Michael, Arthur

Arthur Michael was born on August 7, 1853 in Buffalo, New York, into a wealthy family of Clara (nee Pinner) and John Michael. He studied at the Briggs school in Buffalo, where at that time there were no chemistry lessons, but Michael managed to get basic skills in this subject from a local teacher, he conducted experiments in a home laboratory equipped with his father ^[3] .

Due to a serious illness, Michael, planning to enter Harvard, went on a long trip to Europe with his family in the summer of 1871, deciding to stay in Germany. Despite a very modest training in chemistry, Michael managed to get a job in the chemical laboratory of Professor A.V. Hoffmann at the University of Berlin . A year later, Michael moved to Heidelberg , where for two years he studied under the guidance of R.V. Bunsen . Returning to Berlin in 1876, Michael over the next two years performed and published an extensive series of brilliant and important studies ^{[4] [5]} . Michael completed his education in 1879-1880 in the Paris École de Médecine under the leadership of C. A. Würz ^[6] .

Returning to the United States in 1880, Michael became a professor of chemistry at Tufts College , where he taught in 1882–1889. There Michael met Helen Abbott , who was one of his students, and in 1888 married her. After several years in England, where the couple worked in a personal laboratory on the Isle of Wight , they returned to the United States in 1894, where Michael again taught at Tufts, leaving him in 1907 with the title of professor emeritus.

In 1912, Arthur Michael received the status of professor of organic chemistry at Harvard , here he had the opportunity not to give lecture courses, but only worked in a laboratory at the Newton Center, had personal assistants and graduate students. In 1936, Arthur Michael received the title of Honorary Professor at Harvard ^[7] .

Arthur Michael died on February 8, 1942, in Orlando, Florida, in his 89th year of life. His wife died in 1904 from the flu. ^[8] They had no children.

Pilot studies

In 1879, Michael the first managed to obtain the glycoside chelicide ^[9] , the synthesis of which began to be used to obtain substances of this class of compounds. In 1887, he discovered the possibility of addition of reactants with an active methylene group to α, β-unsaturated esters and carbonyl compounds, which was later called the Michael reaction ^[10] . In 1900, Michael discovered chlorine dioxide ^[11] .

Contribution to Theoretical Chemistry

Reflecting on the origin of chemical elements, Michael adhered to the ideas of chemical evolution, according to which the elements appeared in a sequential order depending on the amount of free energy stored in the atom.

When considering the chemical reaction, Michael was guided by the idea of F. A. Kekule , considering the first step in the process the collision of two molecules attracted to each other due to their chemical affinity, with the formation of a double molecule, the stability of which is determined by the degree of conversion of the free chemical energy of two different molecules into binding energy and warm.

Michael was also well known for his work on the application of thermodynamics to organic chemistry ^[12] . He rephrased the second law of thermodynamics , talking about the increase in entropy that took place in every spontaneous chemical reaction, as a "chemical neutralization", meaning by this neutralization of the free energy of reacting atoms. According to his theory, the magnitude of chemical neutralization directly depends on the magnitude of the conversion of free energy into binding energy ^[13] . His theory explained molecular rearrangements, addition and substitution reactions ^[14] , tautomerism and stereochemistry of processes ^[15] .

Many of Michael's works are devoted to asymmetric connection, the direction of which is explained by the “+ \ -” rule formulated by him. According to it, maximum neutralization is achieved by attaching an electronegative atom or group to a more electropositive atom of an unsaturated molecule and vice versa. The “+ \ -” rule was confirmed in the synthesis of malonic and acetoacetic esters ^[16] . Moreover, the formation of a specific product depends on the chemical affinity of the atoms. This is the “principle of distribution” proposed by Michael.

Criticism of Accepted Opinion

Another important contribution, perhaps, along with his thermodynamic theory in its direct influence on organic chemistry, was the role of Arthur Michael as a critic.

So he refused to accept the works of J. Wislicenus on the theory of geometrical isomerism of Van Hoff , which, in his opinion, was an unproven hypothesis, since it was based purely on mechanisms and geometry, and not on thermodynamic factors. He refuted the assertion that addition to unsaturated molecules necessarily takes place in the cis direction and proved this in a series of experiments in which trans-addition dominated ^[17] .

In 1889, Michael was able to prove the reactivity of methylene groups in β-sulfonyl esters, thereby refuting the accepted views of Victor Meyer that the sulfonic group cannot be compared with the carbonyl. In 1920, following his theory of affinity and energy, he studied the mechanisms of pinacon and benzoin rearrangements ^[18] , and came to the conclusion that the accepted interpretation of M. Tiffno is chemically impossible.

A description of the cyclization processes according to the stress hypothesis of A. Bayer did not consider either chemical affinity and energy relations, nor the influence of side groups, and as a result was not convincing for Michael. So, Am managed to get a compound with a four-membered ring through the interaction of ethyl sodium malonate with ethyl citraconate, thereby proving that in the presence of certain side groups, cyclobutyl derivatives are just as easily formed as any derivatives of five- or six-membered rings.

Michael's results proved the need to combine thermodynamic principles with structural theory, to identify a close relationship between energy relations and chemical behavior, which ultimately led to a deeper understanding of organic chemistry and the development of a general theory of organic reactions.

One of Michael's main interests was ancient and medieval art , he had a collection of early American silver, which he bequeathed to the Smithsonian Institution , and the rest of his collection, among which there were many items from the east, at the Albright Art Gallery in Buffalo.

In his youth, Arthur Michael was fond of mountaineering and often spent vacations in the mountains ^[3] .

Michael is remembered as an energetic, agile, but at the same time shy person, deeply immersed in his scientific and artistic pursuits. He avoided publicity. As a teacher, he knew how to stimulate and inspire, strove for thoroughness and accuracy. Michael was very fond of children, but never had his own. Therefore, he bequeathed the remainder of his significant property to three institutions in Buffalo to care for disabled, blind and needy children ^[3] .

• Professor Emeritus, Tufts College (1907)
• Professor Emeritus, Harvard University (1936)

• Brief biography and a photograph