I. Introduction to development
1806 was first proposed by J. J. Berzelius of Sweden (1779-1848) and was named as the opposite of inorganic chemistry. /kloc-At the beginning of the 9th century, many chemists thought that due to the so-called "vitality" in organisms, organic matter could only exist in organisms, and it was impossible for organic matter to be synthesized with inorganic matter in the laboratory. 1824, German chemist Willer (F.W.? Hler, 1800— 1882) was hydrolyzed with cyanogen to produce oxalic acid; 1828, he accidentally converted ammonium cyanate into urea by heating. Cyanide and ammonium cyanate are inorganic substances, while oxalic acid and urea are organic substances. Wheeler's experiment gave the "vitality" theory its first impact. After that, the successive synthesis of organic compounds such as acetic acid made the "vitality" theory gradually denied by chemists.
The history of organic chemistry can be roughly divided into three periods.
One is embryonic stage, from the beginning of 19 century to before the concept of valence bond was put forward.
During this period, many organic compounds have been separated and some derivatives have been prepared and qualitatively described. The main problem at that time was how to express the relationship between atoms in organic molecules and establish the system of organic chemistry. French chemist lavoisier (A.L. Lavoisier,1743-1794) found that carbon dioxide and water were produced after the combustion of organic matter. His work laid the foundation for the quantitative analysis of organic matter. 1830, the German chemist Justus von Liebig (1803-1873) invented the hydrocarbon analysis method. 1883, the French chemist Du Masi (J.B.A.Dumas,1800-1884) established the nitrogen analysis method. The establishment of these quantitative analysis methods of organic compounds enables chemists to obtain an experimental formula of organic compounds.
Second, in the period of classical organic chemistry, valence bond theory was established by 1858 and valence bond electron theory was introduced by 19 16.
1858, German chemist Kekule (F.A. Kekule, 1829- 1896) and others put forward the concept that carbon is tetravalent, and used the short line "-"to represent "bond" for the first time. Kekule also proposed that carbon atoms in a molecule can be combined with each other, and carbon atoms can be combined not only by single bonds, but also by double bonds or triple bonds. In addition, Kekule proposed the structure of benzene.
As early as 1848, French scientist L. Pasteur (1822- 1895) discovered the optical isomerism of tartaric acid. 1874 Dutch chemist van hoof (J.H. van tehoff,1852-191) and French chemist Lebel (J.A. Lebel,1847-60). This theory reveals the reasons for the optical isomerism of organic compounds, lays the foundation of organic stereochemistry and promotes the development of organic chemistry.
During this period, great progress has been made in determining the organic structure, reaction and classification. However, valence bond is only a concept that chemists get in practice, and the essence of valence bond has not been solved.
The third is the period of modern organic chemistry.
19 16 years, Lewis (G.N. Lewis, 1875- 1946) and others put forward the valence bond electron theory on the basis of physicists' discovery of electrons and elucidation of atomic structure. They believe that the interaction of electrons in the outer layer of atoms is the reason why atoms are bound together. If the interacting outer electrons are transferred from one atom to another, an ionic bond is formed; If two atoms use outer electrons, a valence bond will be formed. Through electron transfer or * * * utilization, the outer electrons of the interacting atoms all obtain the electron configuration of the rare gas. In this way, the "-"used to represent the valence bond in the valence bond image is actually a pair of electrons used by two atoms. The application of valence bond electron theory gives the classical image representation of valence bond a clear physical meaning.
After 1927, Hai (1904-) and others used quantum mechanics to deal with the problem of molecular structure, established the valence bond theory, and put forward the mathematical model of chemical bond. Later, milliken (R.S. Mulliken, 1896— 1986) used molecular orbital theory to deal with the molecular structure, and the results were basically consistent with those obtained by valence bond electron theory. Because the calculation is simple, many problems that could not be solved before have been solved. For complex organic molecules, it is difficult to get the exact solution of wave function. Huckel (E. Hü ckel, 1896-) created an approximate solution, which was widely used by organic chemists. In 1960s, Woodward (R.B. Woodward, 19 17- 1979) and Hoffmann (R.Hoffmann, 1937-) realized the relationship between chemical reactions and molecular orbitals, and they studied electricity. Japanese scientist Kenichi Fukui (1918-1998) also put forward the frontier orbit theory.
The main achievements of this period are substituent effect, linear free energy relationship, conformation analysis and so on.
Two. 2 1 Century Development of Organic Chemistry
2 1 century, organic chemistry is facing new development opportunities. On the one hand, with the development of organic chemistry itself and the emergence of new analytical techniques, physical methods and biological methods, human beings will have newer understanding and research means in understanding the properties, reactions and synthesis of organic compounds; On the other hand, the development of materials science and life science, as well as the new requirements of human beings for environment and energy, have put forward new topics and challenges to organic chemistry. Organic chemistry will develop in physical organic science, organic synthesis science, natural product science, metal organic science, chemical biology, organic analysis and calculation science, pesticide chemistry, medicinal chemistry, organic material chemistry and so on.
Physical organic chemistry
Physical organic chemistry is the science of studying organic chemistry with physical chemistry.
The main research and development directions are:
1. The molecular structure was characterized by modern spectrum, spectrum and microscopic techniques, and the relationship between molecular structure and properties (physics, chemistry, physiology, materials, etc.) was discussed. ) has been explored; Design and theoretical study of new molecules and materials.
2. Reaction mechanism (synergy, ion, free radical, carbene, excited state, electron transfer ...) and active intermediate.
3. Subject-object chemistry; Weak intermolecular interaction and supramolecular chemistry; Molecular assembly and recognition; Interaction and information transmission between functional macromolecules and small molecules.
4. Develop new computational chemistry methods, molecular mechanics and dynamics, and molecular design software packages; Supplement and guidance of experiment.
Organic synthetic chemistry
The science that studies the process and results from simple precursor molecules to target molecules.
Organic synthetic chemistry is the main content of organic chemistry. Since 1970s, organic synthesis has entered a new period of high development.
The basis of organic synthesis is various elementary synthesis reactions. Finding new reactions or using new reagents or techniques to improve the efficiency and selectivity of existing reactions is the main way to develop organic synthesis.
A great progress in synthetic reaction methodology is the emergence of a large number of new synthetic reagents, especially elemental organic and organometallic reagents. Due attention should also be paid to the organic synthesis reaction using physical factors such as light, electricity and sound.
Highly selective reagents and reactions are one of the most important research topics in organic synthetic chemistry, including chemical and regioselective control, stereoselectivity control and asymmetric synthesis. The latter is a field that has developed rapidly in recent years, including chiral induced asymmetric reactions in reaction substrates, asymmetric reactions of stoichiometric chiral reagents, asymmetric reactions of chiral catalysts, asymmetric synthetic reactions using organisms and new resolution methods. The conformation reflecting the reaction position of transition state is the key factor of reaction selectivity.
The total synthesis of complex organic molecules has always been the most concerned field. Reflecting the level of synthetic chemistry, combining with biological science and attaching importance to the function of molecules are the new hotspots of synthetic chemists.
The development direction of organic synthetic chemistry is: Z n &；; V & ampa+
1. New concepts, reagents, methods and reactions are applied in the synthesis methodology, and the target molecules are actually converted into high selectivity and high yield through relatively simple steps under mild conditions.
2. The (total) synthesis of molecules with unique properties (physiology, materials and theoretical interests).
3. Harmless raw materials with sustainable resources, atomic economy and environment-friendly reaction medium, process and technical route, and green and safe products.
4. The expansion of new growth points and interdisciplinary points and the application of new technologies such as chirality and bionics.
Chemical biology
Study the metabolic products of organisms and their changing rules at the molecular level; Using the method of organic chemistry to study the science of regulating the process of life system.
Chemical biology is a new discipline, which conforms to the rapid development of biology in the second half of the 20th century and is put forward on the basis of several original branches of chemistry, such as bio-organic, bio-inorganic chemistry, bio-analytical chemistry, bio-structural chemistry and natural product chemistry.
At present, chemical biology research generally includes the following parts:
1. Find substances that can regulate biological physiological processes from natural compounds and chemically synthesized molecules, and use these bioactive small molecules as probes and tools to study the mechanism of mutual recognition and information transmission between them and biological target molecules.
2. Discover the basic laws of biosynthesis in nature, thus providing new theories and technologies for synthesizing more diverse molecules.
3. Preliminary basic research on a new generation of therapeutic drugs acting on new biological targets.
4. Develop combinatorial chemistry to provide structural diversity for molecules.
5. New technologies for static and dynamic analysis of complex biological systems.
Metal organic chemistry
The science of studying the structure, synthesis, reaction and application of organometallic compounds (various types of C-M (heteroatoms)).
The main research and development directions are:
1. Metal-organic chemical elementary reaction and its mechanism: selective formation and cracking of various types of C-H (C, heteroatom).
2. Metal organic chemistry leads to synthetic chemistry and polymerization; New efficient catalysis of organometallic compounds and its application.
Medicinal chemistry and pesticide chemistry
Medicinal chemistry is an important branch of organic chemistry, which is closely related to life science. It is a science that studies the development of innovative drugs related to human diseases, health, plant protection and other life phenomena.
Development fields of medicinal chemistry:
1. Screening of biological activity by Qualcomm; Design of drug targets and molecules and combinatorial chemistry library based on structure-activity relationship.
2. Application and innovation of biochemical informatics, discovery and development of bionic and lead drugs.
3. Non-traditional mechanism of drug synthesis, analysis and function test.
Chemistry of new organic materials
The chemistry of organic materials is a science that studies and develops new molecular materials based on organic compounds. Modern science and technology
The rapid development of science and technology, especially the development of information technology, puts forward higher requirements for materials science and urgently needs to study new materials. Compared with other functional materials, molecular materials based on organic chemistry have the following characteristics: 1. There are many kinds of chemical structures, which provide people with many opportunities to discover new materials; 2. Using the theories and methods of modern synthetic chemistry, we can purposefully change the molecular structure, and carry out functional combination and integration; 3. Using the principles of assembly and mass assembly, functional molecules can be assembled at the molecular level, thus regulating the properties of materials.
The development direction of organic material chemistry is as follows:
1. Organic solids, semiconductors, superconductors, photoconductors, nonlinear optics, ferromagnets and polymer materials.
2. Synthesize molecules and orderly assembled devices with special and potential optical, electrical and magnetic functions.
3. The relationship between the structure, arrangement, combination, physical and chemical properties and mechanism of functional molecules, and the design and application of new molecular materials.
Organic separation analytical chemistry
The science that studies the separation, qualitative and quantitative analysis and structural analysis of organic matter.
Research direction:
1. Efficient analysis and identification of micro (trace) organic matter based on the progress of modern spectrum, spectrum and chromatography technology.
2. Establishment of separation and analysis methods for complex bioactive macromolecules and effective components in mixtures and environmental samples.
Green chemistry
Facing the enormous pressure of environmental protection, green chemistry has put forward some new viewpoints, the basic point of which is to fundamentally reduce or even eliminate the production of by-products by studying and improving chemical reactions and related processes, and to solve the environmental pollution problem from the source. The new and efficient chemical technology brought by the research for this purpose will also greatly improve the economic benefits. It can be seen that green chemistry is an important development direction of chemical engineering research in the century and an important guarantee for achieving sustainable development.
Development and research in this field:
1. Develop "atomic economy" reaction with high efficiency and high selectivity. Among them, catalytic asymmetric synthesis is still one of the methods to obtain single molecules. We should strengthen the research on new reactions, new technologies, new ligands and catalysts, and strengthen the research on the development and improvement of green-related biocatalytic organic reactions.
2. Develop new reactions and related processes that meet the requirements of green chemistry, reduce or avoid the use of raw materials harmful to the environment, and reduce the emission of by-products until zero emission is achieved.
3. Develop and utilize environment-friendly reaction media, including water, supercritical fluid, near-critical fluid and ionic liquid. , instead of the traditional reaction medium.
4. Utilization of reusable materials, degradable materials and biomass, and reuse of wastes in life.
In our life, organic chemistry is everywhere. Whether we can make good use of and develop organic chemistry will also affect our living standards to some extent. It is believed that with the development of scientific theory, more basic disciplines will blend with each other and play a greater role in more fields.