Wednesday, January 31, 2007

Hopkins wanted

There are so many named things in chemistry, reactions, elements, units, equations etc etc. With some named things there is someting quite odd. The names are often well known, but that is it. I recently did a post about Dean-Stark equipment. Most synthetic chemists know the names, but only because of their apparatus. One of them was not even a chemist but a director of the 'Bureau of mines. I think it is quite weird to have a famous name but the person himself is forgotten.

I was looking for named condesers lately and managed to find out the improvers/inventor that gave it the name.

Allihn condenser - Felix Richard Allihn
Dimroth condenser - Otto Dimroth
Friedrichs condenser - Fritz Walter Paul Friedrichs
Graham condenser - Thomas D. Graham
Vigreux condenser - Henri Vigreux
Liebig condenser - Justus Baron von Liebig
Hopkins condenser - ???????????

Liebig is well known, but the other guys are not that famous. I tried to give some information about Vigreux here, but I was unable to find out who this Hopkins fellow is. So I hope I can find some publication or patent somewhere sometime...

Quick and dirty

I did a ringclosure someone else failed to accomplish. He was gone for a few days and I had to take it over. He used dry glassware and solvent and tried some microwave experiments. He had 6% yield in one case. I threw the starting materials in a flask and just heated it to melt, 92% yield. Problem solved.

When I start some new chemistry I am reluctant to think about it first. My first experiment is always the same. Throw the starting materials together with or without solvent and see what happens, if nothing happens I heat it untill the reaction goes or the starting material mutates to a black tar.

I never start the chemistry with dry/inert conditions (except ofcourse when you have a very sensible catalyst/reagent, radical reaction or something like that). Out here when people use for instance NaH they immediately use dry solvents (and have to take a walk to the basement to get it). I am lazy and just throw in some more NaH, most of the time it works just as good.

It is true. My failed reaction rate is high, mainly because I just do so many reactions. Quick and dirty chemistry takes so little time that I am able to do a lot of good things as well. Some people call me ‘the garbage alchemist’, and I see it as a compliment.

Tuesday, January 30, 2007

Top 5 Princes of Serendip

Top 5 Princes of serendip

1) Friedrich Wöhler

Trying to synthesize ammonium cyanate Wöhler made urea, proving that organic material could be synthesized from inorganic substances. Published in 1828 (Ueber künstliche Bildung des Harnstoffs; Ann. Phys. Chem. 1828, 88, 253)

2) Sir Alexander Fleming

Discovered penicillin while clearing his messy workspace. Too lazy to clean Petri dishes before going on vacation, he had the luck too look at the contaminated dishes when he got back and discovered a bacteria killing mold that had grown on the dish.

His official account of what happened is different.

Fleming A. (1929). "On the antibacterial action of cultures of a penicillium, with special reference to their use in the isolation of B. influenzæ.". Br J Exp Pathol, 1929, 10, 226

3) Albert Hofmann

Synthesized LSD in 1938 and discovered the psychedelic properties after accidental dermal absorption in 1943.

4) Sir William Perkin

The failed synthesis of quinine in 1856 produced a black tar. While clearing the glassware with ethanol he discovered that the tar contained a purple dye. Optimisation of his failed synthesis lead to a method to produce the first aniline dye mauve. He filed a patent (unable to retrieve this one) that same year (Perkin was 18 years old!) and became a wealthy man.

5) Michał Sędziwój

Discovered in the late 16th century that air contained a life-giving gas, and that this gas could be obtained by heating potassium nitrate. It would take almost two centuries untill Joseph Priestley and Carl Wilhelm Scheele found out oxygen was an element.

Thursday, January 25, 2007

Fifth Solvay International Conference

I saw this awesome video of the famous Fifth Solvay International Conference in 1927. 17 of the 29 attendees were or became Nobel Prize winners. Starring celebreties like, Erwin Schrödinger, Werner Heisenberg, Albert Einstein, Peter Debije (NOT Debye!), Wolfgang Pauli, Marie Curie, Paul Dirac, Niels Bohr and more.

Wednesday, January 24, 2007

Mr. Dean and Mr. Stark

I was complaining here that I was unable to find information about Ernest W. Dean (1888-1959) and David D. Stark (1893-??, but quite dead probably), but now I did found something.
Ind. Eng. Chem.; 1920; 12(5); 486-490.

The article gives a description of the apparatus that made their names famous in chemistry.

The article contains a (lousy) picture of a 4-unit electrically heated Dean-Stark installation that was developped for their Bureau of Mines as well.

You can read in the article that they were already aware of the marketability of their apparatus.Nowadays Dean-Stark traps are quite expensive when you buy it, so it is a profitable product... Well, all glassware is actually quite expensive.

Relatively unknown names that have the relatively most famous named-laboratory equipment.

Tuesday, January 23, 2007

Mrs. E.H. Swallow Richards

The fact that Ellen Henrietta Swallow Richards earned a place in my top 5 women chemists is not because of her scientific achievements, but because of her importance for the acceptation of women in the acedemic world in the 19th century.

She studied at the Vassar College in Poughkeepsie, New York, and obtaind a B.S. degree in 1870. She was accepted at the MIT as a student in chemistry, but was not charged tuition so MIT could say that she was not a real student. She submittet work on the analysis of iron ore to Vassar for wich she received a master's degree. She graduated in 1873 with a second B.S degree but MIT would not award her a doctorate, because they did not want to give their first doctorate in chemistry to a woman (said her husband later).

In 1875 she married MIT's mining engineering Professor Robert Hallowell Richards. She raised funds to open the Woman’s Laboratory at MIT where she worked as an assistant director. She introduced biology to MIT's curriculum and founded the oceanographic institute, known as Woods Hole.

Her first official appointment was as an instructor of sanitair chemistry. Her studies resulted in the first state water standards. She wrote more than 15 book including : The chemistry of cooking and cleaning;: A manual for housekeepers (1882). (The connection between cooking and chemistry has been a favourite topic for books and collumns again lately.)

In 1910 she finally was awarded a Ph.D. degree (honorary) by Smith College. A year later she died of a heart disease at the age of 68.

Monday, January 22, 2007

And the winner is...

Why are there so many prizes, medals and awards? Many issues of Angewandte contain the “awarded” section. (Oh no, not another Bourke Medal, Bredreck Prize, Ziegler Prize or Alfred Stock Memorial Prize!) There are in fact so many (62 admistered by ACS alone) that even I won a highly insignificant prize once for the work I did for my graduation. (The small amount of money that came with it was quite useful though.) Every industrial company, research institute, chemical society etc. etc. must have their own prize it seems.

Nowadays the CV of a respectful professor in chemistry says: “among the prof’s awards are…” and then a selection of only the 21 most important prizes. Mentioning all prizes probably takes too much space. There are so many prizes that you can have at least 4 awards a year for the rest of your life.

The fact that someone gets the Novartis prize is good for him or her, but who cares! It is just good for Novartis to have the right friends I presume. (I do not mean to say that the people do not deserve the recognition though.)

A Nobel Prize is good for your CV but the Dr. Paul Janssen Prize for Creativity in Organic Synthesis is not something that you will be remebered for next century I think.

Having a named-award is not that exclusive anymore either. People can even have one while still alive like the Corey-award, sponsored by Pfizer. (Was Corey not the guy that inspired Pfizer to develop Lipitor?)

Sunday, January 21, 2007

The preparation of paneer

The moonshine tastes great but it makes me hungry. Instant noodles do not go well with this drink. I want cheese! So I have to do some bio-experiment.

Paneer is a cheese from South-Asia that is made easily without the need of some bacterial protein coagulating agent. I just need : a cheesecloth, herbs and salt, lemon-juice, milk and a pan.
The milk is heated untill it starts to boil.
The herb are added and the milk is stirred while adding the lemon juice. Solids will appear.
The milk is left alone for 15 minutes for further curdling, yielding the curds and the colorless whey. The herbs are just for some taste, otherwise you will obtain something as tastefull as cheap mozzarella or lousy factory cheddar.
The curds are separated from the whey by filtration on the cheesecloth and. the salt is mixed with the isolated sediment.
The cheesecloth is wrapped around the curds, and then a pressure is applied to it in order to get rid of the liquid that is still in it, making the paneer less fluffy. In this case a heavy pan filled with water is left to stand on it for a few hours. Now I have the solid paneer in cheesecloth.
Unwrap the cloth and there is the endproduct.
It tastes not that bad... not great either I must admit. I will freeze it and use some of it in a salad this week. I will throw away most of it probably.

Ohhh! Nice, I still have a little high quality Stilton and some Castelmagno, that is great in combination with the instant noodles. But first: I need another drink.

Saturday, January 20, 2007

top 5 female chemists

1) Maria Skłodowska-Curie (1867-1934)

A candidate for the first place of the 'top 5 chemists' as well. Two Nobel prizes, a named-unit and a named-element.

2) Lise Meitner (1887-1968)

Worked with Otto Hahn on nuclear chemistry, but did not receive the Nobel prize (Hahn did). She has a named-element though. When I saw this picture I decided to rank her a place up again.

3) Rosalind Elsie Franklin (1920-1958)

'The dark lady of DNA', was unable to be a candidate for a Nobel prize because of her early death.

4) Ellen Swallow Richards (1842-1911)

The first woman at MIT and the first American woman to earn a degree in chemistry.

5)Maud Leonora Menten (1879-1960)

Worked on histochemistry and enzyme kinetics. Well known because of the Michaelis-Menten equation.(I was unable to find a picture of her as an old lady.)

Thursday, January 18, 2007

Confession and question

The Bunsen post was not planned. I wanted to do a 'top 5 named laboratory equipment'.


But... it turned out that it was quite difficult to obtain any biographical information about Ernest W. Dean and David D. Stark. I am not prepared to do research on them with a lot of effort (I am lazy after all).

Another top 5 list I would like to do is: top 5 women in chemistry

There are not enough women in chemistry! (Yep... it is the evidence that women are more intelligent than men.)

So, if anybody has a suggestion please comment... (Curie and Franklin already earned their positions ofcourse).

One rule: a member of a top five list must be dead! I am reluctant to write about living people.

Mr. Bunsen

His burner was mentioned in the previous post, so it will not be a surprise that this post is about:

Robert Wilhelm Bunsen (1811-1899)

The book 'Creations of fire' says about Bunsen (1811-1899):'....inventing for instance a gas burner, which is still standard laboratory equipment' (chapter 12, radical theory). Yes it is, but we do not have one. A decent lab however should have a Bunsen-burner (see previous post).

Bunsen and his friend Henry Enfield Roscoe described this Burner in the article : Photochemische Untersuchungen (Ann. Chem. Phys., 1857, 100, 43)

Bunsen and Roscoe needed a soot-free and virtually colorless burner for their photochemical measurements. The pre-mixing of gas and air in their burner was not the innovation but their design did not need a wire screen in order to prevent flashback of the flame, so they eliminated possible coloring because of contamination of the wire screen.Without the wire screen they were able to produce a more steady and hotter flame as well.

With the burner they were able to do a lot of measurements that were not possible before, and they published more than one 'Photochemische Untersuchungen'.

You will not find this kind of representations in a journal nowadays.

Wednesday, January 17, 2007

The safety-sorehead

A few months ago I needed to dry some salt, and had forgotten to put in a stove the day before. I placed the salt on a dish and used a heat gun to get rid of any water. The the fire-alarm was triggered. I was just fast enough to cancel the alarm on time. The heat gun was too hot for the alarm, but not for the drying procedure. I remebered that on our lab we had a gas burner like this:

I searched for the heat sensor of the alarm in the hood and ignited the burner as far from the sensor as possible. Within a few minutes I had my ultra-dried salt without triggering the alarm.

Sadly enough, our safety-sorehead heard the story and I was rebuked because open fire is not allowed in the lab. I knew this but we had a burner so I decided to play the unknowing idiot. I got away with it without consequences, and the reaction I wanted to with it went great.

Several years ago I worked at a lab somewhere else where the safety-sorehead was someone you never saw because he was 4 levels upstairs in a dusty office (nobody knew if the guy was even still alive). We used to dry molsieves in a flask at an oil pump and heat it with a Bunsen-burner. This was done next to the 30 litre ether distillation.

A few days ago I heard that lab is now closed because it almost burnt down completely. Safety-soreheads are not that bad after all, but I do miss a Bunsen-burner on our lab. A selfrespectful lab must have a Bunsen-burner, you do not have to use it, but you mus have it.

Tuesday, January 16, 2007

Top 5 of things this blog is lacking

A comment by Russ on this post states that I ‘may have one of the coolest chemistry blogs around.’

A subjective opnion ofcourse but this comment is making my ego so big...

In order to get back to reality:

Top 5 of things this blog is lacking

1) Pictures from the lab

I am not allowed to take pictures at the lab. Stupid industry. Others are doing this, so you have to visit, for instance, Carbon-based Curiosities (What? Oh… You came here from this site… Otherwise you should go there).

2) Mechanisms
I like mechanisms, but many other blogs are doing this probably better then I would do. At Chemical Musings, for instance, you can find mechanisms occasionally. (What? Oh… the people that did not come here from Carbon-base Curiosities came from there…)

3) Comments
That is my own fault, I do not comment a lot on other blogs and you get what you deserve. I do not ask questions in my posts, so there is not much to comment anyway.

4) European readers
About 80% of the readers are from the USA. Not so weird since most of the chemistry blogs have their origins in the USA. European readers are mainly in the UK. (I hope the visits from Romania on the Elena Ceauşescu-post is not from some intelligence agency.)

5) Posts about my work
Like number 1, everything I do is confidential all the useless things (about 80%) as well. Yep... Stupid industry.

So, I may not have the coolest blog around (a subjective opnion as well).

Monday, January 15, 2007

Mr. Schlenk

A while ago I had a post about Henri Vigreux wich is one of the most accessed posts, (first place is for the moonshine-post ofcourse).

So here is another glassware hero:

Wilhelm Johann Schlenk (1879-1943)

Schlenk had two brother who were chemists (or a sort of chemist, one was director of a brewery). Schlenk studied in Munich under Oskar Piloty the son-in-law of Adolf von Bayer. Piloty was also the brother-in-law of Ludwig Knorr (yep... keep it in the family as Carbon-based Curiosities already said.)

Schlenk worked in industry for a while and received a patent about quinoids.
Very nice how they wrote patents back then (1908). (US patent 895,689)

Schlenk had contributions in the fields of organometallic- and radical chemistry. For this work he needed to invent new techniques for working under inert atmosphere. Schlenk’s name is most remembered by the glassware he invented for this purpose. He published some glassware designs ; Mitteilungen Über Metallketyle, eine große Klasse von Verbindungen mit dreiwertigem Kohlenstoff II in Berichte der deutschen chemischen Gesellschaft, 1913, 46, 2840. The simplest design is the ‘standard’ Schlenk-tube.

The the only difference with the Schlenk tubes we use nowadays is the valve.

In this article he describes other Schlenk-glassware that I have never seen in real life.

A lot of fancy Schlenk-type glassware is still available, but I never use these things. We are not into this very delicate work here in Pharma.

A nice assay about Schlenk with further information about his life and scientific contributions can be found here in Angewandte.

Friday, January 12, 2007

Top 5 (al)chemist biographies

Top 5 (al)chemist biographies

1)Isaac Newton: The Last Sorcerer & Newton's tyranny
A shared first place about the man who filled his days with alchemical experiments and found time to discover laws of mechanics and gravitation and develop the calculus and a lot more. These books tell the story of a weird and unpleasant scientist.

2) Rosalind Franklin: The Dark Lady of DNA
The story of photo 51 and of the woman who might have been awarded the nobel prize together with Wilkins, Watson and Crick.

3) Mauve: How One Man Invented a Color That Changed the World
About the bearded chemist who became rich with the failed synthesis of quinine.

4) The Nobleman and His Housedog
A well written story about of the astronomers (and alchemists) Tycho Brahe and Johannes Keppler and how the sun ended up as the centre of our solar system.

5) Marie Curie: A Life
I like this biography more than this famous one.

Wednesday, January 10, 2007

Backfile Collections

Wiley has digitalized old journals, going back to 1832 calling them the Backfile Collections. You can read journals like Liebigs Annalen, Chemische Berichte etc (yeah I need a german dictionary).

I really like to read these things. Questionable and unhealthy synthetic procedures together with weird topics, I love it despite the german language.

I found this great example of hardcore science: Journal für Praktische Chemie, 1834, 1, 1, 127

Translation : How to treat your rifle with acid to give it a protective coating by oxidation.

I am unfortunately not allowed to carry firearms in lab, outside neither.

What I hate about patents

When I need some reference compound for a biological assay and have selected the best candidates in order to have them synthesized I always end up with synthetic procedures like this.

In this case I feel lucky I can see all intermediates, and deduct the synthetic route that was used; and : Hooray!! NMR data!!

When the patent is in English and I am searching for the endproduct I allways see general structures like this.

Seacrhing in patens for compounds and preparations is often quite frustrating.
Beneath this structure a list with so many possible substituents that about 109 different compounds is claimed.

Synthetic routes are given, but with very little procedure details. If there are details they are like this.

Just say you do not want to tell me what you did exactly right away, saves my time reading this crap!

Others just say :

Referring to procedures in a 1953 paper. You try all procedures and they all fail. After lots of experimentation you manage to improve the procedure so that it works, then you see in the latest Bioorg. Med. Chem. That they published the route with a detailed experimental section, using the things you had to find out yourself.

Monday, January 8, 2007

Top 5 of bearded chemists

In order to look like a true eccentric scientist you must have a beard and be old. To be qualified to compete for a place in this top 5 the chemists had to be bearded, dead and must have lived in the 19th century for the most of their lives.

1) Dmitri Mendeleev (it is said that he had a haircut once a year)

2) August Wilhelm von Hofmann

3) Hugo Schiff

4) Vladimir Markovnikov

5) Sir William Perkin

Thursday, January 4, 2007

130, 483, 268... BINGO!

Several publications tried to answer this question: How many drug targets are there?

The latest proposition I have seen says 324 drug targets for all approved therapeutic drugs. Others said 120, 218, 268, 273, 483 and even 14000 (revised to 6000).

268 or 273... who cares?

The 324-guys clearly say why it is useful to count drug targets.

If we are to develop predictive methods to identify potential new drug targets, it is essential that we establish with confidence the number, characteristics and biological diversity of targets of approved drugs.

I agree that if you want to find something new you must now what is old and what it is exactly you are looking for. But is it essential that we establish with confidence the number? I do not know, giving an exact number is nice for your paper however.

How come different numbers are the results of counting the same things?

They did not count exactly the same thing. Different definitions of druggable targets were used, some only counted targets of approved drugs, others counted targets of experimental drugs as well.

Can you actually establish with confidence the number? Sure... If you give a solid definition and look at what is known presently you can establish with confidence a number. I think all numbers were established with confidence at the time, the numbers are just different. All papers say what elements they want to count in wich collection and they did that, and I think they are able to do 1, 2, 3 etc.