A person must protect his home from rain and cold; your garden from pests; air from exhaust gases; water from impurities coming from harmful industries, that is, a person, living in his environment, must protect his habitat from the creation of his hands, from “himself.”
Who will save a person? Beauty?
According to scientists, there is a certain type of it that can make our existence easier.
This is the beauty of polyatomic carbon molecules called "fullerenes".
Fullerenes are unusual molecules that resemble a soccer ball in shape. Like a ball, they are hollow inside and they even wanted to call them “footballs,” but it is impossible to play football with a fullerene, since its size is 1 nanometer, that is, one billionth of a meter.
Fullerenes are the fourth, previously unknown, modification of carbon (the first three are graphite, diamond, carbon). It was discovered in 1985, quite by accident. The English chemist and astrophysicist Harold Kroto, while studying interstellar dust, became interested in the carbon particles present there. Having difficulty analyzing them, he turned for help to American colleagues Robert Curl and Richard Smalley, who were working on the evaporation of substances using a laser. All three got down to business with enthusiasm. Evaporating graphite to obtain the desired particles, they were surprised to find unknown carbon molecules in the residue, similar to a soccer ball. To Harold Kroto, the initiator of this story, the shell of the new molecule reminded the famous work of the American architect R.B. Fuller - the geodesic dome of the American pavilion at the world exhibition EXPO-67. Kroto suggested naming the new particles in honor of Fuller. This is how the word “fullerenes” appeared.
The researchers immediately sent a message about their discovery to the journal Nature.
The discovery of new molecules has generated incredible interest in their further research. A “fullerene boom” broke out, which led to the creation of nanotechnology, and with their help, to the development of previously unseen materials and compounds intended for various fields of science, technology, medicine and pharmacology.
In 1996, R. Curl, H. Croto, R. Smalley received the Nobel Prize in Chemistry for the discovery of fullerenes. Fullerenes have made a real revolution! And, although so far its results are noticeable only in science and technology, a revolution in medicine is not far off.
The revolution consists of a qualitative leap from micro..., a millionth part of a meter, to nano..., its billionth part. The prospects for obtaining new substances using nanotechnology and, of course, the emergence of nanomedicine (“nano” in translation means “dwarf”) are opening up before us. You may not yet see the word “nanomedicine” in dictionaries, but this industry has already declared its right to exist.
Small but precise:
Let us consider the properties of fullerenes from the point of view of application in medicine.
One of the most remarkable properties of these substances is that they are capable of creating aqueous solutions. By incorporating the most stable of fullerenes (called C60) into a water molecule, scientists were able to create an aqueous environment very similar to the environment in healthy body cells. Water with built-in fullerene neutralizes free radicals, that is, it is an antioxidant. Free radicals are the cause of many diseases. These molecules formed in our body damage chromosomes and lead to cell aging, cancer, and decreased immunity. They are countered by antioxidants - beneficial substances that combine with free radicals and prevent their destructive effects.
Conventional antioxidants are single-acting, one-time substances. Let's say a vitamin molecule, combining with a free radical, forms a harmless compound and is out of the game. One molecule per radical? Not too much! And the fullerene ball is long-lasting: it remains in play all the time, having the magical property of attracting free radicals. In addition, such “adherent” radicals combine with each other and form harmless substances. Thanks to the presence of fullerene, this process is incredibly accelerated, and then the unfortunate radicals drop out of the game en masse. Fullerene solutions are many times more effective than conventional antioxidants. Meanwhile, researchers say that fullerene is not a medicine in the usual sense of the word, since a medicine helps treat a specific disease, and solutions of fullerene act much more widely, throughout the entire body.
Medicine with the prefix “nano”
The possibilities of these nanoballs are truly inexhaustible and are not limited to fighting only free radicals. Fullerenes are capable of creating entire sets of bioactive compounds. By filling the cavity of the fullerene with a healing substance, you can drive this ball, like into a pocket, to the required point. Such fullerenes, jokingly called stuffed ones, can be used to deliver antibiotics, vitamins and hormones to diseased cells. Particularly persistent efforts are being made to create fullerene drugs for the treatment of brain diseases. For the first time in the world, a fullerene antioxidant for the treatment of damaged brain cells was synthesized at Tel Aviv University. Its use has yielded positive results in experiments so far with animals. Further development of this technique for the treatment of multiple sclerosis and Alzheimer's disease is expected. Experiments are being conducted with fullerenes to deliver drugs through the skin without the use of injections. Methods are being developed to destroy the genomes of viruses that penetrate a living cell using the almighty fullerenes. Work on the use of fullerenes as an antidote is promising. We can go on for a long time... Research on fullerene drugs against cancer is being conducted all over the world and the results give us hope!
It is a pity that one of their discoverers, Richard Smalley, did not live to see the final triumph of life-giving nanoballs. He passed away in 2005.
Research into healing carbon formations continues, although it has not yet gone beyond the laboratory.
Slate stone and fullerenes:
Outstanding discoveries are often surrounded by legends at first, and it seems as if they can work miracles.
In Russia, “fullerene fever” began in the late 90s of the last century. It was associated with a carbonaceous shale rock - shungite, deposits of which were discovered in Karelia.
According to one version, the Soviet geologist S. Tsipursky, having learned about the discovery of fullerenes, transferred shungite, which he brought from Karelia, for research to the laboratory of the University of Arizona in America. The results of this research, conducted with the participation of Tsipursky himself, were published in an article in a scientific journal in 1992. It said that an insignificant content of fullerenes was actually found in shungite. This became a sensation, prompting further research into shungite for medicinal purposes.
However, there have long been legends about the healing properties of shungite. This slate of an ominous black color was called slate stone in the old days. Then it received the name “shungite” - from the Karelian village of Shunga, where a spring with healing water made its way through deposits of this rock. Local old people said that shungite would heal a hundred ailments. According to legend, noblewoman Ksenia Romanova, exiled to these regions by Boris Godunov, was cured of numerous ailments here. This was the mother of the first Russian Tsar Mikhail Fedorovich. In memory of her, the miraculous spring was named “Tsarevich Key”. However, after the release of Ksenia, they forgot about him. Ksenia Romanova was the great-grandmother of Peter the Great and, probably, family legends about the healing properties of slate stone reached him. Perhaps the stone also had antiseptic properties. One way or another, there is information that Peter ordered to keep a slate stone in soldiers’ backpacks and lower it into pots of water, “in order to preserve the strength of his stomach.” The soldiers of the Swedish army, who suffered defeat in the Battle of Poltava, clearly could not preserve the “fortress of the stomach”: in the hot summer of 1709, they were pretty battered by the dysentery epidemic that broke out at that time.
Shungite rocks are used in construction and metallurgy, and recently shungite has been successfully used in filters for water purification.
In 2003, that is, ten years after the first sensational publication, an article was published in the Journal of the American Geological Society, which reported that thorough checks did not confirm the presence of fullerenes in shungite. In addition, even if they were there, the healing effect would not be created by the stone itself, but by its aqueous solution.
Organic Electronics:
Scientists at the Georgia Institute of Technology, as a result of their research, have created a matrix of high-speed field-effect transistors based on C60 fullerenes.
Professor Bernard Kippelen noted that organic semiconductors are a completely new, modern and very promising material in nanoelectronics.
The scope of application of organic nanoelectronics is huge: from displays and active electronic billboards, to RFID tags and flexible computers.
Nanocosmetics: beauty cells:
Nanotechnology is still being studied, but a whole line of cosmetic products has already appeared that use the remarkable properties of fullerenes. On the packaging of such products they usually write: “contains fullerenes” or “contains C60” (this is the most stable molecule of this group). Manufacturers claim that creams with fullerenes significantly improve the condition of mature skin, slow down the aging process, and maintain the elasticity and freshness of the face.
In conclusion:
Nanomedicine is a completely new direction in the fight against diseases. And, despite the fact that her ideas and projects are still at the stage of laboratory research, there is no doubt that the future belongs to nanomedicine.
Based on materials from www.fullwater.com.ua
"FULLEREN - THE MATRIX OF LIFE..."
So, unlike the well-known forms of carbon - diamond and graphite, fullerene is molecule, consisting of carbon atoms. The most important representative of the C60 family of fullerenes, consists of 60 carbon atoms. Indeed, we cannot say “diamond or graphite molecule,” these are just crystalline forms with a certain spatial arrangement of carbon atoms in the lattice. Fullerene is the only molecular form of carbon.
Nature has united many contradictory concepts in one object.
Fullerene is a connecting link between organic and inorganic matter. This is a molecule, a particle, and a cluster. The diameter of the C60 molecule is 1 nm, which corresponds to the dispersion boundary lying between the “true” molecular and colloidal states of substances.
If we look inside the fullerene, we will find only a void permeated with electromagnetic fields. In other words, we will see some kind of hollow space, with a diameter of about 0.4 nm, containing “ nothing" - vacuum, enclosed in a carbon shell, like in a kind of container. Moreover, the walls of this container do not allow any material particles (ions, atoms, molecules) to penetrate inside it. But the hollow space itself, as if part of the cosmos, is rather something than nothing is capable of participating in subtle, informational interactions with the external material environment. The fullerene molecule can be called a “vacuum bubble,” for which the well-known thesis that nature abhors a vacuum is not suitable. Vacuum and matter– the two foundations of the universe are harmoniously united in one molecule.
Another remarkable property of fullerenes is its interaction with water. The crystalline form is known to be insoluble in water. Many attempts to obtain aqueous solutions of fullerenes lead to the formation of colloidal or coarsely dispersed fullerene-water systems, in which the particles contain a large number of molecules in crystalline form. The preparation of aqueous molecular solutions seems impossible. And having such a solution is very important, primarily for using them in biology and medicine. Since the discovery of fullerenes, its high biological activity has been predicted. However, the generally accepted opinion about the hydrophobicity of fullerenes has directed the efforts of many scientists to create water-soluble derivatives or solubilized forms. In this case, various hydrophilic radicals are attached to the fullerene molecule or surrounded by water-soluble polymers and surfactants, thanks to which the fullerene molecules are “forced” to remain in an aqueous environment. Many studies have found their high biological activity. However, any changes in the outer carbon shell lead to a violation of the electronic structure and symmetry of the fullerene molecule, which in turn changes the specificity of its interaction with the environment. Therefore, the biological effect of artificially transformed fullerene molecules largely depends on the nature of the attached radicals and the solubilizers and impurities contained. Fullerene molecules exhibit the most striking individuality in their unmodified form and, in particular, in their molecular solutions in water.
The resulting aqueous solutions of fullerenes are stable over time (more than 2 years), have unchanged physicochemical properties and a constant composition. These solutions do not contain any toxic impurities. Ideally, it is only water and fullerene. Moreover, the fullerene is built into the natural multilayer structure of water, where the first layer of water is firmly connected to the surface of the fullerene due to donor-acceptor interactions between the oxygen of the water and acceptor centers on the surface of the fullerene.
The complex of such a large molecule with water also has a significant buffer capacity. Near its surface, a pH value of 7.2–7.6 is maintained; the same pH value is found near the surface of the membranes of the main part of healthy cells in the body. Many cell “disease” processes are accompanied by changes in the pH value near the surface of its membrane. At the same time, a sick cell not only creates uncomfortable conditions for itself, but also negatively affects its neighbors. Hydrated fullerene, being near the surface of the cell, is able to maintain its healthy pH value. This creates favorable conditions for the cell to cope with its illness on its own.
And the most remarkable property of hydrated fullerene is its ability to neutralize active radicals. The antioxidant activity of fullerene is 100–1000 times greater than the effect of known antioxidants (for example, vitamin E, dibunol, b-carotene). Moreover, hydrated fullerene does not suppress the natural level of free radicals in the body and becomes active only under conditions of increasing their concentration. And the more free radicals are formed in the body, the more actively the hydrated fullerene neutralizes them. The mechanism of the antioxidant action of fullerene is fundamentally different from the action of known antioxidants used in practice. Thus, to neutralize one radical, one molecule of a traditional antioxidant is needed. And one hydrated fullerene molecule is capable of neutralizing an unlimited number of active radicals. It is a kind of antioxidant catalyst. Moreover, the fullerene molecule itself does not participate in the reaction, but is only a structure-forming element of the water cluster. ...
At the beginning of the last century, Academician Vernadsky noticed that living matter is characterized by high symmetry. Unlike the inorganic world, many organisms have a fifth-order symmetry axis. Fullerene C60 has 6 fifth-order axes; it is the only molecule in nature with such a unique symmetry. Even before the discovery of fullerenes, the molecular structures of some proteins were known to be shaped like fullerenes; some viruses and other vital biological structures (for example) have similar structures. Interesting correspondence between the fullerene molecule and its minimal cluster secondary structure of DNA. So the size of the C60 molecule corresponds to the distance between three pairs of complementary bases in DNA, the so-called. codon which specifies the information for the formation of one amino acid of the synthesized protein. The distance between the turns of the DNA helix is 3.4 nm; the first spherical C60 cluster, consisting of 13 fullerene molecules, has the same size.
It is known that carbon, and especially graphite and amorphous carbon, have the ability to adsorb the simplest molecules on their surface, including those that could be the material for the formation of more complex biologically important molecules in the process of forming the foundations of living matter. Fullerene, due to its acceptor properties, is able to selectively interact with other molecules, and in an aqueous environment, transfer these properties to ordered layers of water at a considerable distance from its surface.
There are many theories of the origin of life from inorganic matter and their main conditions are such factors as
- Concentration of simple molecules (CO, NO, NH3, HCN, H2O, etc.) near active centers where reactions occur with the participation of external energy sources.
- Complication of formed organic molecules to polymer and primary ordered structures.
- Formation of high order structures.
- Formation of self-reproducing systems.
Experimentally, when creating the conditions that existed on earth in the prebiological period, the possibility of observing the first factor was proven. The formation of vital and unimportant amino acids and some nucleic bases under these conditions is quite possible. However, the probability of meeting all the conditions for the emergence of life is practically zero. This means there must be some other condition that allows the purposeful implementation of the mechanism of assembly of simple elements, complexity and ordering of the resulting organic compounds to the level of the appearance of living matter. And this condition, in our opinion, is the presence of a matrix. This matrix must have a constant composition, have high symmetry, interact (but not strongly) with water, create around itself a symmetrical environment of other molecules at a considerable distance, capable of concentrating active radicals near its surface and facilitating their neutralization with the formation of complex organic molecules, in at the same time, protect neutral forms from attacks by active radicals, form similar structures and similar structures of the aquatic environment. And most importantly, the matrix of carbon life must be carbon. And all these requirements are satisfied by fullerene in its hydrated state. And, most likely, the main and most stable representative of the C60 family of fullerenes. It is quite possible that the emergence of life is not a primary act, but that this process occurs continuously and somehow affects the development of life, the testing of existing life and the formation of its new forms.
Fullerenes exist in nature wherever there is carbon and high energies. They exist near carbon stars, in interstellar space, in places where lightning strikes or near volcano craters, even when gas is burned in a home gas stove. Fullerenes are also found in places where carbon rocks accumulate. A special place here belongs to Karelian shungite rocks. These rocks, containing up to 90% pure carbon, are about 2 billion years old. The nature of their origin is still not clear. One of the assumptions is the fall of a large carbon meteorite. IN shungite natural fullerenes were discovered for the first time. We also managed to extract and identify C60 fullerene in shungite.
Since the time of Peter I, there has been a healing spring in Karelia “ Marcial waters" For many years, no one could definitively explain the reason for the healing properties of this source. It was assumed that the increased iron content is the cause of the health-improving effect. However, there are many iron-containing sources on earth, but, as a rule, there is no healing effect. Only after the discovery of fullerenes in the shungite rocks through which the spring flows did the assumption arise that fullerenes are the quintessence of the therapeutic effect of the Martial waters. However, the healing properties of this water, like melt water, do not last long. It cannot be bottled and used as needed. The very next day it loses its properties. Marcial water, having passed through rock containing fullerenes and fullerene-like structures, is only “saturated” with the structure that the rock gives it. And during storage, these life-giving clusters disintegrate. Fullerene does not spontaneously enter water and, therefore, there is no structure-forming element capable of maintaining ordered clusters of water for a long time, and, consequently, such water quickly acquires the properties of ordinary water. In addition, the ions present in it themselves rearrange the native structure of water, creating their own hydration clusters.
Having once obtained molecular colloidal solutions of fullerenes in water, we tried to reproduce the essence of Martial waters in the laboratory. But to do this, they took highly purified water and added an aqueous solution of fullerenes in a homeopathic dose. After which they began to conduct biological tests on various models. The results were amazing. In almost any model of pathology, we find a positive biological effect. Experiments have been ongoing for more than 10 years. With a well-conducted experiment, any pathological changes in a living organism almost always try to return to normal. But this is not a targeted drug or a foreign chemical compound, but simply a ball of carbon dissolved in water. Moreover, one gets the impression that the hydrated fullerene tends to lead to " normal condition"all changes in the body, to those structures that it gave birth to as a matrix in the process of the origin of life.
Fullerenes in the most general sense of this concept we can call experimentally obtained and hypothetical molecules consisting exclusively of carbon atoms and having the shape of convex polyhedra. Carbon atoms are located at their vertices, and C-C bonds run along the edges.
Fullerene is a molecular form of carbon. A common definition is that fullerenes, which are in a solid state, are usually called fullerites. The crystal structure of fullerite is a periodic lattice of fullerene molecules, and in crystalline fullerite the fullerene molecules form an fcc lattice.
Since the early nineties, fullerene has been of interest for astronomy, physics, biology, chemistry, geology and other sciences. Fullerene is credited with fantastic medical properties: for example, fullerene has allegedly already begun to be used in cosmetics as an anti-aging agent in cosmetology. With the help of fullerene they are going to fight cancer, HIV and other dangerous diseases. At the same time, the novelty of these data, their lack of knowledge and the specifics of the modern information space do not yet allow one hundred percent trust in such information about fullerene.
ICM (www.site)
A widely simplified point of view is that before the discovery of fullerene, there were two polymorphic modifications of carbon - graphite and diamond, and after 1990 another allotropic form of carbon was added to them. In fact, this is not so, because the forms of existence of carbon are surprisingly diverse (see article). 
History of the discovery of fullerenes
A team of authors led by L.N. Sidorov summarized in his monograph “Fullerenes” a large number of works on this topic, although not all of them: by the time the book was published, the total number of publications devoted to fullerenes reached approximately 15 thousand. According to the authors, discovery of fullerenes- a new form of existence of carbon - one of the most common elements on our planet - is recognized as one of the most important discoveries in science of the 20th century. Despite the long-known unique ability of carbon atoms to bond into complex branched and voluminous molecular structures, which forms the basis of all organic chemistry, the possibility of forming stable framework molecules from only one carbon still turned out to be unexpected. According to the data, experimental confirmation that molecules of this type of 60 or more atoms can arise during naturally occurring processes in nature was obtained in 1985, but long before that the stability of molecules with a closed carbon sphere had already been assumed.
Detection of fullerenes is directly related to the study of the processes of sublimation and condensation of carbon.
New stage in studying fullerenes came in 1990, when a method for obtaining new compounds in gram quantities was developed and a method for isolating fullerenes in their pure form was described. After this, the most important structural and physicochemical characteristics of fullerene C60 were established. The C60 isomer (buckminsterfullerene) is the most easily formed compound among the known fullerenes. The C60 fullerene received its name in honor of the futurist architect Richard Buckminster Fuller, who created structures whose domed frame consisted of pentagons and hexagons. At the same time, during the research process, a need arose for a general name fullerenes for volumetric structures with a closed surface (carbon frame), due to their diversity.
It is also worth noting that an entire line of carbon materials is named after Buckminster Fuller: fullerene c60 (buckminster fullerene) is also called buckyball (Buckminster Fuller did not like the name “Buckminster” and preferred the shortened name “Bucky”). In addition, with the same prefix they are sometimes called: carbon nanotubes - buckytubes, egg-shaped fullerenes - buckyegg (buckyball egg), etc.
ICM (www.site)
Properties of fullerenes. Fullerite
Properties of fullerenes have not been sufficiently studied due to objective reasons: a relatively small number of laboratories have the opportunity to study these properties. But in the periodical and popular science press, so much attention is devoted to fullerenes and their properties... Often, unverified information about the miraculous properties of fullerenes spreads with amazing speed and on a huge scale, as a result, the weak voice of refutations remains unheard. For example, the statement of one group of scientists that fullerenes are present in shungite was tested repeatedly, but was not confirmed (see discussion on). Nevertheless, shungite today is considered a “natural nanotechnological fullerene-containing material” - a statement that, in my opinion, so far looks more like a marketing ploy.
Some researchers report such an alarming property of fullerenes as toxicity.
As a rule, when talking about properties of fullerenes They mean their crystalline form - fullerites.
Significant difference fullerene crystals from molecular crystals of many other organic substances in that they cannot be observed liquid phase. Perhaps this is due to the fact that the temperature is 1200 K transition to the liquid state, which is attributed to fullerite C 60, already exceeds its value at which noticeable destruction of the carbon frame of the fullerene molecules themselves occurs.
According to the data, to properties of fullerenes refers to the anomalously high stability, which is evidenced by the results of studies of processes involving fullerenes. In particular, the author notes that crystalline fullerene exists as a stable substance up to temperatures of 1000 – 1200 K, which is explained by its kinetic stability. True, this concerns the stability of the C60 fullerene molecule in an inert atmosphere of argon, and in the presence of oxygen, significant oxidation is observed already at 500 K with the formation of CO and CO 2.
The work is devoted to a comprehensive study of the electrophysical and thermodynamic properties of fullerites C60 and C70 under conditions of extreme shock loading.
In any case, when discussing the properties of fullerenes, it is necessary to specify which compound is meant - C20, C60, C70 or another; naturally, the properties of these fullerenes will be completely different.
Currently fullerenes C60, C70 and fullerene-containing products are produced and offered for sale by various foreign and domestic enterprises, therefore buy fullerenes and get busy studying the properties of fullerenes theoretically anyone can do it. Fullerenes C60 and C70 are offered at prices from $15 to $210 per gram, and more, depending on the type, degree of purity, quantity and other factors. Production and sale of fullerenes »
Fullerenes in cast irons and steels
Assuming the existence fullerenes and fullerene structures in iron-carbon alloys, then they should significantly influence the physical and mechanical properties of steels and cast irons, participating in structural and phase transformations.
ICM (www.site)
The mechanisms of crystallization of iron-carbon alloys have long been given very close attention by researchers of these processes. The article discusses possible mechanisms for the formation of spheroidal graphite in high-strength cast iron and the features of its structure taking into account fullerene nature of iron-carbon alloys. The author writes that “with the discovery of fullerenes and structures based on fullerenes, a number of works have attempted to explain the mechanism of formation of spherical graphite based on these structures.”
The work examines advances in the field of fullerene chemistry and summarizes “new ideas about the structure of iron-carbon melts.” The author states that the molecular form of carbon is C60 fullerenes- identified by him in iron-carbon alloys smelted by classical metallurgy methods, and also reveals three possible mechanisms for the appearance of fullerenes in the structure of steels and cast irons:
At one time, 5 years ago, we chose fullerene and a hexagon as the logo of the website www.site, as a symbol of the latest achievements in the field of research of iron-carbon melts, as a symbol of new developments and discoveries related to the modification of Fe-C melt - an integral stage of modern foundry and small-scale metallurgy.
Lit.:
The molecular form of carbon or its allotropic modification, fullerene, is a long series of atomic clusters C n (n > 20), which are convex closed polyhedra, built from carbon atoms and having pentagonal or hexagonal faces (there are very rare exceptions here). Carbon atoms in unsubstituted fullerenes tend to be in an sp 2 hybrid state with a coordination number of 3. In this way, a spherical conjugated unsaturated system is formed according to the theory of valence bonds.
General description
The most thermodynamically stable form of carbon under normal conditions is graphite, which looks like a stack of graphene sheets barely connected to each other: flat lattices consisting of hexagonal cells with carbon atoms at the tops. Each of them is bonded to three neighboring atoms, and the fourth valence electron forms a pi system. This means that fullerene is just such a molecular form, that is, the picture of the sp 2 hybrid state is obvious. If geometric defects are introduced into a graphene sheet, a closed structure will inevitably form. For example, such defects are five-membered cycles (pentagonal faces), which are just as common along with hexagonal ones in carbon chemistry.
Nature and technology
Obtaining fullerenes in their pure form is possible through artificial synthesis. These compounds continue to be intensively studied in different countries, establishing the conditions under which their formation occurs, and the structure of fullerenes and their properties are also being considered. The scope of their application is expanding more and more. It turned out that a significant amount of fullerenes is contained in soot, which is formed on graphite electrodes in an arc discharge. No one had seen this fact before.
When fullerenes were obtained in the laboratory, carbon molecules began to be found in nature. In Karelia they were found in samples of shungites, in India and the USA - in furulgites. Carbon molecules are also abundant and common in meteorites and sediments at the bottom, which are at least sixty-five million years old. On Earth, pure fullerenes can be formed during a lightning discharge and during the combustion of natural gas. taken over the Mediterranean Sea were studied in 2011, and it turned out that fullerene was present in all the samples taken - from Istanbul to Barcelona. The physical properties of this substance cause spontaneous formation. Also, huge quantities of it have been discovered in space - both in gaseous and solid form.
Synthesis
The first experiments in the isolation of fullerenes occurred through condensed graphite vapors, which were obtained by laser irradiation of solid graphite samples. It was possible to obtain only traces of fullerenes. It was not until 1990 that chemists Huffman, Lamb and Kretschmer developed a new method for extracting fullerenes in gram quantities. It involved burning graphite electrodes with an electric arc in a helium atmosphere and at low pressure. The anode was eroded, and soot containing fullerenes appeared on the walls of the chamber.
Next, the soot was dissolved in toluene or benzene, and grams of pure C70 and C60 molecules were released in the resulting solution. Ratio - 1:3. In addition, the solution contained two percent of heavy fullerenes of higher order. Now all that was left to do was to select the optimal parameters for evaporation - atmospheric composition, pressure, electrode diameter, current, and so on, in order to achieve the highest yield of fullerenes. They made up approximately twelve percent of the anode material itself. This is why fullerenes are so expensive.
Production
All attempts by scientific experimenters at first were in vain: productive and cheap methods for producing fullerenes were not found. Neither the combustion of hydrocarbons in a flame nor chemical synthesis led to success. The electric arc method remained the most productive, making it possible to obtain about one gram of fullerenes per hour. Mitsubishi has established industrial production by burning hydrocarbons, but their fullerenes are not pure - they contain oxygen molecules. And the mechanism of formation of this substance itself still remains unclear, because arc combustion processes are extremely unstable from a thermodynamic point of view, and this greatly hinders the consideration of the theory. The only irrefutable facts are that fullerene collects individual carbon atoms, that is, C 2 fragments. However, a clear picture of the formation of this substance has not been formed.
The high cost of fullerenes is determined not only by the low yield during combustion. Isolation, purification, separation of fullerenes of different masses from soot - all these processes are quite complex. This is especially true for the separation of the mixture into separate molecular fractions, which is carried out using liquid chromatography on columns and high pressure. At the last stage, the remaining solvent is removed from the already solid fullerene. To do this, the sample is kept under dynamic vacuum conditions at temperatures up to two hundred and fifty degrees. But the plus is that during the development of fullerene C 60 and its production in macro quantities, organic chemistry acquired an independent branch - the chemistry of fullerenes, which became incredibly popular.
Benefit
Fullerene derivatives are used in various fields of technology. Fullerene films and crystals are semiconductors that exhibit photoconductivity under optical irradiation. C60 crystals, if doped with alkali metal atoms, go into a state of superconductivity. Fullerene solutions have nonlinear optical properties, and therefore can be used as the basis for optical shutters, which are necessary for protection against intense radiation. Fullerene is also used as a catalyst for the synthesis of diamonds. Fullerenes are widely used in biology and medicine. There are three properties of these molecules at work: lipophilicity, which determines membranotropicity, electron deficiency, which gives the ability to interact with free radicals, as well as the ability to transfer their own excited state to the ordinary oxygen molecule and convert this oxygen into singlet.
Such active forms of the substance attack biomolecules: nucleic acids, proteins, lipids. Reactive oxygen species are used in photodynamic therapy to treat cancer. Photosensitizers are introduced into the patient's blood, generating reactive oxygen species - fullerenes themselves or their derivatives. The blood flow in the tumor is weaker than in healthy tissues, and therefore photosensitizers accumulate in it, and after targeted irradiation, the molecules are excited, generating reactive oxygen species. cancer cells undergo apoptosis and the tumor is destroyed. Plus, fullerenes have antioxidant properties and trap reactive oxygen species.
Fullerene reduces the activity of HIV integrase, a protein that is responsible for integrating the virus into DNA, interacting with it, changing its conformation and depriving it of its main harmful function. Some of the fullerene derivatives interact directly with DNA and interfere with the action of restictases.
More about medicine
In 2007, water-soluble fullerenes began to be used for use as antiallergic agents. The studies were carried out on human cells and blood that were exposed to fullerene derivatives - C60(NEt)x and C60(OH)x. In experiments on living organisms - mice - the results were positive.
Already now, this substance is used as a drug delivery vector, since water with fullerenes (remember the hydrophobicity of C 60) penetrates the cell membrane very easily. For example, erythropoietin, introduced directly into the blood, degrades in significant quantities, and if it is used together with fullerenes, the concentration more than doubles, and therefore it enters the cell.
Fullerenes are molecular compounds belonging to the class of allotropic modifications of carbon, having closed frame structures consisting of three coordinated carbon atoms and having 12 pentagonal and (n/2 - 10) hexagonal faces (n≥20). The peculiarity is that each pentagon is adjacent only to hexagons.
The most stable form is C 60 (buckminsterfullerene), the spherical hollow structure of which consists of 20 hexagons and 12 pentagons.
Figure 1. Structure of C 60
The C60 molecule consists of carbon atoms linked to each other by a covalent bond. This connection is due to the sharing of valence electrons of atoms. The length of the C−C bond in the pentagon is 1.43 Å, as is the length of the side of the hexagon connecting both figures, however, the side connecting the hexagons is approximately 1.39 Å.
Under certain conditions, C 60 molecules tend to be ordered in space; they are located at the nodes of the crystal lattice, in other words, fullerene forms a crystal called fullerite. In order for C 60 molecules to be systematically located in space, like their atoms, they must communicate with each other. This connection between molecules in a crystal is due to the presence of a weak van der Waals force. This phenomenon is explained by the fact that in an electrically neutral molecule the negative charge of the electrons and the positive charge of the nucleus are dispersed in space, as a result of which the molecules are able to polarize each other, in other words, they lead to a displacement in space of the centers of positive and negative charges, which causes their interaction.
Solid C60 at room temperature has a face-centered cubic lattice, the density of which is 1.68 g/cm3. At temperatures below 0° C, transformation into a cubic lattice occurs.
The enthalpy of formation of fullerene-60 is about 42.5 kJ/mol. This indicator reflects its low stability compared to graphite (0 kJ/mol) and diamond (1.67 kJ/mol). It is worth noting that as the size of the sphere increases (as the number of carbon atoms increases), the enthalpy of formation asymptotically tends to the enthalpy of graphite; this is explained by the fact that the sphere increasingly resembles a plane.
Externally, fullerenes are fine-crystalline, black, odorless powders. They are practically insoluble in water (H 2 O), ethanol (C 2 H 5 OH), acetone (C 3 H 6 O) and other polar solvents, but in benzene (C 6 H 6), toluene (C 6 H 5 − CH 3), phenyl chloride (C 6 H 5 Cl) dissolve to form red-violet colored solutions. It is worth noting that when a drop of styrene (C 8 H 8) is added to a saturated solution of C 60 in dioxane (C 4 H 8 O 2), the color of the solution immediately changes from yellow-brown to red-violet, due to the formation of a complex (solvate).
In saturated solutions of aromatic solvents, fullerenes at low temperatures form a precipitate - a crystal solvate of the form C 60 Xn, where X is benzene (C 6 H 6), toluene (C 6 H 5 -CH 3), styrene (C 8 H 8) , ferrocene (Fe(C 5 H 5) 2) and other molecules.
The enthalpy of dissolution of fullerene in most solvents is positive; with increasing temperature, solubility, as a rule, worsens.
The study of the physical and chemical properties of fullerene is a topical phenomenon, since this compound is increasingly becoming part of our lives. Currently, ideas for using fullerenes in the creation of photodetectors and optoelectronic devices, growth catalysts, diamond and diamond-like films, superconducting materials, and also as dyes for copying machines are being discussed. Fullerenes are used in the synthesis of metals and alloys with improved properties.
Fullerenes are planned to be used in the production of rechargeable batteries. The operating principle of these batteries is based on the hydrogenation reaction; they are in many ways similar to widely used nickel-based batteries, however, unlike the latter, they have the ability to store several times the specific amount of hydrogen. In addition, such batteries have higher efficiency, lighter weight, as well as environmental and sanitary safety compared to the most advanced lithium batteries in terms of these qualities. Fullerene batteries can be widely used to power personal computers and hearing aids.
Considerable attention is paid to the problem of using fullerenes in the field of medicine and pharmacology. The idea of creating anti-cancer medications based on water-soluble endohedral compounds of fullerenes with radioactive isotopes is being considered.
However, the use of fullerenes is limited by their high cost, which is due to the complexity of the synthesis of a fullerene mixture, as well as the multi-stage separation of individual components from it.
