Chemistry, by way of a more or less "popular" definition, can be described as a science of transformations of substances and ways of managing, or controlling these processes. This area of research is believed to have taken its start back in the 18th century, when it was only inorganic chemistry, and it went into full bloom in the 19th century with the advent of organic chemistry and classical thermodynamics (subdivision of physical chemistry). As for the 20th century, it was dominated, so to speak, by physical chemistry (in its full volume), technical chemistry (also called chemical technology) and biochemistry A leading expert in the field-Academician Valentin Parmon, Chairman of the Joint Learned Council on Chemical Sciences of the Siberian Branch of the Russian Academy, has shared his views on the achievements of this nearly all-embracing science and its future prospects.
It was back in prehistoric times that Homo sapiens became acquainted with the first chemical reaction-fire. Ever since chemistry has continued to develop and lavishly "shared" its knowledge with most, if not all, areas of human endeavor. This knowledge is now successfully applied in power engineering (combustion management in thermal machines, etc.), mechanics (concerning the development of structural materials and also providing the basis for thermal engines and their fuels), in nuclear power engineering (nuclear reactions and fissile chemical elements). Geochemistry has been fully submitted to geology, and biology has been "blessed" with the now rapidly progressing biochemistry
But the central achievement of fundamental chemistry at the start of the 20th century was unravelling the phenomenon of radioactivity which made it possible to "bridle" nuclear energy. At the same time a clear picture was obtained of the structure of matter-the molecule and the chemical bonds therein. Studies of molecules led to the advent of quantum chemistry and chemical kinetics (science of the rates of chemical reactions), which took shape in the late 19th century, promoted the progress of the theory of branched chain processes discovered by Academician Nikolai Semyonov (1896-1986) in the early 1930s. For this discovery the Russian scientist and Ms British colleague Sir Cyril Hinshelwood (1897-1967) were honoured with a Nobel Prize in 1956. The most significant results of research in this field was the development of the A-bomb and the controlled conduct of, first, nuclear and later thermonuclear explosions. What is more, the development of chemical kinetics led to the birth of what we call the activated complex theory which makes it possible to prognosticate the behavior of a specific substance in various reactions.
Another area of this science-physical chemistry-had an important role to play in the development of a new field of research-thermodynamics of non- equilibrium processes. Russian researchers provided a tangible contribution to its establishment. In the early 1950s, for example, V. Belousov discovered the first oscillating (altering the color of solution) time-dependent chemical reactions which had been previously regarded as impossible in principle.
The 20th century witnessed torrential progress in analytical chemistry: scientists developed the main types of the now state-of-the-art instruments for determining the composition of complex mixtures - the chromatographs. And it is interesting to note that the basic principle of their operation rests on the ideas of the Russian physiologist and biochemist, Mikhail Tsvet (1872-1919). Firmly established among research techniques used to investigate the surface of materials is tunnel microscopy * which makes it possible not only to "visualize" atoms, but manipulate them as well. Finally, there came one of the latest achievements of physical chemistry - femtosecond spectroscopy, capable of achieving temporal resolutions of down to 10 -15 sin which time light can cover a distance of only fractions of a micron. With the help of this method scientists can investigate the movements of individual atoms within reacting molecules.
Considerable achievements of fundamental chemistry have also been observed in the field of directional or controlled, fine organic synthesis. Thanks to that specialists can now "engineer" practically any substances with preset parameters (including biologically active ones). This is also promoted by the fact that the chemical analysis theory has now taken body and form.
One of the important achievements of chemists in the 20th century was the emergence of biochemistry as a science in its own right. And a number of
* See: V. Bykov, "Microscope Scans Atoms", Science in Russia, No. 4, 2000 . - Ed.
fundamental problems have been resolved within its framework. One of them has been the development of the theory of heredity which, in its turn, prepared the ground for the biology of genes and genetic engineering. Biochemistry has also made significant progress in determining the characteristics of the apparatus of natural photosynthesis which ensures the existence of life on this planet.
From among the latest fundamental works of chemical scientists (mid-1980s) one should mention high-temperature superconductivity.
Significant progress has also been made in the development of applied chemistry. Specialists in this field developed a method of in-depth processing of oil, with the pioneering role in these studies belonging to a Russian researcher-Academician Vladimir Ipatyev (1867-1952). He was the first to suggest the idea of conducting industrial processing of oil at great depths with the help of catalytic technologies. In the 1940s Academician Ipatyev pioneered a method of production of high-octane benzines.
The 20th century saw the birth and development of new areas of chemical research-the chemistry of transuranium elements and radiochemistry. Physicists and chemical scientists mastered the technologies of isotope separation of most different chemical elements which made it possible to obtain plutonium, separate uranium-235 and, in the final analysis, build a stable raw material base for controlled nuclear reactions which ushered in the epoch of nuclear power engineering.
The list of achievements scored by chemical scientists in the 20th century obviously includes polymer structural materials. This covers practically all of the plastics in current use, like polyethylene, polypropylene, polyurethane, nylon, polyesters, and the like.
Chemical scientists deserve much credit for the development of new and highly effective medicinal preparations, for pioneering the hitherto unknown methods of protecting the environment from the steadily mounting technogenic pressures and for the production of super-pure substances (germanium, silicon, gallium) which are the basis of micro- and nanoelectronics.
As for the prospects of development of the chemical science in the new century, Academician Parmon sums up his views in the following way:
The central problem of modem-day chemistry consists in the unbelievably large store of concrete knowledge which keeps growing at a faster pace than in other areas of research and is running ahead of the experts' potential for the assimilation of this knowledge. This being so, an urgent task for the near future is to try and systematize the basic elements of the acquired data. And there is also the growing role of computer chemistry which prognosticates the likely results of a newly developed process. Today scientists have at their disposal enough information in order to "replace" the laborious test-tube experiments with computer simulation to help them to decide whether or not a costly experiment is really worth the effort.
Rapid progress is lying in store for the chemistry of nanomaterials where the size of the particles obtained amounts to only tens of angstroms. This includes most of the heterogenous (consisting of microscopically non- homogeneous parts) catalysts which are of great importance for the control of chemical reactions. This area also includes supramolecular chemistry which investigates the organization of major molecular structures (often of polymeric kind) into orderly "tertiary" ones. Specialists are to develop such systems artificially; the "super task" here is to design molecular electronics which can progress only on the basis of nano- and supramolecular chemistry
One of the perennial arguments among the scientific community concerns the problem of the origin of life from dead matter. A problem of such importance cannot be attacked without first having a very clear physical and chemical definition of the phenomenon in question. In Academician Parmon's view the future formula of this kind must include these words: "Life is a form of existence of a catalyst, which...". This idea rests on the confidence that life really represents the functioning of a special type of biocatalysts. This being so, it is essentially important for fundamental chemical science to develop artificial systems which can reproduce natural photosynthesis.
Great problems are also in store for applied research. This includes, above all, developing well-controlled methods of synthesis of biologically and physiologically active substances. Specialists know full well that optical isomers (substances absolutely identical in composition and even primary structure) can have a different biological impact. But getting them in pure form is quite problematic.
Another likely event in the not too distant future will concern a substitution of the raw material base not only in modem power engineering, but in the chemical industry as a whole. Until today this base was oil and petroleum- processing products, and these will soon be replaced with natural gas and methane. Emphasis will also be on the development of the large-scale chemistry of renewable raws, above all biological ones (wood, agricultural wastes, etc.).
Academician Parmon also anticipates a revolutionary event for the whole of our terrestrial civilization - a transition to nontraditional (alternative) kinds of energy and energy carriers. In this connection hydrogen will assert itself within a short span of time as a universal and ecologically clean energy carrier.
Facing scientists in the new millennium are also some more specific problems of applied chemistry Thus no broad use has been made so far of coherent laser emissions. A major breakthrough is approaching in the chemistry of silicon and other semiconductors.
The 21st century will set very high standards on chemical research which is one of the basic areas in our cognition of the world and in securing a worthy life for the whole of humanity.
Nauka v Sibiri (Science in Siberia), 2000
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