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 don’t use the electron withdrawing fluorine on their arylalcohols they might better stabilize the U⁺⁶.

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

Mitch

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 is 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…

Mitch

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.

Mitch

Here’s an article that may be of the members’ interest. Chemical and Engineering News published a cover story about the latest development in Yucca Mountain repository for nuclear waste. It has a comprehensive review for the history and experts’ opinions on this issue, but not much new information. For the full text, check out the link: The Forever Waste .

For those who are following the element 122 discussions, a fellow DNCT member wrote an excellent review on the validity of their data. To learn more or join the discussion, check out Addressing Marinov’s Element 122 Claim.

Noel

[1] Photo of Yucca Mountain from Wikipedia

I haven’t had time to look at it closely, but a paper showed up on the physics arXiv claiming possible discovery of element 122. They were analyzing thorium-containing solutions in an inductively-coupled plasma sector field mass spec (ICP-SFMS) and saw a peak they could not explain at mass 292. They argue this should be from an element with atomic number 122. They cite an abundance relative to thorium of about 1E-12. My early, somewhat uninformed, guess is that a contaminant is responsible, but it should make for an interesting read.

PDF Article Link

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

Mitch Garcia, member of DNCT and our fellow blogger, will be featured on American Latino TV this weekend. He’ll be talking about the field of nuclear chemistry and how he got there. In addition, he’ll be discussing the popular chemical education tools that he has created (ex. www.chemicalforum.com). Tune in to support a fellow DNCT member!

A complete listing of available channels is available at:

http://aimtvgroup.com/altv/wheretowatch/

Yesterday the blog was supposed to be debuted at the NUCL business meeting here at the Morial Convention Center in New Orleans. Unfortunately, there was no projector available to do the demo with (although it was mentioned that we paid for it), so Noel and I did the best we could to describe the functionality of the site.

So far we have seen several new members sign up and have already gained another author. So sign up, and take part in the latest tool for the DNCT.

Also, the talk Noel and I gave about online social networking tools (this blog specifically) in a CHED symposium can be found here:

Incorporating Online Social Networking tools to Facilitate Participation and Discussion in Nuclear Chemistry.

With the 235th ACS National Meeting kicking off in just under a week, you may want to start mapping out what events you plan on attending. The entire technical program for the spring 2008 meeting is available here.

However, here’s some info on sessions you really should attend:

1.) Monday, April 7 2008, at 4:35 PM Hilton New Orleans Riverside — Oak Alley, Oral #768
Incorporating social networking tools to facilitate participation and discussion in nuclear chemistry
M. N. Ali, Noel N Chang, Mitch A. Garcia, Heino Nitsche

That will be the semi-grand unveiling of this blog. Be sure to attend to learn more about how to get involved in the blog, and hear about future development plans.

2.) Monday, April 7 2008, at 8:35 AM Hilton New Orleans Riverside — Oak Alley, Oral #184
Development of chemical forums, blogs, wikis, RSS feeds, crowdsourcing, and social bookmarking websites for chemistry
Mitch A. Garcia, M. N. Ali, Noel N Chang, Heino Nitsche

Attend this session to learn more about how to use new internet technologies for research and teaching purposes.

For the DNCT sessions, here is how the timing has worked out.

See complete list of sessions

Legend A = AM; P = PM; D = AM/PM;

Don’t forget that the NUCL business meeting from 5 - 6pm Monday evening at 211 — E. Morial Convention Center.

Add yet another way for the government to track you to the list. A University of Utah team led by geochemist Thure E. Cerling and ecologist James R. Ehleringer have shown that the Hydrogen and Oxygen isotopes in human hair correlate with those isotope ratios in local tap water. (doi: 10.1073/pnas.0712228105)

We all expect that a persons diet greatly affects the concentration of certain commonly found isotopes. 13C, 15N, 34S, 40K are all present in our bodies, though in such small quantities that they don’t appear to have a significant effect on our health. Ideally you could measure the concentration of these isotopes, or their relative isotopic ratio, and learn the dietary habits of an individual. By taking into account small differences caused by fractionation events during metabolism and the larger differences in 15N values, the isotopic ratios of 13C, 15N, and 34S provide limited geographic based information about the origins of a food source.

Cerling and Ehleringe, however, chose to look at a more unlikely source for traceable isotopes that turns out to be more useful and easily detectable.

Hydrogen (²H) and oxygen (¹⁸O) isotope ratios of organic matter are more useful, because ²H and ¹⁸O values of precipitation and tap waters vary along geographic gradients (10, 11). Although differences in the ²H and ¹⁸O values of scalp hair have been noted in humans (12), less is known about diet–organism patterns of ²H and ¹⁸O values. Four potential sources can be important: dietary organic molecules, dietary waters, drinking waters, and atmospheric diatomic oxygen.

The ²H and ¹⁸O values of keratin in human hair should be influenced by a number of factors during synthesis within the hair follicle, including all dietary and atmospheric sources of H and O. Bear in mind, however, that their discussion was limited to the ²H that was not subject to postsynthesis isotopic exchange. Cerling and Ehleringe hypothesized that variations in the nonexchangeable ²H and ¹⁸O values in human keratin could provide insights into water and human diet across geographical regions if the hydrogen and/or oxygen isotopes from these sources were recorded in human hair.

After developing a model to account for the difference in the isotopic ratios between drinking water, body water and the actual scalp hair, Cerling and Ehleringer tested the model by attempting to predict the geographic region of origin of individuals based on the isotope composition. They obtained ²H and ¹⁸O values in hair sampled from 65 cities in 18 states. Their model which was a function of drinking water, bulk diet, and protein isotope ratios, explained more then 85% of the observed variation and strongly reproduced the relationship of the isotopic composition of hair samples to that of local drinking water.

Plots of the relationships between mean H isotope ratios (Upper) and mean O isotope ratios (Lower) of human scalp hair and tap water for samples randomly acquired in cities representing 18 states across the United States. The lines through the data in each plot represent model-predicted values based on local tap water and a continental supermarket diet.

The really interesting part, though, is this:

Based on the geographical distributions of the isotope ratios of tap waters and the assumption of a “continental supermarket” dietary input, we constructed maps of the expected average H and O isotope ratios in human hair across the contiguous 48 states. Applications of this model and these observations are extensive and include detection of dietary information, reconstruction of historic movements of individuals, and provision of region-of-origin information for unidentified human remains.

So now using a sample of a persons hair, not only can we find out exactly who they are (DNA) we can find out where they are from…as long as they are drinking local tap water.