Über eine neue Art von Strahlung

Chance favors the prepared mind

—Louis Pasteur

Wilhelm Conrad Roentgen (1845-1923)

Wilhelm Roentgen (Röntgen for the purists & pronounced sort of like runt-ghen, i.e., with a hard "g") rocked the scientific world when he published Über eine neue Art von Strahlung ("On a new Type of Radation"). The classic 1896 paper described experiments he had conducted the preceding fall. Just five years later in 1901, Roentgen received the very first Nobel Prize in Physics. The citation recited:

"in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him." 

Roentgen didn't want "his" rays to be named after him, and so (in the English-speaking world at least) they are called by the term he coined: X-rays, wherein the "X" stood for "unknown". An account of Roentgen's serendipitous discovery of X-rays is well documented in the Wiki bio linked above. I have a copy of that first paper (in German) published as Chapter 11 in a remarkable book called The German Scientific Heritage by Reginald Phelps & Jack Stein (Copyright 1962 by Holt, Rinehart and Winston, New York). Roentgen wrote in that classic "tall-by-the-brook-standing-tree" syntactical style that seems so uniquely German. Yet Roentgen was an impeccable experimentalist and had already discovered many of the interesting properties of X-rays and set them forth in that first publication. Most astonishing, and perhaps convincing, was his inclusion of the first ever Röntgenbild: an X-ray photograph of his wife's hand, complete with ring:

Hält man die Hand zwischen den Entladungsapparat und den Schirm, so sieht man die dunklen Schatten der Handknochen in dem nur wenig dunkleren Schattenbild der Hand.

Holding the hand between the discharge apparatus and the screen, one sees the darker shadow of the hand bones within the lighter shadow of the hand.

I bring all this up for two reasons: First: heavier atoms in molecules and hence materials are easier to see with X-rays than are lighter ones. Bones are mostly made of calcium, phosphorus and oxygen: the former two elements #20 and #15, are twice as heavy as the "heavy" elements that make up soft tissue, viz., carbon (6), nitrogen (7) and oxygen (8). Hydrogen (1) is the hardest atom of all to see with X-rays. This is also why MRI is such a great complimentary technique to X-rays: it mainly locates (visualizes) hydrogen in water and attached to carbon in soft tissues.  Chemists recognize the same complimentarity between X-ray crystallography and NMR spectroscopy.  Metals like gold (79) stand out even more sharply by X-ray.  Roentgen realized all of this in his now classic paper in which he tested the transparency of various materials.

     Another reason to bring this all up is that screening methods at airports have been in the news lately. X-rays are used to screen luggage and people for bombs and contraband. A good primer on their use can be found here.  I'm still looking for a good reference on the techniques used for full body scans, especially since the apparent threat of bosom bombers would appear to challenge the current systems and methods in place. Plastic explosives like PETN can be easily distinguished from silicone breast implants, but apparently not without effort.

Meanwhile, Frau Roentgen is ready for her close-up now:

Status Quo vs. Change

"...two important aspects of inorganic chemistry (in fact, of chemistry in general) are structure and reactivity.  Someone has said that all of physical science consists of this duality.  In physics we could speak of statics and dynamics, and by analogy in everyday life, the status quo and change."

James E. Huheey Inorganic Chemistry: Principles of Structure and Reactivity 2nd Ed

More Elemental Musings

The single most important piece of scientific literature is, in my opinion, the periodic table.  Those who understand what it means, and what it actually implies, have mastered more science than most professors ever will.  This may sound like an exaggeration, but come with me and I think that I can prove it to you.

         Translator, writing for The Daily Kos

The Dailykos!!  Whoever "Translator" is (and he reminds me of Derek Lowe), he or she put together a wonderful historical synopsis of the periodic table. I highly recommend reading at least the historical section to get a flavor for what went into the development of the periodic table. 

I would add just one thing to Translator's fine discourse, and that is that the modern appearance of the periodic table might lead one to think that there are gaps between elements:

For example, look at the huge gap between H and He, which essentially spans the whole table.  Look in particular at the gap on moving from 4 to 5, ie., beryllium (Be) to boron (B). Why aren't there elements filling those gaps?  The answer (besides the "cute" one that there are no whole numbers between 1 and 2 nor between 4 and 5) is that those gaps are a consequence of the two dimensional presentation of the table which has become standard. While the table doesn't map anything physical in the sense of a photograph of unseen things, it might be useful to think of the gaps in the periodic table in the same way that certain flat maps depict a spherical earth:

In essence, what the periodic table repesents cannot be perfectly rendered in two dimensions!
There have been numerous alternative presentations of the periodic table: spirals, pyramids, spheres, etc, none of which ever caught on as the iconic image above did. Several of the alternatives are presented here.

Give Blood

1/31/52  Fort Knox KY

Dear Mom Dad and all.

I haven’t heard from you for a few days so I thought maybe I owed you a letter. I got a letter from J_ two  days ago. He sent some pictures, so I am sending them on to you. [1]  I got some made and am sending them. Today is payday so in a couple of weeks a check will be coming.

It snowed Tue. About a inch and was down to zero. Today it's warm again.[2]

I got a chance to go to Nashville this weekend so I think I will go.

I broke my watch jumping off tanks so I will have to get it fixed soon. I started to write this before mail call and got your letter.

I didn’t send J__ a picture of him with a pack on his back so you can send him one.

Its too bad about Aunt Bertha.

We won’t have any training tomorrow. In order to get out of it you have to give a pint of blood. [3]  Only about 10 out of 200 aren’t giving any. Our Captain said it is best to start a blood bank now, because someday we might need it. I think I can afford a pint.

Did R_ ever get the fender skirt taken off my car?  I might sell my car if I can get enough out of it this spring.

I had two more teeth filled today. I am all done with them now for at least a year.

Its time to sign off for now. I will write the first of the week after I get back from my trip.

Love

V.

________________________________

[1] The photos are long lost I'm afraid.
[2] Flood waters building.
[3] Current Army regulations regarding blood donations: link. I have tried on several occasions to give blood to the Red Cross but have been disqualified because of my residence time in Switzerland and then Germany in the early '90's.  Apparently, I am at risk for developing Mad cow disease (and just from consuming over-priced meat in Switzerland). I've always protested that I could barely afford to eat meat in those days but they never listen. It all seems a little unfair, rather like the Koreans refusing to eat American beef last year for the same reason.
My brain has always soaked up knowledge like a sponge. But my brain is not spongiform like those afflicted with Mad Cow are, as confirmed by a recent MRI.

Beryllium: Such a Sweet Precious Gift!

Different variations of beryl, including 1. golden beryl crystal, 2. heliodore. 3. emerald, 4. aquamarine, 5. morganite

My daughter went on a field trip the other day to the Gemological Institute of America GIA, located in nearby Carlsbad. She learned about precious gems of all sorts, and even came home with a perfect (albeit small) marquise-cut emerald. Emeralds got me to thinking about beryllium.
The root word of beryllium is old and familiar: It lurks beneath the surface of the commonly used word brilliant:
brilliant
1680s, from Fr. brilliant "sparkling, shining" prp. of briller "to shine" (16c.), from It. brillare "sparkle, whirl," perhaps from V.L. *berillare "to shine like a beryl," from berillus "beryl, precious stone," from L. beryllus (see beryl). In reference to diamonds (1680s) it means a flat-topped cut invented 17c. by Venetian cutter Vincenzo Peruzzi.

Beryl and emeralds were known to Pliny the Elder nearly 2000 years ago and he first observed a physical similarity between the two. In the Middle Ages, transparent, colorless beryl was used to make optical lenses, whence the German word Brille which today still means eyeglasses. The invention and manufacture of actual glass spectacles developed in Italy in the 13th century and improvements followed closely with the development of optics.
The minerologist R.-J. Haüy also observed the remarkable similarity between beryl and emerald (hardness and density), and he persuaded the pre-eminent chemist/pharmacist of his time (late 18th century) Louis Vauquelin (of Paris) to analyze the stones to see if they were chemically alike. In 1798, Vauquelin showed that both minerals contained not only alumina and silica as had previously been known, but also a new element, which he extracted as the oxide from emerald. Fredrich Wöhler first prepared metallic beryllium by reducing BeCl_2, with potassium metal. Thus the new element beryllium was discovered.

One caveat: until around 1948, beryllium (symbol = Be) was also known as Glucinium (symbol Gl), reportedly because of the sweetish taste of its chloride salts.

WARNING: Beryllium is considered to be highly toxic so do not, repeat do not taste or chew your precious emeralds!

"We heard that we were going to Germany"

January 20, 1952
Fort Knox, KY


Dear Mom, Dad and all,
I got your letter Fri, and the package Sat. I also got a letter from J__ on Sat. and will answer it tomorrow night. We heard that we were going to Germany when we get through basic but you can’t tell, for sure. [1]  I am going to Nashville the first of the month.
We got some more clothes today. 1 pair of socks, 1 cap, 1 jacket, 1 tee shirt, glove liners. I didn’t even dress up this weekend and go anyplace. It thundered and lightening Sat night and it rained quite hard. [2]
We have been having trouble lately with boys going AWOL. [3]  I guess some of them just can’t stand to be away from home. It isn’t so bad yet, but I think it will be a lot worse once we leave the states. We got one boy here from Penn. that never leaves the camp. I guess he was a farmer. I think Jim J__ is going skating next weekend at Louisville. The lights will be going out in about 15 min so will have to sign off for now.
love
V.

P.S. J__ didn’t have much to say. Mostly about cars and what kind he wanted to get. Henry J can’t afford a Merc. [4]

--------------------------------------------------------------------
[1] President Truman believed that the war in Korea might be a ploy to concentrate all American resources in Asia, thus leaving western Europe open to invasion by the Soviet Bloc. The Berlin Airlift had already occurred in 1948, along with the Soviet occupation of Czechoslovakia in 1948. NATO was created in 1949 because of the perceived Soviet threat towards Western Europe. After the start of the Korean war, the United States deployed 4 divisions to Europe, culminating in the creation of the USAREUR in 1952. By this time, the US role in Germany had officially changed from an occupying force into an allied defender of the newly-formed German Federal Republic (West Germany).

[2] Heavy flooding occurred in Ohio, West Virginia, and Kentucky that year, perhaps also due in part to heavier than normal snowfall. The flooding was bad enough to prompt a flyover visit from President Truman just a couple weeks later: ref.

[3] According to one source, 84 enlisted men from Fort Knox were disciplined for absences around that time. ref.

[4] I recall that the late '40s and early 50's Mercs were favorites amongst my dad and uncles. I'm not sure which particular year they lusted after, but I'm sure it was one of these: Link.

Can Lithium Help Detroit?

Bolivian Lithium

Back to chemblogging for a bit.  Hmmm, let's see...I left off quite a while ago with lithium, helium, and hydrogen. I'll finish off lithium before moving onto beryllium, the fourth element.

Lithium Pharmacology
Lithium (or more accurately Li⁺) is pharmacologically active and is used to treat bipolar disorder. It's not at all clear to me (nor to Wiki) how this works.  Let's improvise. Here's my armchair analysis:
Observations: (1) In the body, Li⁺ is awash with lots of similar cations, namely, sodium (Na⁺) and potassium (K⁺). Moreover, there's realistically no way that one could swamp the body with so much Li⁺ that it would simply displace Na⁺ and K⁺; moreover, both sodium and potassium are essential and we'd die without them. Better to look for something that Li⁺ does better than Na⁺ and K⁺ do.
(2) Lithium is found in nature as lithium carbonate (in nature, elements tend to be found with other elements for which they have natural affinity). There is also experimental evidence that Li⁺ binds better to carboxylate groups, –CO₂^(-) than do either Na⁺ or K⁺:  ref.  In other words, Li⁺ has a higher affinity for the carboxylate functional group¹ and could displace a greater concentration of Na⁺ and K⁺. The pharmacists already know about this special affinity and Li⁺ is commonly formulated as lithium citrate:

Notice that the citrate has three carboxylate groups. Lithium citrate was once an ingredient in 7-Up, the Uncola, but was removed in 1950. It's important to realize that once in the body, the citrate part is easily chewed up and metabolized, leaving three Li⁺ cations, each in search of a carboxylate. 
(3) Carboxylates are ubiquitous, being the terminal side chain of common amino acids aspartic acid and glutamic acid.
(4) Glutamate is implicated in all kinds of neurochemical functions.

Hypothesis: Li⁺ displaces Na⁺ to such an extent as to affect the role of glutamate. The carboxylate functional groups are intimately involved in how neurotransmissions occur.  Essentially what lithium does is to monkey wrench this somehow. Anyway, it's just food for thought. Prove it wrong. A cursory Google search suggests there is something to this: ref, ref, and ref.

There are other proposed mechanisms of action for lithium and, if interested, check out the Wiki page here.  I love ill-defined chemical mechanisms, especially when an element is involved.  I'll return to this theme when I consider the essential role of boron (element 5, after beryllium) in plants. Meanwhile, I hope a lithium expert finds this blogpost and jumps in to correct me. I will retract the hypothesis.

Lithium Ion Batteries
Lithium ion batteries power lots of everyday electronic gadgets like cellphones, laptops and other electronic gadgets and, hopefully soon, lots of electric cars. Several generations of rechargeable batteries include lead-acid, nickel-cadium, nickel-metal hydride (NMH), lithium, and now lithium ion. By far and away the lithium ion battery is superior--enough to revolutionize the small gadget industry. Why is that?
First, it's very light. Lead-acid (think 12 V car batteries) and NMH batteries (think Prius batteries) are very heavy. Old fashioned carbon-zinc batteries are light but are not rechargable). Weight is very counterproductive deadweight when you're trying to move something around.
Second, lithium has a relatively high redox potential² for conversion of Li⁺ to lithium metal. Early lithium batteries did in fact use lithium metal and lithium ions, however it was quickly realized that the dangers of using lithium metal could not be overcome.  Lithium is the most electropositive element and would seem well suited for 3 V applications. If you consider that the nominal voltage of common batteries: viz., AA, AAA, C, and D is, 1.5 V you'll realize that a 3.0 V battery would be useful, given that 3 V is commonly acheived by using two 1.5 V batteries in series. (This is why so many devices use two such batteries head to tail).
Lithium’s exceptional light weight is currently wasted in present generation batteries, especially automobile-sized ones: the battery train for the Chevy Volt weighs about 600 lbs. Much of this weight is due to cobalt oxide present. However, next generation breathing batteries intend to do away with the relatively heavy cobalt or iron-based components. I really hope the Volt does well and I suspect it will. Detroit needs a home run like the Toyota Pruis. I think the Volt is especially suited for the urban coastal hipsters. Me? I'll stick with diesel for the time being.

Lithium in Synthetic Organic Chemistry

The wonderful and unique properties of lithium just go on and on. A single inorganic compound, LiAlH₄ or LAH in the parlance, enabled the synthesis of entirely new classes of compounds, including pharmaceuticals. Organolithiums are a class of compounds wherein lithium replaces a hydrogen atom.  They are useful because they allow carbon in a hydrocarbon to behave as a negatively charged anion-a carbanion. Carbon normally engages in chemical reactions as an electrophile, i.e., having a tendency to attract negatively charged coupling partners. An obvious example of this is peptide synthesis in which donor nitrogen meets acceptor carbon.
Alkali metals, Li, Na, potassium, etc. dissolve in liquid ammonia to give intense blue solutions. Liquid ammonia itself is colorless, and so are solutions of Li⁺.  The blue color comes from solvated electrons:
              Na   --------> Na⁺ [e^–]
                        NH₃
The compound is called sodium electride.  You can watch it form here

Worries About Lithium Supplies
Worries about Bolivia becoming the Saudi Arabia of lithium are overblown. First of all, the photos (see above) are deceptive: those miles and miles of white salt flats are not heaps of lithium salt: it’s mainly just dried up sodium chloride. The salts are enriched in lithium carbonates. Unlike fossil fuels, the lithium inside batteries is not destructively consumed. Lithium is not a source of energy: remember that the energy has to put back inside the batteries. We have ample domestic sources for the time being from the brines of Searles Lake, CA and in Nevada.

Last but not least, don't forget the dilithium crystals!
______________________________
¹Functional Group defined
² Redox Potential is term of art and usually refers to chemical element's potential to gain or lose an electron. In lithium, there is a high propensity for the metal to lose one electron and thus obtain the noble gas electronic configuration of helium.