In the Netherlands at that time, people generally stayed in the prejudice of belittling chemistry. The father objected to his son becoming a chemist. 17 years old, graduated from Van Hof Middle School and followed his father's advice. Before going to college, he went to Delft Polytechnic Institute to study industrial technology at 1869. There, he won the esteem of chemist A.C. Oudemans and physicist Van der Sander Bakhuyren who taught in the school with excellent results, and completed the required three-year study in two years. The study during this period strengthened Van Hof's confidence and determination to engage in chemistry all his life. At home, my father's love for Byron's poems once infected their whole family. Later, Comte's positive philosophy made Van Hof bow to his knees again. All these made him learn to look at everything in life from a philosophical point of view. It also made him stand on the philosophical level to peep at the mysteries of nature all his life in chemical research.
1872, after graduating from Leiden University, Van Hof went to Berlin to study chemistry under the famous German organic chemist Kekule. The following year, Kekule recommended him to go to Woods Laboratory of Paris Medical College. Under the guidance of the famous chemist Wu Zixu, Van Hof and his French classmate Le Bell got further education. Since then, they have all become the founders of the new stereochemistry discipline. /kloc-in the middle of the 9th century, the classical structure theory of organic compounds has been basically established by Kekule and Russian chemist butler Love. But at the same time, more and more people find that some organic compounds have optical activity. The Frenchman Pasteur first discovered that tartaric acid and grape acid have left-handed and right-handed structures. Later, the German chemist Williamson Yunus also discovered the optical isomerism of lactic acid. Under the guidance of Woods, Van Hof and Le Tong Bell respectively conducted extensive experiments and explorations on why some organic compounds have optical isomerism. 1874, Van Hof and Lebel put forward the regular tetrahedron configuration theory of carbon respectively.
One day, Van Hof was sitting in the library of utrecht university, carefully reading a paper on lactic acid by Williamson Yunus. He drew the chemical formula of lactic acid on paper. When he focused on a carbon atom in the center of the molecule, he immediately thought that if all the different substituents on this carbon atom were replaced by hydrogen atoms, then this lactic acid molecule would become a methane molecule. From this, he imagined what would happen if hydrogen atoms and carbon atoms in methane molecules were arranged on the same plane? This accidental idea made Van Hoff run out of the library excitedly. While walking in the street, he thought, is it possible to arrange four hydrogen atoms and carbon atoms in methane molecules on the same plane? At this time, Van Hof, who has extensive knowledge of mathematics and physics, suddenly remembered that everything in nature tends to the state of minimum energy. This can only be achieved when hydrogen atoms are evenly distributed in the space around carbon atoms. So what do methane molecules look like in space? Van Hof suddenly realized the regular tetrahedron! Of course it should be a regular tetrahedron! This is the most suitable spatial arrangement of methane molecules. He further imagined that if the hydrogen atoms around carbon atoms are replaced by four different substituents, obviously, they may have two different spatial arrangements. Thought of here, Van Hof ran back to the library and sat down. He drew two regular tetrahedrons next to the chemical formula of lactic acid, one being a mirror image of the other. He summed up his ideas and was surprised to find that the difference of optical rotation characteristics of substances is closely related to their molecular space structure. This is the secret of optical isomerism. Van Hof believes that in the established classical organic structure theory, because people do not know the actual position of atoms, the original chemical structural formula can not reflect the isomerism of some organic compounds. Based on my own research, I published the article "Space Chemistry" in 1875. The new concept of "asymmetric carbon atom" was put forward for the first time. The existence of asymmetric carbon atoms makes tartaric acid molecules produce two variants-dextrotartaric acid and levotartaric acid; After mixing them, racemic tartaric acid with no optical activity can be obtained. Van Hof explained these optical rotation phenomena with his "regular four-body model".
Van Hof's hypothesis about the three-dimensional structure of molecules can not only explain the optical isomerism, but also explain another kind of non-optical isomerism, such as maleic acid and fumaric acid, maleic acid and fumaric acid. The birth of the hypothesis of molecular spatial structure immediately aroused great repercussions in the whole chemical field. Some knowledgeable people saw the profound meaning of the new hypothesis and praised Van Hof's pioneering work. For example, Biyi Barlow, a professor of physics at Utrecht University in the Netherlands, said, "This is an excellent hypothesis! I think it will cause changes in organic chemistry. " Professor Xianlisenus, a famous organic chemist, wrote to Van Hoff and said, "I am very happy with your theoretical research results. In your article, I not only saw an extremely witty attempt to explain the facts that have not been clarified so far, but I also believe that this attempt will have epoch-making significance in our science ... "They all actively supported and encouraged Van Hoff to translate his papers into French, German and other languages and spread them widely. However, at that time, many people did not understand the true meaning of the new theory, and they even strongly opposed Van Hoff's point of view. Professor Herman Kolber of Leipzig, Germany, wrote an article with sharp irony: "There is a doctor from Utrecht Veterinary College who is not interested in accurate chemical research. In his "Stereochemistry", he declared that he thought it most convenient to take the Pegasus he rented from the Veterinary College. When he bravely flew to the top of Pa Nacass in the field of chemistry, he discovered how atoms combine themselves in space. " However, Fitzgerald and others assert that Van Hof's hypothesis is incompatible with the laws of physics. However, these objections not only did not damage Van Hof's new theory, but also played a propaganda role in the promotion and dissemination of this theory, because people who read kolbe's sharp comments will be interested in Van Hof's theory and have to understand the contents of his paper. So, on the contrary, new theories spread rapidly in the scientific community. As Byron once said, "Once you wake up, you will be famous." Criticism of Colbert and others made Van Hoff a prominent figure. Soon, Van Hof was hired as a lecturer by the University of Amsterdam and became a chemistry professor at 1878.
Therefore, although the concept of "asymmetric carbon atom" initiated by Van Hof and the establishment of the regular tetrahedron configuration hypothesis of carbon (sometimes called Van Hof-Lebel model) have different opinions in academic circles, the subsequent practice has proved that this hypothesis has become the symbol of the birth of stereochemistry. 1878- 1896, van hoof is a professor of chemistry, a professor of mineralogy and geology at the University of Amsterdam, and the head of the Department of Chemistry. During this period, he concentrated on studying physical and chemical problems. He explored chemical thermodynamics and chemical affinity, chemical kinetics, osmotic pressure of dilute solution and related laws.
Whether a substance can react chemically and its ability to react is an ancient chemical theoretical topic. Early chemists have always used vague concepts such as "chemical affinity", "chemical force" and "acting force" to express and explain these problems. Therefore, in the early chemical literature, the concepts of chemical reaction time or reaction speed are always inseparable from the concepts of "affinity" and "chemical force". Until the beginning of 19 century, people still could not correctly distinguish the possibility of chemical reaction between substances from the actual chemical reaction speed.
So after 1877, Van Hof began to pay attention to the study of chemical kinetics and chemical affinity. 1884 published a book on chemical kinetics. In the book, he not only expounds the chemical kinetics problems such as reaction speed, but also discusses the chemical equilibrium theory and the affinity energy theory based on free energy.
This book first pays attention to the chemical reaction speed and its changing law. He creatively divided the reaction speed into three different types: monomolecular, bimolecular and multimolecular reactions. Secondly, Van Hof studied two opposite reactions (i.e. reversible reactions) from the viewpoint of chemical equilibrium. He took the lead in using double arrow symbols to show the dynamic characteristics of chemical equilibrium. Finally, he gave a clear definition of chemical affinity and studied it. In the field of physical chemistry, another topic that Van Hof pays attention to is the osmotic pressure of dilute solution and its related laws. He did many experiments on osmotic pressure of solution and put forward a universally applicable osmotic pressure formula.
PV=iRT i>。 1
Where p is the osmotic pressure of the solution and v is the volume of the solution; R is the ideal gas constant and t is the absolute temperature of the solution.
Van Hof also proved that for many substances, the value is 1, that is, the osmotic pressure relationship is PV = RT, and he also did a lot of research on the application of this formula and the system (electrolyte solution) where I is not equal. Van Hof started with chemical kinetics, and then extensively studied thermodynamics, especially the osmotic pressure of dilute solutions. He unified chemical kinetics, thermodynamics and physical determination, and laid the foundation of physical chemistry. Just as Van Hof encountered when he created stereochemistry, the birth of physical chemistry also encountered many setbacks. There is a young man in Sweden named Stefan Arrhenius, who just graduated from university. Based on the research on the conductivity of solution, he put forward the hypothesis of solution ionization. However, the emergence of this new theory was immediately strongly opposed by many domestic scholars. In order to seek understanding and support, Arrhenius sent his paper to Van Hof for revision. Unexpectedly, Van Hof, who was in a foreign country, read the paper in one breath, not only immediately grasped Arrhenius' basic views, but also was greatly inspired. His mind was suddenly enlightened: ionization! Yes, ionization! This is why the electrolyte solution I > = 1. Van Hof believes that if the electrolyte in the solution does decompose into ions, the number of particles in the solution will increase. Similarly, if the osmotic pressure is caused by particles hitting the interlayer of the semi-permeable membrane, it is easy to understand why the measured pressure is higher than the calculated pressure. He wrote his thoughts in a paper and told Arrhenius that he completely agreed with the ionization theory.
After Van Hof's article on osmotic pressure of electrolyte solution was published in Stockholm, it aroused great interest of German scientist Wilhelm Ostwald. A few months later, he made a special trip to Amsterdam and had a long talk with Van Hof. They agreed that Arrhenius' ionization theory was a great creation. Ostwald said to Van Hoff, "I think this is the beginning of a new theory, which will be the basis for studying the characteristics of solutions. And your own research will confirm and develop this theory. " He also advocated: "The cause needs everyone to cooperate more closely and unite all forces." He was very happy when he learned that Arrhenius had decided to come to Amsterdam to conduct experiments with Van Hoff, and then he would visit him in Riga. At the beginning of August, 1887, the first issue of the Journal of Physical Chemistry jointly founded by them was published in Leipzig. This marks the birth of a new frontier discipline-physical chemistry. Van Hof's friendship and cooperation with Arrhenius and ostwald enabled them to break through the limitations of national boundaries and disciplines, jointly laid the foundation for the establishment of new disciplines, and fought tenaciously for the establishment of emerging basic theories. Because of this, they are called "Three Musketeers of Physical Chemistry". Van Hof engaged in extensive research on organic stereochemistry and physical chemistry all his life, and achieved fruitful results, making him the first Nobel Prize winner in chemistry in the world. 19011210 He came to Stockholm. "He gave a speech at the grand award ceremony held by the Science College of Sweden University, and he focused on the scientific achievements in the theory of solution.
Van Hof's pioneering contributions to chemistry show that he is superior to his predecessors and contemporaries, thus winning high honors. Of course, this is inseparable from his love of chemistry since childhood and his extensive and profound knowledge in mathematics and physics. But paying attention to philosophical cultivation and constantly exploring scientific methods made him have extraordinary creative imagination. His keen interest in chemical experiments as a child later became the basis of his achievements. He attached importance to experiments, but unlike most scientists at that time, he was not confined to narrow experience. He is good at using mathematical methods skillfully to sort out experimental results, and pays attention to deducing some new theoretical introductions from mathematical equations through logical reasoning such as analogy, which is an important method for him to establish a new discipline of physical chemistry. In the process of establishing stereochemistry, it mainly reflects the profound understanding and flexible application of allosteric model method and scientific hypothesis method. He always grasps the essence of the problem from the height of philosophy and is superior.
Since 1885, Van Hof has been elected as an academician of the Royal Dutch Academy of Sciences. He was also elected as a foreign member of the Royal Academy of Cogenden, the London Chemical Society, the American Chemical Society and the German Institute, and won many honorary medals. 190 1 after winning the nobel prize in chemistry, he was invited to visit some economically and culturally developed countries such as the United States and Germany, and won honorary doctorates many times. But he never forgot to serve his country. When he encountered difficulties in scientific research, he also went abroad for research many times. However, high-paying employment and superior and comfortable living conditions abroad can keep the Dutch. Once the country has the right equipment, he will resolutely return to the motherland. He worked hard all his life with rare enthusiasm and drive. He often forgets to eat and sleep, and works more than 10 hours every day. Near the age of 60, Van Hof fell ill due to long-term overwork and was troubled by increasingly serious tuberculosis. At that time, it was an "incurable disease" that made human beings helpless, making them weaker, thinner and unable to breathe. With the help of friends, he had an operation in Berlin, but he still couldn't recover his old working ability. Stubborn Van Hof doesn't read books, organize materials and keep a diary every day, and still can't lie in bed. Feeling a little better, he couldn't lie still and asked the doctor to allow him to work. As soon as he left the hospital bed, it was as if he had forgotten his illness and was immersed in research work. Arrhenius, who had just arrived in Switzerland, immediately made a special trip to Berlin to visit his best friend. He was very sad when he saw the science swordsman suffering from disease. Arrhenius resisted his inner anxiety and still comforted his foreign comrades with fiery friendship, encouraging him to rest in peace in order to make a comeback. However, this is only a wish after all, and this meeting is actually a farewell for two great chemists. 19 1 1 March, 2008 1 day, van hoof died at the age of 59. The fall of a scientific superstar shocked the world chemical community. The Dutch people lost a loyal son. In order to remember him forever, after Van Hof's body was cremated, people put his ashes in the Dalesme cemetery in Berlin for future generations to pay tribute to.