Chemistry Blog

ACS Front Page

Looks like ACS is giving the Cold Fusion press conference some nice front page real estate. It is currently prominantly displayed on http://www.acs.org/

I’m getting embarrassed for ACS at this point.

Our recent coverage of the Cold Fusion Press conference: Cold Fusion Has Its Press Conference, Monday Update from ACS in SLC

Pic of the ACS front page is below.

Mitch

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Cold Fusion Has Its Press Conference

Jeremy and I scored press passes to the recent Cold Fusion Press Conference at the ACS 2009 Spring Meeting. Unfortunately for them I’m a nuclear chemistry PhD student. Jeremy did a quick wrap-up of the press conference,^[CB] but I thought it would be useful to have a critical chemist perspective of their recent announcement. The press conference did nothing to address the violation of the most elementary of chemistry and physics that I painstakingly explained in this old post titled “The difference between cold fusion and cold fusion“, but I’ll move on to address their statements.

As this was a press conference and not a scientific talk there wasn’t any data that I can point to as evidence for a cold fusion claim. However, we can tear some sanity from their own words. I asked why they haven’t observed any gamma rays from their cold fusion experiments. Pamela Mosier-Boss was quick to reply that they indeed did measure gamma rays, but they “came in bursts… and are averaged away [over the duration of the experiment]“. Dissect that statement and reflect on it as a scientist. Think to yourself: “Hmmm… clusters of peaks coming all of a sudden but randomly”, “Hmmm… as they run the experiment they see these peaks average out?”, “What does this mean?”. You don’t have to be a spectroscopy expert to figure this one out. The answer is simple, they measured background. Background is a random process, it will come in bursts, they may even cluster to make a peak for a short time, but when you run it over the course of the whole experiment it is “averaged out”; that my friend is background you measured.

At an other point of the conference Mahadeva Srinivasan claims to be able to measure tritium, neutrons, and other ionizing radiation not by actually measuring them, but indirectly from looking at his electrodes and observing craters and holes and trying to ascribe the radiation that caused it. Sounds sort of reasonable unless you’ve ever done any electrodeposition, which is what the process he described would yield if running current through a wire. Here is a picture of an electrodeposited layer of europium oxide my fellow colleagues made in the lab.

You can see craters and valleys in the image. I hope their electrodes didn’t look anything as awful as this, but you can see for yourself that electrodeposition can create ugly surfaces. Which was a major reason for the Thin Film community’s move away from electrodeposition and embrace of Sol-Gel techniques, because it causes less cratering and produces homogeneous and uniform films.

So should I believe the claims of a scientist who does not understand the difference between background and peaks? Should I believe a scientist who doesn’t understand the basic consequences of his own technique? You don’t even have to be a nuclear chemist to call bull-shit on this one.

I want to end this on a positive note, because I’ve spent a lot of time hammering these cold fusion people over the years. Honestly, if they are measuring more energy out of their systems than the energy they are putting in, then this is fantastic news. If they see excess heat, then they need to chase this line of inquiry down. But nuclear fusion is not the right path. I truly want to believe these people are capable of measuring the amount of energy in their system versus the energy out correctly. But the electrochemistry they are performing is non-reversible and that makes energy accounting, in their dynamic system, a very difficult mess. The simple act of having gas bubbles float from your electrodes will deposit more energy into your solution, due to friction, then you would expect. And frankly, after listening to these people talk for 45 minutes I don’t believe they are capable of correctly accounting for energy in a dynamic system.

Mitch

P.S. Make up your own mind, a link to the press conference is here, Cold Fusion Press Conference. I ask my question around the 28 minute mark. Aaron Rowe from wired science blog is now my favorite science journalist, his question is asked at 34:50 minute mark.

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32-electron chemistry

We all remember learning about octets and valence electrons in school. We may also remember the first time we saw an 18-electron transition metal complex. This week Dognon et al. discuss the possibility of 32-electron organometallic complexes.^[JACS] In order to reach 32-electrons, f-orbital participation is essential. Below is a picture of a hypothetical organometallic complex with 28 carbons in a cage around an actinide element.

Although these systems are not new, as the Smalley group made U@C₂₈ in the gas-phase in ‘92,^[Science] Dognon et al. examine a series of these systems for different actinides. The major conclusion is that the plutonium system is theoretically predicted to have the largest bonding energy for its Pu⁴⁺@C₂₈ complex. Since fullerenes and the intercalation of metals often only need heat to be synthesized, I wouldn’t be surprised if these complexes have already been made but missed as impurities and byproducts.

Link to paper: A Predicted Organometallic Series Following a 32-Electron Principle: An@C28 (An = Th, Pa+, U2+, Pu4+)

Update 1: Jyllian Kemsley also covered it at C&EN — Stable Caged Actinides Proposed(subscription)

Mitch

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ACS Day 4: New Uranium (VI) Chemistry (non uranyl)

Hayton, from Santa Barabara, presented his recent work with uranium (VI) compounds. The chemistry of Uranium (VI) is dominated by the formation of Uranyl (UO₂)²⁺. However, the Hayton group was able to synthesize and fully characterize U(O^tBu)₆ (1). The compound was reacted with aryl-alcohols in the hope of producing U(OAr)₆ (2) compounds, shown below.

Unfortunately, due to the presence of lithium from earlier steps he prepared (3) and after doing a better job ridding his reagents of lithium produced (4).

The work highlights the difficulty in synthesizing stable uranium (VI) compounds, but perhaps if they didn’t use the electron withdrawing fluorine groups with their arylalcohols they might better stabilize the U⁺⁶.

More Info: Synthesis and Characterization of Three Homoleptic Alkoxides of Uranium…

Mitch

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ACS Day1: New Actinide Solvent Extractors

The ability to selectively extract actinides out of nuclear waste remains a hot research topic. Today Hancock, from Wilmington, gave a presentation on several tetradentate ligands that bind to actinides more strongly than other smaller metals. The systems he investigated are shown below.

The PDA system was highlighted for its rigidity, fluorescent potential, and the size of its cavity. Some formation data below.

These types of systems look promising and are a nice upgrade over traditional old-school extractors like tributylphosphate(TBP).

Much of the talk was covered in this recent paper: Affinity of the Highly Preorganized Ligand PDA…

Update 1: A Chemical Sabbatical linked here: Hooray! Aqueous Transition Metal Chemistry Talks

Mitch

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ACS Endorses Quackery

I’ll be attending the ACS-Philadelphia conference next week. One of the sessions sponsored by the Environmental division is called “New Energy Technology” on Wednesday morning out at the DoubleTree-Maestro B. The title implies itself to wonderful talks discussing frontiers in applied energy chemistry. Unfortunately, the session is completely dominated by the left-field cold fusion people. A list of the talks are shown below

• Cold fusion in light of green chemistry (Jan Marwan)
• Low energy nuclear reactions research: 2008 update (Steven B. Krivit)
• Overview of LENR research: Critical steps on the pathway to technology(Michael Charles Harold McKubre)
• Macroscopic quantum dynamics and the problems of loading in Pd-H(D) systems (Antonella De Ninno, Emilio Del Giudice, Antonio Frattolillo)
• CR-39 studies of Pd/D codeposition (P. A. Mosier-Boss, Stanislaw Szpak, Frank E. Gordon, Lawrence Forsley)
• Study of the nanostructured palladium deuterium system (Jan Marwan)
• Sonofusion from deuterons to helium (Roger Stringham)

My feelings on cold fusion research have been stated previously here: The difference between cold fusion and cold fusion

It would be in good taste to attend the session, and let them have the opportunity to present their research, but I question whether I could sit through it. If you find yourself bored on Wednesday morning and ready for a lively debate, I’d recommend attending this session.

P.S. Expect dispatches from the conference. I’ll be covering a wide slice of the sessions with my new ACS press-pass: ACS-2008 Philadelphia.

Mitch

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Addressing Marinov’s Element 122 Claim

Note 1: It is an unfortunate consequence of the internet age to be forced to address public misconceptions of research that is published by press-release rather than peer-review. Society & science are not served well from the absence of even cursory peer-review. It should be noted that some of the authors in the paper have a colorful past, but the critique below will be on evidence provided within the manuscript the authors have submitted.

In Marinov’s element 122 paper, Evidence for a long-lived superheavy nucleus.., a fantastical claim is made for the identification of element 122 with standard thorium samples. It should be strenuously noted that element identification (id est determination of the number of protons, atomic number (Z)) can not be definitively determined by mass spectrometry when the exact mass of the element is not known. Yes, there are many models that can extrapolate what the mass of an unknown isotope should be, but overly broad best guessing is not the way science in conducted.

The paper infers a mass accuracy for their mass spectrometer of 0.040 amu and this error will be used to determine the validity of their data. The first figure showing evidence of element 122 is shown below.

The figure shows their data from summing the thorium sample 5 times from their 1st run.

As the figure is lacking a significantly intense peak near 292.010 amu corresponding to ²³⁸U⁴⁰Ar¹⁴N⁺ that is seen in later runs, I would be forced to chalk those signals to inherent noise in the instrument, especially as no blank spectrum was provided as reference for this data series.

The figure shows their data from summing the thorium sample 60 times from their 2nd run. Top spectra is sample, bottom spectra is of the blank.

The peaks from ²³⁸U⁴⁰Ar¹⁴N⁺, mentioned earlier, can be clearly seen in this spectrum. The authors fail to scale the blank’s intensity (y-axis) to the same level as the sample which makes comparisons unnecessarily difficult. The blank’s intensity axis is larger than that of the samples, which is very unusual as one tends to have to zoom into a blank rather than zoom out to make a scientific point. I am also confused as to what the peaks labeled x1/5 mean (was data altered to scale these peaks down?), I do not know. As the x1/5 peaks in the blank are not seen in their thorium sample, one has to wonder why this is so. Has the detection limit already been reached?

The figure shows their data from summing the thorium sample 200 times from their 3rd run. Top spectra is sample, bottom spectra is of the blank.

This data set has the largest statistics as it is a sum of 200 spectra. The blank in this figure has obvious peaks near 292.230 and 292.280 amu. The blank peak at 292.230 is also seen in the sample spectrum, and is now a dominant peak in that spectrum. Any good data set should be at least 3 times the peak height of blank noise, when the signals are so close together, but this is not the case in this figure. Even if referencing the 2nd blank peak at 292.280, the signals attributed to element 122 are at best 2-2.5 times blank background peaks.

The claim that there was no molecular ion formation from hydrocarbon presence from their vacuum pump is also not realistic. From the sensitivities claimed in the paper the presence of pump oil should of been detected.

The authors give several theoretical hypotheses why element 122 should be stable, but these claims will not be evaluated as I see no convincing evidence of the identification of element 122.

Note 2: Link to paper: Evidence for a long-lived superheavy nucleus with atomic mass number A=292 and atomic number Z=~122 in natural Th
Note 3: First coverage of claim was from The Physics ArXiv Blog: First superheavy element found in nature

Mitch

Note 4: Mitch is a nuclear chemistry PhD student at UC Berkeley studying the chemistry and physics of elements above Lawrencium (Z>103) in the Heavy Element and Actinide Chemistry group.

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Irradiation to enhance food safety

Does anyone remember the E. Coli breakout back in 2006? I do. There has never been a quicker way to convince a 19-year-old to eat vegetables until you take lettuce out of their sandwiches for a couple of months.

According to the LA Times report[1], these greens are washed in potent chlorine bath, often up to three times, before they are bagged and shipped to the retailer. This standard procedure has a reported 90% effectiveness in killing the microorganisms that may cause harmful effects to the human body.

I don’t know about you, but I would rather not take that 10% chance to get sick. In the single breakout of E. Coli due to cross contamination with the cattle back in 2006, 200 people became ill and three lost their lives. That’s the 10% chance that nobody should have to take.

This past month at the ACS National Meeting in New Orleans, researchers from the USDA presented their findings and results of radiation treatment of fresh produces. Irradiation of high energy beams of photons or electrons, said the scientist, can disrupt the DNA of these pathogens. While the chlorine rinse offers a 90% effectiveness in killing bacterias on the surface of the leaves, it is not able to penetrate beneath the surface. Irradiation method has a reported >99.9% effectiveness in wiping out pathogens such as E. coli, salmonella and listeria, and the high energy beams allows penetrating power that works inside and outside the leaves.

Some members of the scientific community are calling irradiation one of the “few intervention steps that indeed can penetrate the leaf surface and kill microorganisms.”

Irradiation for enhancement of food safety is permitted for some hamburger meat, poultry and spices, but not for fruits and vegetables. However, there has not been any health problems associated with eating irradiated food. So why is FDA steering away from adopting an improved method that could potentially save lives?

Consumer experts and food safety researchers offer some of their speculations:

1. Irradiation may damage the apparence of the product, which may not be as appealing to the customers
2. Nobody would buy lettuce from a bag with a radiation sticker
3. The treatment could shorten shelf lives of the products
4. Technically, irradiated produces cannot be certified organic

Though reasonable, it is hard to believe that the above mentioned points would stop either FDA or independent research institutes from further investigating in a method that could possibly be so much more potent in eradicating pathogens than the existing practice. Perhaps these novel ideas would not suffer as much if we could deliver more transparent and correct ideas regarding the applications of radiation.

Using innovative ideas to improve the quality of our everyday lives, isn’t that what science is all about?

Noel

[1] USDA scientists say irradiation could be key to food safety

P.S. True to scientific spirit and for the benefit of the minorities out there, I will summarize and translate my discussion in lolcat. I can has radeashuns: on ur vegitablez, keelin ur baktiriaz.

Edit: Originally mentioned by Bethany Halford and Lisa Jarvis in Chemistry Newsbytes.

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