Sciencemadness Discussion Board - How much have practical methods changes in the last century?

How much have practical methods changes in the last century?

ExothermicReaction - 2-10-2007 at 09:47

I've got a copy of Ludwig Gattermann's 1909 work, "The Practical Methods of Organic Chemistry". Is it wise to read this along with more modern books on practical methods such as Zubricks's "Survival Manual", or have there been so many updates to the basic procedures that it may do more harm than good as I try to learn solid laboratory technique?

SecretSquirrel - 2-10-2007 at 09:59

I think it's still very good idea to read Zubrick. The simple techniques haven't changed that much (by simple I mean distillation, crystallization, firltration and such). So if you want to start with organic chemistry experiments I definitely recommend it.

Slimz - 2-10-2007 at 11:52

Is that in PDF or hard copy?

JohnWW - 2-10-2007 at 11:56

PDF and/or DJVU:
The Organic Chem Lab Survival Manual - Zubrick - 2nd ed:
http://mihd.net/r09l1x

Laboratory Methods In Organic Chemistry - Gattermann (1937): http://www.sciencemadness.org/library/books/gatterman_1937.p...

See also my recent post of links for comprehensive Organic Chemistry ebooks in the References section, for more textbook and reference book downloads.

[Edited on 3-10-07 by JohnWW]

Nicodem - 2-10-2007 at 12:11

Classical methods for performing reactions have remained more or less the same. There have been some small innovations, like when doing anhydrous chemistry or similar extremes, but in general even these remained the same in essence. Some new methods of energy transfer were added in the repertoire, like microwaves, photochemistry and ultrasounds, usually with little gain in practical work - yet with exceptions.

The major changes only really became apparent in the reaction work-up procedures. The skills in this field have dramatically deteriorated during the last century. Nowadays you can actually see PhD students who never performed a vacuum distillation or are unable to do a proper recrystallization. Instead they will purify any product with column chromatography without even attempting anything else. This is inconvenient for those who would like to use the published experimental for preparing a compound as a starting material for further use (which generally requires larger amounts than just a couple of mmols). Since one can not use chromatography for larger amounts, the chemist must actually lose time by finding appropriate recrystallization conditions. This kind of attitude is also the fault of the editors and peer reviewers who, being out of touch with lab reality, favor papers reporting irrational isolated yields which can only be achieved with chromatography coupled with "rounding up the numbers." In Organic syntheses, which only publishes checked procedures, most yields are in the realistic range of 50-70% and the procedures with chromatographic separations can probably be counted by fingers (I'm aware of no such example). All the other journals are fucked up in this respect…

The analytical part is the only one that had a really tremendous progress in the last century. The new NMR, MS and XRD techniques are like gifts from the gods. The extremely tedious and years consuming old derivatization and degradation techniques are just about history. But again at the expense of not having the compounds properly characterized. It is already becoming more and more common not to report the physical properties (mp or bp) which would be the most intolerable thing to do, even some years ago. Moreover, some trivial spectroscopic data like the IR peaks are often neglected. This is why I love ACS journals. They seem to be the only ones to have highly disciplined editors.

---stop ranting already---

ExothermicReaction - 2-10-2007 at 12:46

Secret Squirrel : I assume you mean its a good idea to read Gattermann? Zubrick's 2d ed is less than 20 years old. I was particularly asking about Gattermann since it dates to 1909.

Slimz : Gattermann is also available in pdf in the library section of this site. I notice that both the original 1909 is available as well as an updated 1937 work.

The Practical Methods of Organic Chemistry (1909)
Laboratory Methods of Organic Chemistry (1937)

Nicodem : Alas, this reminds me of when I had a great love for astronomy growing up and found, to my bewilderment, that modern astronomers rarely look through telescopes! I still do. Thats the fun of it for me.

Antwain - 2-10-2007 at 13:00

For the amateur chemist very little has changed. The simpler the thing you want to accomplish the more likely it will be that same way as 100, 200 whatever years ago. I mean I expect that they could grow a decent copper sulfate crystal in the 1700s.

They didn't have quick-fit

so whenever you see a distillation, it will be easier and not require specialized glassware (in general). As you move into more advanced chemistry, stuff that was unavailable to the professional chemist of 1900 is now easy to get (but still expensive, often). I can't even think of an example, there is just too much stuff, glassware, teflon, fumehoods that WORK. And elucidation has been covered.

@ Nicodem, I think that some of the old chemistry was rubbish. I recently had to sift through papers on arsenic chem and it seems there was a boom in the 20s and 30s (probably to make CW but who knows), then some more in the 70s. Anyhow the papers from the earlier half were basically rubbish.... all of them. Different yields, mp., reactivities to air and water quoted. Fortunately I found a nice paper from '76 which detailed exactly HOW each one of these respected scientists had fucked up, as well as giving me the data I needed.

On this basis I will never trust papers from before the 50s until it is proven in my lab, mp apparatus etc. Don't get me wrong, there are still people out there publishing crap, but this stuff was so systematically incorrect it wasn't funny. Maybe thats just what I get for toiling in the obscurities of arsenic? :cool:

Nicodem - 2-10-2007 at 13:16

Indeed, a lot of the structural data and mechanistic hypotheses from before 1950's is plain wrong and one needs to consider this all the time when reading those old papers. But that is simply because they had not even the NMR and even XRD techniques were only at the beginning. The thing is, that considering the methods and knowledge they used, it is truly incredible that they got it right so often. Just check some old papers describing the complex structures of many natural products. I can't do anything else but admire their tedious work and deductive abilities to get the structures correctly determined without the modern spectroscopic techniques. It simply is amazing! Our ancestors started from point zero about 200 years ago and look what things can be achieved today.

woelen - 2-10-2007 at 14:03

I also admire what people have achieved 100 years ago or so, not only in chemistry, but also in physics and many other sciences. It really is amazing to see what they achieved, without fast computers, automated procedures, funny (but expensive) apparatus and lots of electronics.

There also is a big difference in pre-1950 books and modern books. The pre-1950 books are beautiful descriptive works, of great value for amateur chemists. I have a beautiful book of Ostwald, from 1919, "Grundlinien der Chemie". This is a book, I have read from page 1 to the end. Beautiful pictures and detailed descriptions of analytical procedures, and most important, tons of information about a lot of practical individual chemicals. The book attempts to make a systematic description, and yes, there are quite a few mistakes (such as grouping titanium with carbon, silicon, germanium and tin, based on their common +4 oxidation state and grouping the lantanides with aluminium), but the descriptive properties of the individual chemicals are good and remarkably accurate. This book has learned me lots about the reactivity of individual elements, the color of many compounds, ways of preparing compounds, et.c. It has given me familiarity with chemicals.

Also, the older books cover chemistry, which is accessible for the amateur chemist. E.g. that Ostwald-book is about inorganics, which can exist in aqueous solution, or in normal equipment with normal air inside, in temperature ranges which can be achieved in normal glass ware.

The book also covers properties of chemicals, which by now have been forgotten, and never are mentioned anymore (such as the existence of a deep yellow adduct between SO2 and iodide, just try it, add acidified sulfite to a solution of KI and see this). This kind of practical information is not present in the more modern books. They are better at explaining principles, but they also are much more terse. Tens of pages can be written about the electronic structure of some simple hypothetical molecule or ion, but what I am strongly missing is the feeling and familiarity with the real-life chemical compounds, present in the lab. I have seen chemistry books, which do not even describe common compounds like CuSO4, K2Cr2O7, KNO3 and so on, but on the other hand contains tens of pages on molecules like BF3 or radicals like CH2, OH or whatever other simple exotic mostly non-existent thing (at least under normal conditions non-existing).

Antwain - 2-10-2007 at 14:28

I second you there woelen. I love my F Sherwood Taylor. It is so wrong about so much, but if it says to make KNO3 by mixing x grams of NaNO3 with y grams of KCl in z mL of water, heat and filter, then it will be right!!!

@ nicodem, I do have respect for the pioneers, I wish I had been one of them. The stuff I am talking about was professional papers which said (I can't remember the exact wording) "After finding a beaker of methyldiphenylarsine oxide which had been sitting around the lab for 18 months I did blah blah blah".

The stuff is ****CLEARLY*** hygroscopic, we made it and left some out for a week, it forms the dihydroxyl. I would be ashamed to do stuff like that in my shed (although I admit that I have). But in a submitted paper? And several papers had stuff like this in them.

JohnWW - 2-10-2007 at 16:46

Woelen: Do you think that you could scan and upload Ostwald's "Grundlinien der Chemie" (1919), please? I would certainly like to see it.

Ostwald was a physical chemist (described as "the father of physical chemistry"); he discovered Ostwald's Dilution Law for electrolyte solutions; see http://hg.seoparts.com/dir/en.2ewikipedia.2eorg/wiki/Ostwald... and
http://en.wikipedia.org/wiki/Law_of_dilution and
http://home.arcor.de/wilhelm-ostwald/ostweng/sutton.htm and http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Ostwald-188...

[Edited on 3-10-07 by JohnWW]

SecretSquirrel - 3-10-2007 at 00:48

Quote:

Originally posted by ExothermicReaction
Secret Squirrel : I assume you mean its a good idea to read Gattermann? Zubrick's 2d ed is less than 20 years old. I was particularly asking about Gattermann since it dates to 1909.

Sorry. I thought you were asking about Zubrick. But Gatterman is still a lot of fun to read and I think the methods described therein should still work nowadays.