MOLINA Mario( Chemist, Nobel Prize in Chemistry, 1995)
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Biography MOLINA Mario
MOLINA, MARIO (Molina, Mario) (p. 1943) (USA). Nobel Prize in Chemistry, 1995 (with P. Krutsenom and S. F. Rowland).
Born in Mexico City March 19, 1943. Father - Roberto Molina Paskuel, a lawyer and teacher, and in the future, the Mexican Ambassador to Ethiopia, Australia and the Philippines, the mother - Lenore Henrico de Molina. In Mexico City, he graduated from high school. At age 11, parents were sent to a boarding school in Switzerland. In 1960 joined the National University of Mexico State, in addition listened mathematical lecture courses.
Molina then went to Germany and enrolled at the University of Freiburg, where he studied the kinetics of polymerization. After two years he spent several months in Paris, . where the self-study mathematics, . then in Mexico City he became an assistant at the University, . and, . Finally, . in 1968 went to the University of California at Berkeley to perform post-graduate work in physical chemistry,
At Berkeley, joined the group of Professor George P. Pimentel (George C. Pimentel) for the study of molecular dynamics with the help of chemical lasers. Pimental was a pioneer in studying the properties of unstable substances. One of the first scientific successes Molina was an explanation of some laser signals, as 'relaxation oscillations', which could be predicted from the equations of laser emission. In 1972 he completed his thesis and left for another year to continue work on chemical dynamics.
Autumn 1973, he joined the group of Professor F. Sherwood Rowland in Irvine, California. Rowland has been a leader in research chemistry 'hot atoms'. He asked Molina to find out what happens in the environment and inert industrial chemicals - chlorofluorocarbons (Freon), which accumulate in the atmosphere. At that time it was thought that they did not have a significant impact on the environment.
Three months later, Molina and Rowland developed the theory of reduction of the ozone layer in the presence of freon. Basic provisions can be formulated as follows: freon - man-made components, which flow in the lower atmosphere (troposphere) is approximately equal to their industrial production.
Being extremely chemically stable in the troposphere, freon are very 'lifetime' (40-150 years). The only way to remove them from the troposphere is the slow transfer to the stratosphere.
In the stratosphere, they are photolysed shortwave UV radiation of the sun, releasing chlorine atoms.
Chlorine atoms attack the ozone molecules, destroying them and giving SlO chlorine oxide, which interacts with atomic oxygen, resulting in the newly formed Active chlorine - an important component of the cycle of ozone destruction.
Following their publication have been numerous attempts of mathematical modeling of the stratospheric ozone loss in the various 'scenarios' production of CFCs. It turns out that more or less realistic models require consideration of not less than 150 reactions involving about 50 different particles, since the chlorine atoms react not only with ozone, but also with molecules of water, methane, nitrogen oxides, etc..
The ozone problem is closely related to important economic factors, and its solution required the adoption of international political decisions directly affecting the vital interests of many millions of people. These decisions were taken in conditions far from complete and rather contradictory information about the changes occurring in the stratosphere. We can not accurately assess the role of such action, . because their results will appear in a long time, . but, . whatever, . they remain in the memory of mankind as the first in its history, large-scale agreement, . aimed at preventing disruption in the world of chemical equilibria,
Restriction and, ultimately, a ban on the production and use ftorhloruglerodov led to the search for less hazardous substitutes. Because the substitutes are not completely safe for the ozone layer, their use is not fully solve the problem of stratospheric ozone. Meanwhile, it was shown that the freon has always acted and continue to flow into the atmosphere from the deep layers of the lithosphere as in the areas of volcanic activity, and on countless faults.
Regardless of anything, these studies have stimulated the development of such relatively new scientific disciplines such as environmental chemistry and atmospheric chemistry.
In 1975, Molina became a permanent employee of the University of California at Irvine and began his own program of study of chemical and spectroscopic properties of compounds relevant to the atmosphere. Particular attention was paid to those compounds that are unstable and are difficult to deal with in vitro.
In 1982, Molina moved to the Department of Molecular Physics and Chemistry of the Jet Propulsion Laboratory California Institute of Technology, where he organized a small pilot group. The transition was caused by a desire to devote himself to research work
. In 1985, when he heard about the opening of the seasonal ozone depletion over Antarctica ((Joseph Farman), Molina took part in the effort to study the chemistry of the atmosphere created by polar stratospheric clouds, part of which consists of ice crystals
. This work was carried out with the use of aircraft. He was able to show that in the polar stratospheric chlorine activation reaction in the presence of ice flow is very effective, scientists have modeled the impact of clouds on the Antarctic atmospheric chemistry in the laboratory. To understand the rapid catalytic reactions over the South Pole, experiments were conducted with peroxide, chlorine, a new substance, which until then had no data in the literature. This was important to explain the loss of ozone in the polar stratosphere.
In 1989, Molina returned to teaching, having started work at MIT, where he continued to develop research release of chemicals in the Earth's atmosphere.
In 1995 he was awarded the Nobel Prize which he shared with his former manager C. Rowland and P. Krutsenom Dutchman 'for their work in atmospheric chemistry, particularly in connection with the formation and ozone depletion'.
Molina is married, his wife, Luisa Molina, engaged in environmental chemistry and has participated in many scientific studies of her husband. The family lives in Lexington, Massachusetts.