Adolf Lieben (December 3,1836-June 6,1914) MORITZ KOHN New York City (Translated by Ralph E. Oesper, University of Cincinnati, Ohio)
hypothesis in determining the molecular weights of chemical compounds. He clearly distinguished beThe writer studied under Lieben from 1896 to 1900 tween atom and molecule and showed how to deduce and was his assistant from then until Lieben's retire- the true atomic weights of elements from the molecular ment in 1906. The intimate friendship continued until weights of their c~mpounds.~ In 1863 Lieben was appointed vice-director of the Lieben's death in 1914. Consequently, i t seems fitting to supplement the previous paper by a rather detailed chemical laboratory a t Palerrno. Canuizzaro was his report on Lieben's achievements prior to his coming to chief. Although Lieben had had only a few lessons in Vienna in 1875. These researches have considerable Italian before coming to the Sicilian capital, he historical importance. Through them Lieben earned a quickly became so proficient that he could take over reputation as a competent worker and contributed Cannizzaro's lecture^.^ Lieben's mental capacities significantly to the founding of modern organic chem- and his linguistic talents were shown by his perfect command of English, Italian, and French; his papers, istry. Lieben attended the famous Chemical Congress a t published over a span of 55 years, were written in GerKarlsruhe (1860). He was permanently affected by man, Italian, and French. Luigi Balbiano (1852this scientific gathering a t which more than 100 of the 1917), who has given a good account of Lieben's Italian world's leading chemists were gathered together pri- period,4stated that Lieben was so fluent in these foreign marily to resolve the confusion between equivalent, languages that he actually thought in them. The atomic, and molecular weights. Two events of prime Festschrift that was presented to Lieben in honor of his importance to the development of chemistry occurred 70th birthday contains, as introduction, his reminisduring this convention. Kekul6 delivered a lecture on 1 CANNIZZARO, S., "Sketch of a Course of Chemical Philosothe constitution of organic compounds as derived from the quadrivalence of carbon. Cannizzaro addressed phy" (1858). A translation is available in the Alembic Club Reprints, No. 18, Edinburgh, Chicago, 1911. the audience on the indispensability of Avogadro's a Extracts of letters from Lieben to Csnnizzaro aregiven in the article1 discussed briefly Lieben's APREVIOUS work while he was a t the University of Vienna.
KOHN,M., "A chapter of the history of chemistry in Vienna. Adolf Liehen, 183&1914; Zdenko Hans Skraup, 1850-1910," THIS JOURNAL, 20, 471 (1943).
biographical sketch of the latter by B. L. VANzETTI, AND M. S w r s n in "Das Buch der grossen Cherniker," Berlin, 1930, Vol. 2, p. 188. BALBIANO, L., Atti. nccnd. sci. Torino.50, 7-15 (1914-15).
cences of his early years.6 He tells here of Emanuel Paternb (1847-1935), d o was his student in Palermo and later became professor in the University of Rome and also Senator. He received the boy with kindly sympathy, and their resulting friendship lasted more than 40 years. Paternb said: "Although I was fortunate enough to study under Cannizzaro, nevertheless, it was Lieben who became my first guide in scientific investigati~ns."~ Lieben was called to Turin in 1867 as successor to Rafaele Piria7 (181%1865), who had been Cannizzaro's teacher. He was received by the students in anything but cordial fashion, because they felt that worthy Italian chemists had been passed over in favor of this foreigner. However, Lieben's exemplary leadership soon won them over. When he left Turin to accept a post in his native country his departure was deeply regretted. The student body gave him heartfelt acclamations of popularity, the scientific organizations brought him honors, and the government conferred high orders upon him. The German University a t Prague called him in 1871. The plans for a new laboratory were prepared under his direction but he was called to Vienna, his native city, before the building was begun. This was left to his successor, Eduard Linnemann.* In Vienna, as in Prague, Lieben's predecessors had been Redtenbacher and Rochleder. Lieben held this chair until his retirement in 1906. His successor was Skraup. In 1859, while working in Wurtz's laboratory in Paris, Lieben prepared dichloroether by treating ether with chlorine. He assumed that each ethyl group carried one chlorine atom and accordingly named the new compound chloroether and wrote its formula, CzH,ClOCZH4Cl. In 1866 he came to the conclusion that both chlorine atoms are on one ethyl group, and henceforth he called the compound dichloroether. Since 1872, evidence furnished by Lieben and others has shown that the substance is indubitably m,p-dichloroether, CHaClCHClOCzHs. This compound made it possible (1869) for Lieben to synthesize secondary buiyl alcohol (111). B a u d working under Lieben's direction, had studied (in 18621the action of zinc ethvl on dichloroether. The & I t i n ; product, in which one chlorine had been replaced by an ethyl group, is now written CHzClCHGHs
I
and then the iodide (11), which Lieben recognized as methyl ethyl carbon iodide. The alcoholobtainedfmm this was methyl ethyl carbinol (111), since on oxidation it gave methyl ethyl ketone (IV). CHGI
CHa
CHI
CHs
CHI
CHI
CHOH
co
(1)
CeH, (11)
CmHs (111)
I I CH,
I
I I
I
I I
C& (IV)
Due to the synthesis of secondary butyl alcohol Lieben reached a further conclusion. He proved that the butyl iodide, which de Luynes had obtained six years earlier by the action of hydriodic acid on erythritol, was secondary butyl iodide, and that the alcohol, then known as butylene hydrate, and obtained by de Luynes from the iodide was secondary butyl alcohol. At Turin, Lieben persuaded a former student of Cannizzaro's, A. Rossi, to join him in an ambitious project. This was the synthesis of a long series of normal primary alcohols, aldehydes, and acids. They started with formic acid and methyl alcohol, and prepared the homologous compounds up to normal hexyr alcohol [CHa(CHz)sOH]and normal oenanthylic acid [CHs(CH~)6COOH].At first Rossi was skeptical of results. He did not believe it was possible to make a new butyl alcohol (normal primary), predicted by Kekule's theories, but thought that the known isobutyl alcohol would be obtained. When the experiment resulted as Lieben had hoped, and the synthesis of normal primary butyl alcohol was accomplished, Rossi became an enthusiastic convert to the new structure theory." The record of this series of studies is contained in 12 papers (186S77). E. Patern6 and G. Janecek collaborated in part of the work. The synthetic path used by Lieben and Rossi to go from an alcohol to the next member in the homologous series was : The alcohol (V) was converted to the iodide (VI), which was treated with potassium cyanide to obtain the nitrile (VII), and the acid (VIII) was produced by saponification. The calcium salt of the acid was mixed with calcium formate and the aldehyde (IX) resulted on heating. The primary alcohol (X)was obtained by reducing the aldehyde: RCHSOH+ RCHJ (') (VI)
OGHs (a-chloro-P-ethoxy butane). BY the action of hydriodic acid, this compound is split and then reduced. here results a hypothetical intermediate product (1)
+ RCHLN + RCHLOOH +
0'11)
(VIII) RCHsCHO + RCHCHIOH (IX) (x)
In 1856 Limpricht found that aliphatic aldehydes can be prepared by the dry distillation of the calcium salt of the corresponding acid mixed with calcium formate. P i a , independently, made the same discovery 6 "Festschrift Adolf Liehen zur Feier des siehzigsten Gehurtstages und des goldenen Doktorjubil&ms, geiwdmet von Freun- with respect to the formation of aromatic aldehydes den, Schiilem und Verehrern." Verlag von Winter in Heidelberg. in the same year. Wurtz showed that aldehydes can be 1906. BARGBLLINI, G.,Obituary sketch of Patemb, Bcr., 68, 47 reduced to the corresponding alcohols. Limpricht himself did not expect much from his method, and (1935). 7 Discovered salicylic acid in 1838. stated explicitly that it was not likely to be of practical A pupil of KekulL and f m e r l y professor at Lemberg and Bfinn. 'Alexander Bauer (183G1921). later professor at the Polytechnikum in Vienna.
The term "structure" was intmducedby A. Butlerow (1828. lo
1886). professor in Kasan and St. Petershurg. Liehen "Festschrift," p. 15; see fwtnote 5.
use because of the considerable quantities of t a n y byproducts. In 1867 Siersch, a t Linnemann's suggestion, tried out the procedure and concluded it was not adaptable to the preparation of propionaldehyde. Nevertheless, Lieben and Rossi found the method of Limpricht and Piria to be usable and showed that no rearrangements occur in the reaction series, V to X. Wurtz isolated "fermentation" butyl alcohol from fuse1 oil in 1852, and in 1867 Erlenmeyer showed that this alcohol (XI) yielded isobutyric acid (XII) when oxidized. Consequently i t is primary isobutyl alcohol. Butlerow prepared tertiary butyl alcohol (XIII) in 1864 by the action of zinc methyl on acetyl chloride. In 1869, as stated above, Lieben synthesized the secondary normal butyl alcohol (111). Accordingly, three of the four isomers predicted by theory were known. Lieben and Rossi prepared the missing isomer, normal primary butyl alcohol (XIV), in 1869.
show that this reaction is a very sensitive test for ethyl alcohol and, furthermore, that acetaldehyde, as well as all substances containing the groups CHaCOCt or CHaCHOHCf, react with iodine in the presence of alkali hydroxide to yield iodoform. While Lieben was in the midst of this study of the iodoform reaction, Liebig, Wohler, and Buff, who were on a vacation tour, dropped into the laboratory a t Turin. Lieben told them of his current experiments and Liebig, sensing the significance of this iodoform reaction, asked Lieben to publish his results in the Annalen. The invitation was accepted.I2 The iodoform test was destined to become extremely important and widely applied. Ten years after Lieben's paper, G. Kramer employed it in the analysis of technical methyl alcohol. Since Lieben had shown that pure methyl alcohol does not give this reaction i t is possible in this way to determine quantitatively the acetone present as an impurity in methanol. The iodoform reaction $!H8 later gave rise to the masterly study of chelidonic acid by Lieben and Haitinger, because the former had been struck by the intense response of chelidonic acid to this test.la Lieben was conservative in the matter of publication. His axiom was to publish only that which had passed Their starting material was normal butyric acid his own severest tests, and which in all likelihood would ("fermentation" butyric acid). The calcium salt, dry hold up against attacks by future workers. For the distilled with calcium formate, yielded normal most part, he preferred that his collaborators publish butyraldehyde, which was then reduced to the normal under their own names, with no mention of his participrimary alcohol. The latter was converted into nor- pation. In a previous paper of this series, Skraup was said to mal valeric acid and this was used to produce normal be Rochleder's pupil. Although this is correct, yet he amyl alcohol. In the course of these studies it was found that normal capronic acid, CH3(CHz)&OOH, is was also Lieben's pupil. When Liehen was called to identical with the fermentation acid. The synthesis of Vienna as Rochleder's successor, he suggested that normal oenanthylic acid was by way of the normal hexyl Skraup, who had been Rochleder's assistant, work on the iron cyano compounds. The two papers by Skraup alcohol. Linnemann was working on the synthesis of alcohols on this topic clearly reveal Lieben's influence and couna t this same time. He made unwarranted attacks on sel. Lieben's accomplishments were freely acknowledged Lieben's findings and the latter published a short paper : "In defense." As Linnemann had made no mention of and lauded by the chemical world. At the early age of Lieben and Rossi, Lieben stated caustically: "I can 34 he was elected to the Vienna Academy. Similar explain this peculiar omission only through the writer's elections came from Rome, Turin, and Munich. He fear that he would immortalize our names if he included was vice-president of the German Chemical Society in 1884. The London Chemical Society and the Societe them in his paper." In 1873 Lieben and Paternb reported that the dry Chimique de France conferred honorary membership distillation of calcium formate yielded methyl alcohol, upon h i . The French Academy awarded him its the reduction product of formaldehyde. But formalde- Lavoisier and Berthelot medals. After Lieben's retirement, the Emperor Franz Josef made him a member of hyde itself was not produced by this reaction." During his studies of the preparation of alcohols from the Austrian upper chamber, which corresponded to dichloroether Lieben found (1868) that organic chlo- the British peerage. In closing his recollections of his early years14Lieben rides are converted to the corresponding iodides by the action of hydriodic acid. Thus, in a concentrated said: "My concept of the task of science, whose service solution of HI, iodine is substituted for chlorine in ben- I entered more than a half century ago, has remained zyl chloride in three weeks at room temperature (1869). unchanged: to search for the truth regardless of perDuring his work on secondary butyl alcohol Lieben sonal profits and general preconceptions. I believe I treated ethyl alcoholic solutions of iodine with potas- can truthfully say that I have sought this goal honestly and unswervingly." sium hydroxide, producing iodoform. This was not a new observation, since this method of making iodoform "LIEBEN,A.. Ann. Suppl.. 7 , 218 (1870). had been used by Serullas in 1832. But Lieben did laKOHN, M.. THISJOURNAL.. 20, 471 (1943). " "Festschrift," p. 20; see footnote 5. T E B E NA,, , AND E. PATERN& Ann., 167,293 (1873).
