Podcasts about mtbe

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Best podcasts about mtbe

Latest podcast episodes about mtbe

Argus Media
Driving Discussions: MTBE Morsels

Argus Media

Play Episode Listen Later Jan 27, 2025 7:05


It's been a little more than half a year since Mexico swore in their new president. In this edition of Driving Discussions, senior methanol and MTBE reporter Steven McGinn talks with US Products Associate Editor Jason Metko about the events that have transpired since, and what can be expected in 2025 with a new American administration.

Year Of The Opposite - Travis Stoliker's Substack Podcast
Did You Know Your Home's Water Pipes Are Probably Plastic?

Year Of The Opposite - Travis Stoliker's Substack Podcast

Play Episode Listen Later Jan 24, 2025 5:19


Personal Note: I'm very sorry for the delay in publishing. We took a vacation to Florida to see the first launch of Blue Origins New Glenn rocket. Our 6 year old loves rockets and space —it was awesome! Although a bummer that all of the launches were at 1am. Quite a difficulty for a 6 year old and a wife that is 6 months pregnant. But they were troopers and really impressed me. If you can make it down to the space coast, I highly recommend it. My research project this week was about the microplastics we keep hearing about in our water bottles. As you read this one, please remember, absence of evidence isn't the same as evidence of harm. I do NOT want to worry anyone. But with all the talk about plastics in our water, I thought it was a good time to explore the plastic pipes that are in many of our houses. This is what I found out. Year Of The Opposite - Travis Stoliker's Substack is a reader-supported publication. To receive new posts and support my work, consider becoming a free or paid subscriber.We've all heard the concerns about microplastics in water bottles—especially when you leave them in a hot car. But here's a twist: the water lines running through many modern American homes are now made of plastic, too. It's called PEX (cross-linked polyethylene). And despite its widespread use, there are no large-scale, long-term human studies—or even randomized controlled trials—confirming whether PEX is 100% safe for our health.Before you panic, keep in mind that the absence of evidence isn't the same as evidence of harm. It just means research on PEX as a drinking water pathway hasn't fully caught up with its popularity. Here's the story so far:A Quick History of PEX• 1960s: PEX technology emerged, originally used for radiant floor heating in Europe.• 1980s–1990s: U.S. building codes gradually allowed its use for potable water.• 2000s: PEX gained traction as a flexible, freeze-resistant, and cost-effective alternative to copper or PVC.By now, it's the go-to solution for new builds and retrofits. Architects, plumbers, and homeowners alike praise its bendable nature, fewer connection points, and resistance to corrosion.What the Studies Say• Chemical Leaching: Laboratory tests have detected small amounts of volatile organic compounds (VOCs), like MTBE, that can leach out of PEX into standing water (particularly when new). Researchers found these levels drop with regular use and flushing.• Taste and Odor: Some people report a temporary plastic taste or odor from new PEX. Studies suggest it usually fades over time.• Microplastics?: Most available data focus on chemical migration, not tiny plastic particles. Current regulatory checks haven't flagged microplastics as a concern with PEX, but the research is still thin.Regulatory Green LightPEX is approved under NSF/ANSI 61, a standard that tests for any contaminants leaching into drinking water at levels above acceptable thresholds. It also meets ASTM specifications for durability and performance. Local codes rely on these certifications to ensure PEX is safe for installation.Here's the rub: certification is not the same as a 20-year population study. Instead, it involves lab-based testing against chemical limits. Many experts consider it sufficient. Others wonder what the unresearched long-term effects might be.Where This Stands• Widely Used, Light on Human Data: Millions of homes already have PEX, with very few reported issues. But we still lack large-scale, longitudinal health research tracking real-world outcomes over decades.• Absence of Evidence ≠ Evidence of Harm: No data says PEX is dangerous. No data says it's perfectly harmless. It's simply a technology that outpaced in-depth human trials.• Takeaway: If microplastics in water bottles worry you, it's worth asking what other plastic pathways your drinking water flows through—and whether you're comfortable with the relative unknowns.Want to try a new perspective this week? Rethink your assumptions about what “safe” really means. Just because something passes today's regulatory hurdles doesn't guarantee a well of peer-reviewed, long-term RCT data. Sometimes we accept what's proven to “work fine” without a definitive 40-year, double-blind experiment behind it.That's not necessarily bad—it's just where we stand right now. If you're feeling curious or concerned, do a little digging into how your home's water system is built. It might surprise you how many modern houses rely on plastic from the curb to the kitchen sink.But we also must keep in mind to always ask ourselves: “Compared to What?” Meaning, if we don't want our water to be stored in or transported in Plastic, are we safer if it is transported in metal? Lead? (Flint?) Buckets? Rivers? All of these sources have concerns and contaminants of their own. I guess this is all to say, it's complicated. Stay curious. Stay positive.-TravisFurther Reading1. Residential Tap Water Contamination Following the Use of Crosslinked Polyethylene (PEX) Potable Water Pipes (Whelton et al., 2014)2. Volatile Organic Components Migrating from Plastic Pipes (HDPE, PEX, and PVC) into Drinking Water (Skjevrak et al., 2003) Get full access to Year Of The Opposite - Travis Stoliker's Substack at www.yearoftheopposite.com/subscribe

Argus Media
Driving Discussions: MTBE Pricing and Presidential Politics

Argus Media

Play Episode Listen Later Mar 19, 2024 7:39


Find out about current US MTBE pricing, and how this summer's Mexican presidential election may play into the market, with senior methanol and MTBE reporter Steven McGinn, and host and associate editor of US products, Jason Metko.

Argus Media
Driving Discussions: High Times for MTBE

Argus Media

Play Episode Listen Later Sep 18, 2023 8:55


Senior Reporter for methanol and MTBE, Steven McGinn, and Argus' Blendstocks Reporter, Jason Metko, recap a very busy summer in the MTBE world, and how the market may finish the remainder of 2023. 

Argus Media
Driving Discussions: All about MTBE

Argus Media

Play Episode Listen Later Jun 22, 2023 16:07


Senior Reporter of methanol and MTBE Steven McGinn comes on the series, chatting all things MTBE, what the additive is, some recent price movements, and what to expect with the octane enhancer going forward.  

Argus Media
Chemical Conversations: MTBE Outlook

Argus Media

Play Episode Listen Later May 24, 2023 7:42


MTBE expert Roel Salazar talks to Lauren Williamson, VP, Product, about the outlook for MTBE, including:  Current trends and their effect on the MTBE market and its key drivers over the next 12-24 months  How Argus approaches its 5-year MTBE forecast  Where additional MTBE from a new Texas MTBE-ETBE unit might be absorbed and the challenges U.S. industry might face with that  Other key factors industry should monitor in 2023 and beyond  This podcast is delivered by Argus' MTBE experts using data and insight from the Argus MTBE Outlook.  Request a free trial or more information 

ICIS - chemical podcasts
Episode 985: MTBE Trade Flow between Northeast Asia and Europe stopped as 2023 started

ICIS - chemical podcasts

Play Episode Listen Later Apr 13, 2023 4:52


LONDON (ICIS)-- Northeast Asia's MTBE export to Europe grew largely in 2022, especially in Q2 and Q3. China remained the main global exporter in 2022, with around 20m tonnes production capacity. However, the first quarter of 2023 show a completely opposite picture where the market has not seen any new trade emerging between China and the Europe. Balanced European market in Q1 with good supply Overcapacity continues in China with export expectation Low discussion of exports from northeast Asia to the Europe for 2023

Environmental Law Monitor
Back to the Future, Part 2: Learning PFAS Lessons From the History of MTBE With Steven Cook

Environmental Law Monitor

Play Episode Listen Later Mar 7, 2023 24:43


In the second of a two-part episode of the Bracewell Environmental Law Monitor, host Daniel Pope continues the conversation with Bracewell partner Steven Cook about per- and polyfluoroalkyl substances (PFAS). They explore the unique challenges presented by the ubiquity of PFAS in society and how government and industry stakeholders can assess and respond to the long-term adverse consequences.

Environmental Law Monitor
Back to the Future, Part 1: Learning PFAS Lessons From the History of MTBE With Steven Cook

Environmental Law Monitor

Play Episode Listen Later Feb 21, 2023 31:59


In the first of a two-part episode of the Bracewell Environmental Law Monitor, host Daniel Pope talks with Bracewell partner Steven Cook, who served as deputy assistant administrator at the EPA's Office of Land and Emergency Management prior to joining the firm, about the ways that companies and agencies deal with per- and polyfluoroalkyl substances (PFAS) and a look back at the history of the methyl tert-butyl ether (MTBE) controversy and the lessons learned from that.

ICIS - chemical podcasts
Episode 932: China’s MTBE export market to remain active in 2023 amid oversupply exists

ICIS - chemical podcasts

Play Episode Listen Later Jan 12, 2023 3:07


In this podcast, ICIS analysts Candy Nie and Aviva Zhang look back on the methyl tertiary butyl ether (MTBE) market in 2022 and discuss the market outlook in 2023.

Argus Media
Chemical Conversations: MTBE Outlook

Argus Media

Play Episode Listen Later Sep 16, 2022 20:54


Jeff Eickholt, MTBE analyst, talks to leading MTBE expert Roel Salazar about the Argus MTBE Outlook: Market direction and underlying trends over the next 12 months Major supply and demand changes on the horizon Insights to help subscribers make better business decisions This podcast is delivered by Argus' MTBE experts using data and insight from the Argus MTBE Outlook. Get more information and request a free trial

ICIS - chemical podcasts
Episode 840: China’s MTBE exports to fall, with rising domestic demand

ICIS - chemical podcasts

Play Episode Listen Later Jul 27, 2022 3:15


ICIS - chemical podcasts
Episode 779: Europe methanol demand healthy for Q2, MTBE usage increases

ICIS - chemical podcasts

Play Episode Listen Later Apr 25, 2022 7:20


European methanol demand remains healthy with downstream applications performing well, and in some instances better than anticipated for Q2. Methyl tertiary butyl ether (MTBE) demand is strong ahead of the peak summer driving season leading to high expectations for Q3 2022. ICIS editors Eashani Chavda and Nazif Nazmul discuss current market dynamics and what's next for MTBE.

Argus Media
Chemical Conversations: MTBE Outlook

Argus Media

Play Episode Listen Later Mar 18, 2022 6:48


James Elliott talks to leading MTBE expert Roel Salazar, and lead analyst Cassidy Staggers, about the Argus MTBE Outlook: Market direction and underlying trends over the next 12 months Expansion projects and regulatory policies that could affect prices and trade flows Information or visuals with deep relevance to the market How we forecast 24 months ahead Insights to help subscribers make better business decisions This podcast is delivered by Argus' MTBE experts using data and insight from the Argus MTBE Outlook. Get more information and request a free trial

ICIS - chemical podcasts
Episode 672: European octane boosters during the summer of '21

ICIS - chemical podcasts

Play Episode Listen Later Aug 27, 2021 5:35


Nazif Nazmul, Europe editor for ethyl and methyl tert-butyl ethers (ETBE and MTBE) and biofuels discusses with Zubair Adam, Europe editor for toluene and mixed xylenes (MX) the impacts that gasoline demand had for these products during the peak summer period.

ICIS - chemical podcasts
Episode 672: European peak gasoline blending impacts on octane boosters '21

ICIS - chemical podcasts

Play Episode Listen Later Aug 26, 2021 5:35


Nazif Nazmul, Europe editor for ethyl and methyl tert-butyl ethers (ETBE and MTBE) and biofuels discusses with Zubair Adam, Europe editor for toluene and mixed xylenes (MX) the impacts that gasoline demand had for these products during the peak summer period.  

LALA SAID WHAT
Catching Up with Level Water CEO John

LALA SAID WHAT

Play Episode Listen Later Jul 8, 2021 13:29


OUR STORY CEO John R. Williamson Jr. takes us into Level Water. The New Orleans Native and Army-veteran has inspired an awakening in the Big Easy! He and his team are bringing you the water of the next generation. They are proud to present Level Ultra Purified Water+. LEVEL Water is a New Orleans based bottled water company providing a sustainable reliable brand of water that relates to this generation and it's ever growing health conscious lifestyles. The Company also uses its power in the best possible ways to help promote social, physical and mental change in the community. With every bottle purchased a donation is made to MSAADA Inc. to help fund local community programs. “Leveling Up” is not just a saying it's a lively hood. We encourage you to Level Up! We are excited to offer you the opportunity to increase your lifestyle through a superb quality of water, a water that has a pH balance of 9.0, a water with added trace minerals of calcium, magnesium and potassium, a water with superior taste, a water that hydrates your mind, body and spirit. A water that causes you to LEVEL UP! It's Not Just Any Water. 11 Stage Purification Process Added Ionic Trace Minerals Calcium, Magnesium, Potassium Superior Taste and Hydration Fluoride, Arsenic, Chlorine, MTBE, Chromium-6 & BPA Free pH 9.0+ --- Support this podcast: https://anchor.fm/laladatruth/support

ICIS - chemical podcasts
Episode 502: Europe MTBE demand recovery Q2 onwards, methanol price pressure continues

ICIS - chemical podcasts

Play Episode Listen Later Jan 7, 2021 11:51


ICIS editors Eashani Chavda and Nazif Nazmul discuss market fundamentals and expectations for European methyl tertiary butyl ether (MTBE) and methanol. With the winter driving season driving low demand for MTBE this month, demand is expected to improve by Q2 at the earliest.Meanwhile, supply shortages and healthy demand for Q1 is expected to drive a bullish methanol market.

Making The Black Entrepreneur Podcast
HNY, CH, IG, YT, & MTBE Feat. 8th Anderson

Making The Black Entrepreneur Podcast

Play Episode Listen Later Jan 1, 2021 11:42


"Momma we MADE it!"... Dreamers we leapt across the line to 2021! I am off recharging so I just dropped a mini-episode.  Wanna know more about our guest? Click the links below. Podcast Page Podcast IG & Eighth's IG

ICIS - chemical podcasts
Europe MTBE margins boosted by lower methanol prices

ICIS - chemical podcasts

Play Episode Listen Later Aug 24, 2020 9:59


LONDON (ICIS)--Following a U-shaped recovery from Q2, European methyl tertiary butyl ether (MTBE) margins have been lifted by lower methanol prices.European editors Eashani Chavda and Nazif Nazmul discuss the latest developments in these markets, and how higher ethanol costs have also fed into MTBE demand.

ICIS - chemical podcasts
Europe methanol demand lifted by recovery in downstream MTBE & biodiesel markets

ICIS - chemical podcasts

Play Episode Listen Later Jul 23, 2020 9:06


LONDON (ICIS)--European methanol demand remains lacklustre across a number of downstream markets however there has been increased consumption in gasoline blending applications such as methyl tertiary butyl ether (MTBE) and biodiesel.European editors Eashani Chavda and Nazif Nazmul discuss the relationship between these markets and progress of demand recovery since the pandemic spread in Europe over Q2.

More Than Dice
MTBE 09: Everything's OK in a three way (fight)

More Than Dice

Play Episode Listen Later Jun 23, 2019 133:06


MTBE 09: Everything's OK in a three way (fight) by More Than Dice

More Than Dice
MTBE 8: Welcome to the Secret War!

More Than Dice

Play Episode Listen Later May 30, 2019 119:11


MTBE 8: Welcome to the Secret War! by More Than Dice

More Than Dice
MTBE-05 Ninja Scientists and Science Cannons

More Than Dice

Play Episode Listen Later Mar 3, 2019 135:46


MTBE-05 Ninja Scientists and Science Cannons by More Than Dice

More Than Dice
MTBE - 03

More Than Dice

Play Episode Listen Later Dec 22, 2018 185:55


MTBE - 03 by More Than Dice

mtbe
More Than Dice
MTBE-02: Fanny Pack of Doom!

More Than Dice

Play Episode Listen Later Nov 28, 2018 147:27


MTBE-02: Fanny Pack of Doom! by More Than Dice

Meant To Be Eaten
#31 – The One Who Knows More About Japanese Things than Practically Anybody

Meant To Be Eaten

Play Episode Listen Later Sep 9, 2018 55:53


The late, LA Times critic, Jonathan Gold, so describes today’s MTBE guest. An author of 3 (soon to be 4) tomes on Japanese cooking, Nancy Hachisu is proof in the pudding that another, once-foreign culture, cuisine, food, and mannerisms, can be studied, learned, and embodied...sensitively, accurately, and holistically. Nancy and Coral discuss why Japanese cuisine enjoys higher prestige than others, in America, and why is it more often creatively appropriated, rather than mis-appropriated.

ICIS Americas Podcast
Strong MTBE, ETBE demand expected as LyondellBasell breaks ground on PO/TBA plant - ICIS Americas podcast 24 August 2018

ICIS Americas Podcast

Play Episode Listen Later Aug 23, 2018 4:16


News reporter David Haydon speaks with markets editor Steven McGinn on expected strong demand in the US methyl tertiary butyl ether (MTBE) market. Discussions include LyondellBasell's recent groundbreaking for its $2.4bn propylene oxide (PO)/tertiary butyl alcohol (TBA) project in Channelview, Texas. The TBA will be converted to MTBE and ethyl tertiary butyl ether (ETBE). MTBE was phased out of the US gasoline pool over a decade ago in favour of corn-based ethanol. However, international markets, such as Mexico, Latin America and China, remain a robust destination for the gasoline additive, and Lyondellbasell said it sees its high-octane fuels production as key to the growing market.

Meant To Be Eaten
#21 – You are What you Eat: The History of "Terroir"

Meant To Be Eaten

Play Episode Listen Later May 8, 2018 49:01


Kicking off MTBE’s 3rd season, is author and professor Thomas Parker. His most recent book, Tasting French Terroir: The History of an Idea, explores the origins and significance of the French concept of terroir. We also discuss his event series and blog, Subnature and Culinary Culture, which examined the history of foods that have been marginalized and re-appropriated by different cultures throughout history. Meant to Be Eaten is powered by Simplecast

Commodities Spotlight Podcast
Interview: Abdulrahman S. Al-Fageeh, SABIC

Commodities Spotlight Podcast

Play Episode Listen Later May 4, 2018 9:16


Abdulrahman S. Al-Fageeh, SABIC Executive Vice President - Petrochemicals, joins S&P Global Platts Editor Frank Zeng in this episode of the Platts Commodities Spotlight podcast, recorded at the ChinaPlas Conference 2018, to talk about company updates, the implications of the trade tension between...

us china polymer shale abdulrahman petrochemicals platts sabic us shale ethane s&p global mtbe petchems commodities spotlight
Meant To Be Eaten
#8 –The Price of Immigrant Foods in America

Meant To Be Eaten

Play Episode Listen Later Nov 7, 2017 45:47


Oft-quoted and well-loved by the MTBE team, Krishnendu Ray--NYU Food Studies Professor and author of two books on immigrant foods in America--joins us to talk about why searching out the most "authentic, ethnic" cuisines can be a problem, how social media has democratized food and why expensive Chinese is in our future food forecast. Meant to Be Eaten is powered by Simplecast

Commodities Spotlight Podcast
Could China tax on mixed aromatics imports alter EU gasoline blending economics?

Commodities Spotlight Podcast

Play Episode Listen Later May 5, 2017 6:03


Expectations are rife of an introduction of consumption taxes on mixed aromatics into China. But will this change the face of the European blending components market? Yuriko Kato, petrochemicals EMEA editor, explores this subject with the aromatics senior specialist, Sam Hashmi, and the gasoline...

Nourish Balance Thrive
Surviving in a Toxic World: Nonmetal Toxic Chemicals and Their Effects on Health

Nourish Balance Thrive

Play Episode Listen Later Sep 8, 2016 59:06


This podcast is the second part of a series. In the first part, Dr. Shaw and I talked about how to measure metabolism using organic acids. My initial test showed two major problems: yeast and clostridia overgrowth. It’s been about six months since I took probiotics and Raintree Formulas Amazon antifungals for two months and the retest shows some but not complete improvement. The primary focus of this interview is the new Great Plains test for organic (nonmetal) environmental toxicity, something that I think may be a problem for the people that work with us. I won’t know for sure until we collect some more data, as always I like to test myself before recommending others do the same, and my result turned out to be “one of the cleanest Dr. Shaw has ever seen.” The possible exception is a mild elevation of 2-Hydroxyisobutyric and other metabolites that indicate exposure to petrochemicals I suspect from riding my bike on the road. Download my full result About my guest William Shaw, Ph.D., is board certified in the fields of clinical chemistry and toxicology by the American Board of Clinical Chemistry. Before he founded The Great Plains Laboratory, Inc., he worked for the Centers for Disease Control and Prevention (CDC). Order an organic acids test with nonmetal chemicals profile Use the discount code TOX for $150 off. Here’s the outline of this interview with Dr William Shaw, Ph.D. 0:00:18    Previous interview. 0:03:25    HPHPA (3-(3-hydroxyphenyl)-3-hydroxypropionic acid). 0:03:55    D-Lactate free probiotic. 0:04:37    Vancomycin or Metronidazole. 0:05:03    Results, markers 33 and 34. 0:07:00    Arabinose. 0:07:24    Amazon A-F. 0:10:34    The Role of Oxalates in Autism and Chronic Disorders. 0:13:19    How to Protect Your Family from Environmental Toxicity with Dr. Julie Walsh on the Paleo Baby podcast. 0:13:37    AHS16 - Tim Gerstmar - Obesogens and Endocrine Disruptors. 0:16:44    Succinic dehydrogenase. 0:18:20    Tiglylglycine. 0:19:04    Kearns-Sayre syndrome. 0:20:40    2-Hydroxyisobutyric Acid, MTBE and ETBE. 0:43:12    Sauna + niacin flush. 0:50:18    discount code TOX. 0:57:54    GPL webinar archive. 0:58:08    GPL University upcoming events.

Commodities Spotlight Podcast
Interview: Stephen Bowers, Evonik, on the outlook for European MTBE, gasoline markets (part 1)

Commodities Spotlight Podcast

Play Episode Listen Later Jan 17, 2014


Platts petrochemicals editor, Antonios Panagiotopoulos talks to Stephen Bowers, Global Projects, Advanced Intermediates - Performance Intermediates, Evonik, on the challenges and risks facing the European MTBE and gasoline markets. We welcome any feedback or suggestions for topics. Contact us at...

BrainStuff
What is the problem with MTBE in gasoline?

BrainStuff

Play Episode Listen Later Jan 14, 2013 3:25


Some gasoline contains MTBE, or methyl tertiary butyl ether. Find out why MTBE is added to gasoline in the first place, and why it's no longer a popular additive, in this episode of BrainStuff. Learn more about your ad-choices at https://news.iheart.com/podcast-advertisers

Fakultät für Chemie und Pharmazie - Digitale Hochschulschriften der LMU - Teil 04/06

A broad range of organocopper intermediates in different aggregation states were characterized by electrospray ionization (ESI) mass spectrometry, which provided valuable information on these fluxional species. To complement the mass spectrometric data, electrical conductivity measurements and theoretical calculations were employed. Tetrahydrofuran (THF) solutions of CuCN/(RLi)m stoichiometry (m = 0.5, 0.8, 1.0, and 2.0 and R = Me, Et, nBu, sBu, tBu, Ph) were analyzed by ESI mass spectrometry, and organocuprate anions were detected for all cases. The composition of these species showed clear dependence on the amount of RLi used. Thus, while cyanide-free Lin–1CunR2n– anions completely predominated for CuCN/(RLi)2 solutions, cyanide-containing Lin–1CunRn(CN)n– complexes prevailed for CuCN/(RLi)m reagents with m ≤ 1. Ligand mixing studies on LiCuMe2•LiCN and LiCuR2•LiCN systems (R = Et, nBu, sBu, tBu, Ph) revealed fast exchange equilibria operating in solution. When THF was substituted for the less polar diethyl ether (Et2O), no major new species were observed. However, the proportion of higher nuclearity anions was consistently greater in the latter solvent than in the former. Further experiments with 2-methyltetrahydrofuran (MeTHF), cyclopentyl methyl ether (CPME) and methyl tert-butyl ether (MTBE) solutions confirmed the suggestion that higher aggregation states are favored by lower polarity solvents. Additional conductivity experiments indicated that contact ion pairs strongly predominate for solutions in Et2O, whereas the more polar THF gives rise to larger amounts of solvent-separated ion pairs. Following the detection of organocuprate ions, their gas- and condensed-phase reactions were investigated. Collision-induced dissociation (CID) experiments were used to study intrinsic reactivities in the gas phase. Higher aggregates were found to break apart into fragments of lower nuclearity, whereas monomeric species decomposed by beta-H elimination when possible. In some CID spectra, the presence of hydroxyl-containing signals led to the conclusion that a reaction with background water inside the mass spectrometer was taking place. This bimolecular reaction was then studied in detail for many different systems. The results indicate that lithium centers seem to be a necessary (but not only) pre-requisite for hydrolysis. For example, no reaction was observed for monomeric CuMe2– anions, whereas the reactions of LiCu2Me4– and Li2Cu3Me6– were much faster. Following the successful characterization of organocuprates, their synthetically useful coupling reactions with alkyl halides were probed. ESI mass spectrometric experiments, supported by electrical conductivity measurements, indicated that LiCuMe2•LiCN reacts with a series of alkyl halides RX (R = Me, Et, nPr, nBu, PhCH2CH2, CH2=CHCH2, and CF3CH2CH2). The resulting Li+Me2CuR(CN)− intermediates then afford the observable Me3CuR− tetraalkylcuprate anions upon Me/CN exchanges with added MeLi. In contrast, the reactions of LiCuMe2•LiCN with neopentyl iodide and various aryl halides gave rise to halogen-copper exchanges. Concentration- and solvent-dependent studies suggested that lithium tetraalkylcuprates partly form Li+Me3CuR− contact ion pairs and presumably also triple ions LiMe6Cu2R2−. According to theoretical calculations, these triple ions consist of two square-planar Me3CuR− subunits binding to a central Li+ ion. Upon fragmentation in the gas phase, the Me3CuR− anions undergo reductive elimination, yielding both cross- (MeR) and homo-coupling products (Me2). The branching between these channels showed a marked dependence on the nature of R. The fragmentation of LiMe6Cu2R2− also affords both cross- and homo-coupling products, but strongly favors the former. This was rationalized by the preferential interaction of the central Li+ ion with two Me groups of each Me3CuR− subunit, which thereby block the homo-coupling channel. Finally, the reactivity of organocuprates in conjugate addition reactions was investigated, with cyano-substituted ethylenes C2Hn–4(CN)n, n = 1 – 4 as Michael acceptors. In the case of acrylonitrile, n = 1, polymerization was induced, but no reactive intermediates were detected. In contrast, the reaction with fumaronitrile, n = 2, permitted the detection of π-complexes in different aggregation states. The identities of the latter were confirmed by the release of intact fumaronitrile upon their fragmentation in the gas phase. The reactions with 1,1-dicyanoethylene, n = 2, did not halt at the stage of the π-complexes, but proceeded all the way to Michael adducts. In the case of tricyanoethylene, n = 3, dimeric polycyano carbanions were formed. For tetracyanoethylene, n = 4, the reaction instead leads to Cu(III) species, which undergo reductive eliminations. Thus, all intermediates commonly proposed for the conjugate addition of organocuprates to Michael acceptors were detected, providing strong evidence for the currently accepted mechanism.

Living on Earth
Living on Earth: October 31, 2003

Living on Earth

Play Episode Listen Later Oct 31, 2003 51:50


MTBE & Liability / Paying at the Pump / Environmental Health Note/ Aspirin & Heart Disease / Almanac/The Big Freeze / Bat Hang-out Causes Problems for Local Melbourne Gardens / EU Chemicals / Snake Crossing / Emerging Science Note/Ocean Life Evolution / California Wildfires / Healthy Forests / The Beast in the Garden

Living on Earth
Living on Earth: October 31, 2003

Living on Earth

Play Episode Listen Later Oct 31, 2003 51:50


MTBE & Liability / Paying at the Pump / Environmental Health Note/ Aspirin & Heart Disease / Almanac/The Big Freeze / Bat Hang-out Causes Problems for Local Melbourne Gardens / EU Chemicals / Snake Crossing / Emerging Science Note/Ocean Life Evolution / California Wildfires / Healthy Forests / The Beast in the Garden

Living on Earth
Living on Earth: October 31, 2003

Living on Earth

Play Episode Listen Later Oct 31, 2003 51:50


MTBE & Liability / Paying at the Pump / Environmental Health Note/ Aspirin & Heart Disease / Almanac/The Big Freeze / Bat Hang-out Causes Problems for Local Melbourne Gardens / EU Chemicals / Snake Crossing / Emerging Science Note/Ocean Life Evolution / California Wildfires / Healthy Forests / The Beast in the Garden

Living on Earth
Living on Earth: October 31, 2003

Living on Earth

Play Episode Listen Later Oct 31, 2003 51:50


MTBE & Liability / Paying at the Pump / Environmental Health Note/ Aspirin & Heart Disease / Almanac/The Big Freeze / Bat Hang-out Causes Problems for Local Melbourne Gardens / EU Chemicals / Snake Crossing / Emerging Science Note/Ocean Life Evolution / California Wildfires / Healthy Forests / The Beast in the Garden

Living on Earth
Living on Earth: October 31, 2003

Living on Earth

Play Episode Listen Later Oct 31, 2003 51:50


MTBE & Liability / Paying at the Pump / Environmental Health Note/ Aspirin & Heart Disease / Almanac/The Big Freeze / Bat Hang-out Causes Problems for Local Melbourne Gardens / EU Chemicals / Snake Crossing / Emerging Science Note/Ocean Life Evolution / California Wildfires / Healthy Forests / The Beast in the Garden