bond system? It's not bonding to a carbon atom, or accepting a proton (like in pyridinium C5H5NH+), so what makes it part of the bonded electrons?
Thanks so much for helping in advance, this has been bugging me for a while and I haven't been able to figure it out.
Don′t come too close! Intermolecular carbocation–π interactions between cyclopentenyl cations and aromatics confined in zeolites were shown to cause spatial proximity between the two compounds using 2D solid‐state NMR spectroscopy. They play a critical role in the formation of naphtalene as a precursor to coke species responsible for catalyst deactivation in the conversion of methanol to hydrocarbons.
Abstract
The understanding of catalyst deactivation represents one of the major challenges for the methanol‐to‐hydrocarbon (MTH) reaction over acidic zeolites. Here we report the critical role of intermolecular π‐interactions in catalyst deactivation in the MTH reaction on zeolites H‐SSZ‐13 and H‐ZSM‐5. π‐interaction‐induced spatial proximities between cyclopentenyl cations and aromatics in the confined channels and/or cages of zeolites are revealed by two‐dimensional solid‐state NMR spectroscopy. The formation of naphtalene as a precursor to coke species is favored due to the reaction of aromatics with the nearby cyclopentenyl cations and correlates with both acid density and zeolite topology.
https://ift.tt/38xFJKf
Polycyclic aromatic hydrocarbons (PAHs) containing multiple pairs of BN units have been designed and successfully synthesized through electrophilic borylation processes. Delocalized BN double‐bond characteristics and π‐conjugation extension is observed in these PAH oligomers. The inner moieties of the oligomers are more active than the outer moieties.
Abstract
BN‐embedded oligomers with different pairs of BN units were synthesized by electrophilic borylation. Up to four pairs of BN units were incorporated in the large polycyclic aromatic hydrocarbons (PAHs). Their geometric, photophysical, electrochemical, and Lewis acidic properties were investigated by X‐ray crystallography, optical spectroscopy, and cyclic voltammetry. The B−N bonds show delocalized double‐bond characteristics and the conjugation can be extended through the trans‐orientated aromatic azaborine units. Calculations reveal the relatively lower aromaticity for the inner azaborine rings in the BN‐embedded PAH oligomers. The frontier orbitals of the longer oligomers are delocalized over the inner aromatic rings. Consequently, the inner moieties of the BN‐embedded PAH oligomers are more active than the outer parts. This is confirmed by a simple oxidation reaction, which has significant effects on the aromaticity and the intramolecular charge‐transfer interactions.
https://ift.tt/2V9BY9Q
Hello, microbiology student, I would really appreciate some help regarding enzymes. I want to use naphthalene dioxygenase a hypothetical biocatalyst, if I use the enzyme to degrade any polycyclic aromatic hydrocarbon are there any useful products I can get ? I know that NDO has a use for breaking down pollutants but was hoping I could theoretically utilise a product. Are any cis Dihydrodiols useful ? In any industry
Thank you !!
Cationic BN‐embedded polycyclic aromatic hydrocarbons (BN‐PAH+) were synthesized via pyridine‐directed tandem C−H borylation. Anion exchange gave a brickwork‐type p‐electronic ion pair with 1,2,3,4,5‐pentacyanocyclopentadienyl anion ([PCCp–]).
Abstract
Cationic BN‐embedded polycyclic aromatic hydrocarbons (BN‐PAH+s) were synthesized from a nitrogen‐containing macrocycle via pyridine‐directed tandem C−H borylation. Incorporating BN into PAH+ resulted in a remarkable hypsochromic shift due to an increase in the LUMO energy and the symmetry changes of the HOMO and LUMO. Electrophilic substitution or anion exchange of BN‐PAH+ possessing tetrabromoborate as a counter anion (BN+[BBr4−]) afforded air‐stable BN‐PAH/PAH+s. Of these, BN+[TfO−] allowed reversible two‐electron reduction and the formation of two‐dimensional brickwork‐type π‐electronic ion pair with 1,2,3,4,5‐pentacyanocyclopentadienyl anion, demonstrating the potential application of BN‐PAH+ as electronic materials.
https://ift.tt/3lAZKac
Cationic BN‐embedded polycyclic aromatic hydrocarbons ( BN‐PAH + s) were synthesized from a nitrogen‐containing macrocycle via pyridine‐directed tandem C–H borylation . Incorporating BN into PAH + resulted in a remarkable hypsochromic shift due to an increase in the LUMO energy and the symmetry changes of the HOMO and LUMO. Electrophilic substitution or anion exchange of BN‐PAH + possessing tetrabromoborate as a counter anion ( BN + [BBr 4 – ] ) afforded air‐stable BN‐ PAH/PAH + s. Of these, BN + [TfO – ] allowed reversible two‐electron reduction and the formation of two‐dimensional brickwork‐type π‐electronic ion pair with 1,2,3,4,5‐pentacyanocyclopentadienyl anion, demonstrating the potential application of BN‐PAH + as electronic materials.
https://ift.tt/3lAZKac
Perylene‐fused, aggregation‐free polycyclic aromatic hydrocarbons with partial zigzag periphery (ZY‐01, ZY‐02, and ZY‐03) were synthesized. X‐ray crystallographic analysis reveals that there is no intermolecular π‐π stacking in all three molecules, and as a result, they show moderate‐to‐high photoluminescence quantum yield in both solution and solid state. They also display characteristic absorption and emission spectra of perylene dyes. ZY‐01 and ZY‐02 with a nearly planar π‐conjugated skeleton exhibit amplified spontaneous emission (ASE) when dispersed in polystyrene thin films. All solution‐processed distributed feedback lasers have been fabricated using ZY‐01 and ZY‐02 as active gain materials, both showing narrow emission linewidth (
https://ift.tt/2znp7sx
