BackgroundBefore the early 60s. XX century it was generally accepted that
There are only two forms of crystalline carbon - diamond
and graphite, widely distributed in nature and known
to humanity since ancient times. Many researchers
expressed bewilderment and considered it somewhat illogical that
existence of the element with the richest chemistry
limited to only two allotropic modifications.

Background

Diamond is a three-dimensional (spatial) form of carbon - formed
carbon atoms in the state of sp3 hybridization (Fig. 1, a). In graphite
– two-dimensional (planar) form – all carbon atoms are in
state of sp2 hybridization (Fig. 1, b). It was natural
assume that there must be another allotrope
carbon form – chain (linear) – with sp-hybridized
carbon atom (Fig. 1, c). This problem has long attracted
attention of scientists - both theorists and practitioners.

Bayer's experience

In 1885, the German chemist A. Bayer
tried to synthesize chain
carbon from acetylene derivatives
stepwise method. However
Bayer's attempt to obtain polyine
was unsuccessful, he received
hydrocarbon consisting of four
acetylene molecules connected in
chain, and turned out to be
extremely unstable.
Work in this direction will last for a long time
stopped.

Discovery of the carbine

In 1959–1960 in the laboratory
high molecular weight compounds INEOS,
headed by Academician Korshak,
systematic studies have been carried out
oxidative coupling reactions
diacetylene compounds. Was
It was found that in the presence of salts
divalent copper this reaction can be
carried out with any diacetylene
compounds to form polymers,
the elementary link of which preserves
carbon skeleton of the original diacetylene.
In this case, polymers are first formed
Cu(I) polyacetylenides. This option
oxidative coupling reactions were
called oxidative
dehydropolycondensation.
V.V. Korshak

Discovery of the carbine

Scientists have suggested that as a monomer for such
For polycondensation, you can also take acetylene. Indeed, when
passing acetylene into an aqueous ammonia solution of Cu(II) salt
A black precipitate quickly formed. It was this path that led
A.M.Sladkova, V.V.Korshak, V.I.Kasatochkina and Yu.P.Kudryavtsev
(photo) to the discovery of the linear form of carbon, which they, according to
Sladkov’s proposal, they called it “carbine”* (from
lat. carboneum (carbon) with the ending “in”, adopted in
organic chemistry to denote acetylene bond).
From left to right:
V.V. Korshak,
A.M.Sladkov,
Yu.P. Kudryavtsev,
V.I.Kasatochkin

The structure of carbine

According to the discoverers of carbine, the most difficult thing was
determine what connections are connected in a chain
C
C
C
C
C
C
C
carbon atoms
,
,
C
n
or double and triple bonds simultaneously.
A few years later it was possible to prove that in double carbine
no connections. Confirmation of the polyine structure of the chains
education served oxalic acid during ozonation
carbine:
n
C
C
O3
C
C
H2O
O
O
O
n
C
HO
n
O
n
O
C
OH

Oxidative dehydropolycondensation of acetylene

The first method for obtaining carbyne is oxidative
dehydropolycondensation of acetylene. Acetylene was passed through
aqueous ammonia solution of Cu(II) salt, a rapid
formation of a black powdery precipitate,
copper polyacetylenides. When dry, this powder
exploded when heated, and when wet - when detonated.
Schematic diagram of the process of oxidative dehydropolycondensation
acetylene can be written in the following form with x + y + z = n:
nH
C
C
Cu
H
C
Cu
C
x
+
C
H
H
2+
C
H
y
+
Cu
FeCl3
H
C
C
H
n
C
C
H
z

Polycumulene

In 1968, V.P. Nepochatykh (graduate student
Sladkov) by counter synthesis
(recovery of polymer
glycol) received a new linear
polymer of carbon with cumulene
bonds, it was called polycumulene.
Evidence of this structure was
the fact that during ozonation
polycumulene is obtained only
carbon dioxide:
C
O3
C
n
2 nCO2

Polycumulene

High molecular weight cumulene is
insoluble dark brown powder with developed
specific surface (200–300 m2/g) and density 2.25
g/cm3. When heated for many hours at 1000 °C and
reduced pressure polycumulene partially
crystallizes. In the result obtained after such annealing
product using transmission electronic
microscopy, two types of single crystals were discovered,
corresponding to the α- and β-modifications of carbyne.

Polycondensation of carbon suboxide with dimagnesium bromide

The cumulene modification of carbyne (β-carbyne) was obtained from
a specially developed two-stage method by Sladkov. On
the first stage was the polycondensation of carbon suboxide
(C3O2) with dimagnesium dibromoacetylene according to the Grignard reaction type with
formation of polymer glycol:
nO
C
C
C
O
+
n Br MgC
C MgBr
C
C
C
C
C
OH
OH
In the second stage, this polymer glycol was reduced
action of divalent tin chloride in an acidic environment:
C
C
C
OH
C
C
OH
+ n SnCl2
n
C
C
C
C
C
+ n SnO + 2n HCl
2
n
n

Dehydrohalogenation of halogenated polymers

The carbon chain is formed in advance during polymerization
corresponding monomers, and in the synthesis of carbyne the task
is that upon complete elimination of hydrogen halide
maintain this linear carbon chain. Exhaustive
dehydrohalogenation is possible if neighboring carbon atoms
there are equal numbers of halogen and hydrogen atoms. That's why
Various GSPs were convenient for obtaining carbine.
polyvinylidene halides (bromides, chlorides and fluorides), poly(1,2dibromoethylene), poly(1,1,2- and 1,2,3-trichlorobutadienes), for example:
CH2
CHal2
+B
n
-nHHal
CH
C Hal
+B
n-nHHal
C
C
n
The dehydrohalogenation reaction is usually carried out in the presence of
solutions of alkalis (B–) in ethanol with the addition of polar
solvents. When using tetrahydrofuran, synthesis occurs
at room temperature, which avoids leakage
adverse reactions.

Carbyne structure

C
C
C
C
C
C
C
C
C
C
C
C
By now
found that the structure
carbine form atoms
carbon collected in chains
double bonds (β-carbyne)
or alternating
single and triple
bonds (α-carbyne).
Polymer chains have
reactive ends and
bends with chain
vacancies in places where
chains are connected between
itself due to overlap
p-orbitals of carbon atoms
C
C
C
C
C
C
C
C
C
C
C
C

Carbyne properties:

n-type semiconductor;
electrical conductivity under the influence of light
carbine increases greatly;
carbyne does not lose photoconductivity even
at temperatures up to 500 °C;
allotropic in terms of heat capacity
forms of carbon are arranged in a row:
diamond< графит < карбин, что согласуется с
the rigidity of the oscillating frame of these
systems;
average calorific value of carbine
significantly less compared to graphite and
diamond

Carbyne in nature

A new allotropic form of carbon was discovered in
nature. In 1942, when analyzing rocks from the Arizona crater,
a crystalline white powder was discovered, which consisted
only from carbon.
Arizona Crater

Carbyne in nature

In 1967, the Soviet geochemist G.P. Vdovykin reported
discovery of a similar crystalline form in
meteorite New Uraeus.
Meteorite New Uraeus

Application of carbyne

Carbyne has already found application in electronics,
astronautics, aviation and medicine. Promisingly
Applications in optics, microwave and electrical
technologies, in the design of current sources, etc. In all
in these areas, high
stability of the material.
Taking into account the high biological compatibility and
non-toxicity of carbyne is especially important
its use in medical technology is gaining momentum.

Carbine in medicine

Sladkov and a group of employees developed fiber technology
"Vitlan" with carbine coating, from which they were created
blood vessel prostheses, durable, elastic, non-toxic,
with high thromboresistive properties.
Carbine-like carbon has found application in the manufacture of
non-breaking strong suture threads, for covering rubbing
surfaces of artificial joints, and more recently it began
also used in ophthalmology. Its use in
urology and dentistry.

“Carbyne” is a material created from carbon atoms that are assembled into a chain in a certain way. Created in the laboratory new form carbon - “Carbin”, which could be touched with your hands, was not recognized by scientists for a long time. It has not yet been discovered in nature.

Carbyne - a nanomaterial of the future

Scientists first discovered Carbin in pieces of some meteorites before it was recognized as an existing material.

After lengthy experiments, Carbin was synthesized in the laboratory, but it was such a tiny amount that the main properties had to be determined mathematically.

They calculated that the strength of “Carbin” is almost 2 times higher than the strength of “Graphene” and found that the molecules of “Carbin” do not stretch, but do not lose flexibility. This is a chemically inactive material. By adding molecules of certain substances to Carbin, you can obtain materials with completely different properties.

IN given time physical and chemical properties"Carbina" has already been well studied. The creation of materials using “Carbin” in industrial quantities begins, the strength of which is twice as strong as “Graphene”. These materials have good adhesion and are chemically inactive.

“Carbin”, like “Graphene”, has a thickness of 1 atom. This means that the surface area relative to the mass is very large. This means that it can be used in the manufacture batteries and supercapacitors.

In addition, Carbin has a number of other properties that allow it to be used in electronics and medicine.

Based on electronic properties, scientists build sensors for gas, light and the presence of life. Samsung's Advanced Technology Institute is working to develop flexible displays, transistors and storage devices.

"Carbin" has high biological compatibility, so it is widely used in medicine. Using Karbin, vascular prostheses, suture threads, and coatings for rubbing joints were created. It is already used in ophthalmology, urology and dentistry.

»
Scientific discoveries in the study of the properties of carbon.

Scientific discovery "A new crystalline form of carbon - carbyne."

Opening formula:"The previously unknown phenomenon of the existence of a new crystalline form of carbon - carbyne, characterized, unlike diamond and graphite, by a chain (linear) structure of carbon macromolecules has been experimentally established."
Authors: V. I. Kasatochkin, A. M. Sladkov, Yu. P. Kudryavtsev, V. V. Korshak.
Priority number and date: No. 107 of November 4, 1960

Description of the discovery.
Carbon – unique element. It forms countless compounds, serves as an excellent fuel and raw material for obtaining the most different materials and products made from them. Due to its structure, it forms a huge number of compounds only with hydrogen, and total quantity of all kinds of chemical compounds containing carbon, including in the cells of living beings, exceeds two million.

It was not immediately possible to find clues to the behavior of carbon, which has certain structures of atomic chains. This was preceded by decades of scientific research. For a long time, only two crystalline forms of carbon were known - diamond and graphite, which have completely different properties. Diamond, the hardest known substance on Earth, is transparent and has the characteristic properties of an electrical insulator. Graphite is very soft, opaque, and conducts current well.

Doctor of Chemical Sciences V.I. Kasatochkin from the Institute of Fossil Fuels, together with scientists from the Institute of Organoelement Compounds, Doctor of Chemical Sciences A.M. Sladkov, Candidate of Chemical Sciences Yu.P. Kudryavtsev and Corresponding Member of the USSR Academy of Sciences V.V. Korshak, discovered the phenomenon of the existence of a new crystalline form of carbon called carbyne. It was obtained from acetylene. The third form of crystalline carbon has semiconducting properties and photoconductivity.

Carbyne has also been found in its natural form. Recently, crystalline carbon with a structure similar to carbyne was discovered in the Ries crater (Bavaria), which was formed as a result of a meteorite fall. The same carbon was found by scientists from the Institute of Geochemistry of the USSR Academy of Sciences in the New Uraeus meteorite. These facts indicate that carbyne is very stable and is formed under specific natural conditions. The study of these conditions will help the development of cosmochemistry. The sharp differences in the structure and properties of the three forms of crystalline carbon: diamond, graphite and carbyne are associated with the three possible varieties of hybrid electronic structure of carbon atoms and, therefore, with differences in the types of interatomic bonds.

According to the theory of transitional forms of carbon, the combination of unequal hybrid varieties of atoms in a single polymer structure gives rise to many amorphous forms of this substance. Carbon glass is a typical example of amorphous carbon, which combines all three types of hybrid atoms with three types of bonds - diamond, graphite and carbyne. The number of combinations of hybrid atoms in different ratios is very large. That is why new carbon materials with diverse properties are now appearing. The basis of these materials is amorphous carbon.

Attention to these amazing materials around the world is increasing every year. Large specialized scientific centers are being created. The search for new carbon materials is ongoing. Extraordinary lightness, combined with heat resistance, resistance to aggressive chemical environments, and the inability to magnetize, will undoubtedly allow these substances to take a leading position among other structural materials in progressive fields of science in the near future.

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Schemes of the structure of various modifications of carbon
a: diamond, b: graphite, c: lonsdaleite
d: fullerene - buckyball C 60, e: fullerene C 540, f: fullerene C 70
g: amorphous carbon, h: carbon nanotube

More details: Allotropy of carbon

Crystalline carbon

• diamond
• Graphene
• graphite
• Carbin
• lonsdaleite
• Nanodiamond
• Fullerenes
• Fullerite
• Carbon fiber
• Carbon nanofibers
• Carbon nanotubes

Amorphous carbon

• Activated carbon
• Charcoal
• Fossil coal: anthracite, etc.
• Coal coke, petroleum coke, etc.
• Glassy carbon
• Carbon black
• Carbon nanofoam

In practice, usually the amorphous forms listed above are chemical compounds high in carbon rather than the pure allotropic form of carbon.

Cluster forms

• Astralens
• Dicarbon
• Carbon nanocones

Structure

The electron orbitals of a carbon atom can have different geometries, based on the degree of hybridization of its electron orbitals. There are three basic geometries of the carbon atom.

• tetrahedral, formed by mixing one s- and three p-electrons (sp 3 hybridization). The carbon atom is located in the center of the tetrahedron, connected by four equivalent -bonds to carbon or other atoms at the vertices of the tetrahedron. The carbon allotropic modifications diamond and lonsdaleite correspond to this geometry of the carbon atom. Carbon exhibits such hybridization, for example, in methane and other hydrocarbons.
• trigonal, formed by mixing one s- and two p-electron orbitals (sp 2 hybridization). The carbon atom has three equivalent -bonds located in the same plane at an angle of 120° to each other. The p-orbital, which is not involved in hybridization, located perpendicular to the -bond plane, is used to form -bonds with other atoms. This carbon geometry is characteristic of graphite, phenol, etc.
• digonal, formed by mixing one s- and one p-electrons (sp-hybridization). In addition, two electron clouds are elongated along the same direction and look like asymmetrical dumbbells. The other two p electrons make -bonds. Carbon with such an atomic geometry forms a special allotropic modification - Carbyne.

In 2010, University of Nottingham researchers Stephen Liddle and colleagues obtained a compound (monomeric dilithio methandium) in which four carbon atom bonds are in the same plane. The possibility of "flat carbon" had previously been predicted for the substance by Paul von Schleyer, but it was not synthesized.

Graphite and diamond

The main and well-studied allotropic modifications of carbon are diamond and graphite. Under normal conditions, only graphite is thermodynamically stable, while diamond and other forms are metastable. At atmospheric pressure and temperatures above 1200 K, diamond begins to transform into graphite; above 2100 K, the transformation takes place in seconds. H 0 transition - 1.898 kJ/mol. At normal pressure carbon sublimates at 3,780 K. Liquid carbon exists only at a certain external pressure. Triple points: graphite-liquid-vapor T = 4130 K, r= 10.7 MPa. The direct transition of graphite to diamond occurs at 3000 K and a pressure of 11-12 GPa.

At pressures above 60 GPa, the formation of a very dense modification C III (density 15-20% higher than the density of diamond), which has metallic conductivity, is assumed. At high pressures and relatively low temperatures(approx. 1,200 K) a hexagonal modification of carbon is formed from highly oriented graphite with crystal lattice wurtzite type - lonsdaleite (a = 0.252 nm, c = 0.412 nm, space group P6 3 /mmc), density 3.51 g/cm, that is, the same as that of diamond. Lonsdaleite is also found in meteorites.

Ultradisperse diamonds (nanodiamonds)

In the 1980s In the USSR, it was found that under conditions of dynamic loading of carbon-containing materials, diamond-like structures, called ultrafine diamonds (UDD), can form. Today, the term “nanodiamonds” is increasingly used. The particle size in such materials is a few nanometers. The conditions for the formation of UDD can be realized during the detonation of explosives with a significant negative oxygen balance, for example, mixtures of TNT with hexogen. Such conditions can also be realized during impacts of celestial bodies on the surface of the Earth in the presence of carbon-containing materials (organic matter, peat, coal, etc.). Yes, in the fall zone Tunguska meteorite UDAs were found in the forest floor.

Carbin

The crystalline modification of carbon of the hexagonal system with a chain structure of molecules is called Carbyne. The chains have either a polyene structure (-CC-) or a polycumulene structure (=C=C=). Several forms of carbyne are known, differing in the number of atoms in the unit cell, cell sizes and density (2.68-3.30 g/cm). Carbyne occurs in nature in the form of the mineral chaoite (white veins and inclusions in graphite) and is obtained artificially - by oxidative dehydropolycondensation of acetylene, by the action of laser radiation on graphite, from hydrocarbons or CCl 4 in low-temperature plasma.

Carbin is a fine-crystalline black powder (density 1.9-2 g/cm) and has semiconductor properties. Received in artificial conditions made up of long chains of carbon atoms arranged parallel to each other.

Carbyne is a linear polymer of carbon. In the carbyne molecule, the carbon atoms are connected in chains alternately either by triple and single bonds (polyene structure) or permanently by double bonds (polycumulene structure). This substance was first obtained by Soviet chemists V.V. Korshak, A.M. Sladkov, V.I. Kasatochkin and Yu.P. Kudryavtsev in the early 60s. at the Institute of Organoelement Compounds of the USSR Academy of Sciences. Carbyne has semiconducting properties, and its conductivity increases greatly when exposed to light. The first is based on this property practical application- in photocells.

Fullerenes and Carbon Nanotubes

Carbon is also known in the form of cluster particles C 60, C 70, C 80, C 90, C 100 and the like (Fullerenes), and in addition graphenes, nanotubes and complex structures - astralenes.

Amorphous carbon (structure)

The structure of amorphous carbon is based on the disordered structure of single-crystalline (always contains impurities) graphite. These are coke, brown and black coals, carbon black, soot, activated carbon.

Graphene

More details: Graphene

Graphene is a two-dimensional allotropic modification of carbon, formed by a layer of carbon atoms one atom thick, connected through sp bonds into a hexagonal two-dimensional crystal lattice.

Carbyne will take away the title of the most durable material from graphene if and as soon as they learn to produce it in significant quantities. This is stated in an article by theoretical physicist Boris Yakobson and his colleagues published this week.

Not long ago, graphene made all the news, becoming the most durable material. The Nobel Prize was awarded for experiments with graphene in 2010. But scientists may have synthesized a new, strongest material known as carbyne.

The properties of carbyne became known back in the summer. This material is a chain of carbon atoms connected either by double bonds in series or by alternating triple and single bonds. This, in some ways, makes carbyne a one-dimensional material - as opposed to two-dimensional graphene or three-dimensional hollow carbon nanotubes.

The new paper says that if produced in sufficient quantities, it will be possible to take advantage of some of the unique properties of carbyne. In particular, calculations have shown that the tensile strength of the new material can be twice as high as that for graphene. In addition, it is two times harder than graphene and three times harder than diamond. In addition, carbyne has pronounced semiconducting properties and can act as a material for energy storage devices.

But few people already remember that carbyne is also called ALEXEY SLADKOV’S CARBON.

In 1960, carbine was synthesized by the Soviet chemist A.M. Sladkov 1922–1982 within the walls of the Institute of Organoelement Compounds in Moscow and named by him carbine. He did not know that, having unique properties, this artificially created substance attracted the interest of the whole world and its practical use began in various areas of human activity, for example, in medicine and electronics. ‎In 1968, American scientists, A. El Goresi and G. Donnay, examining samples meteorite crater(Germany, Bavaria), demineralized them by treating them with various acids. In the insoluble concentrate it was graphite. Scientists discovered inclusions of an unknown substance of silvery-white color - carbon. The optical properties of the substance were absolutely not similar to the properties of natural diamond or its artificially obtained crystalline modification - lonsdaleite. The discovered substance turned out to be a new allotropic form of carbon (“white carbon”), which was confirmed by studying it using X-ray diffraction. Scientists have come to the conclusion that this form of ugred was formed from graphite as a result of a meteorite falling under the influence of high temperature and pressure.

The most paradoxical thing in this story is that the existence of carbine, which in the laboratory of A.M. Sladkov could be seen, touched, and experiments were conducted with him; until his discovery in nature, it was not officially recognized. More precisely, they were cautious with its recognition, thereby once again confirming how strong conservative manifestations are in science, how difficult it is to prove the fallacy of the statements of recognized authorities. One of the first who decided to challenge the authority of his predecessors was the talented Russian scientist Alexei Mikhailovich Sladkov. The work he carried out at the Institute of Organoelement Compounds, which was distinguished, according to the employees of his laboratory I. Golding and N. Vasneva, by “astonishing subtlety and clarity of design” - the oxidative polycondensation of acetylene - led to the discovery of a new linear allotropic form of carbon.

Being the son of a famous Russian chemist repressed in the thirties, a professor at the Moscow Institute of Chemical Technology. DI. Mendeleev, scientific director of the largest Institute food products and dyes (NIOPIK), A.M. Sladkov did not find recognition at that time. He avoided public affairs in every possible way and was not in the ranks of the CPSU because of his repressed father.

The author's certificate for the method of producing carbyne by the Committee for Inventions and Discoveries under the Council of Ministers of the USSR was registered as a discovery with priority of 1960 only on December 7, 1971. Those. eleven years after the series successful experiences. It took eleven years of waiting to break the mistrust of a discovery that refutes world authorities. Having received carbyne, A.M. Sladkov came to the idea of ​​the multiplicity of carbyne forms of carbon, the existence large quantity basic carbon polymers. Subsequent research by scientists confirmed this guess. Often in the scientific literature there are publications claiming the synthesis of a new crystalline form or allotropic modification of carbon.

In support of this, in 1985, for example, there was the discovery of a large family of spherical carbon molecules called fullerenes. This discovery gave new impetus to research around the world in the field of carbon and its allotropes. The authors of the next discovery - a group of American scientists - brought Nobel Prize. Doesn’t all this mean that, being the discoverer of these new forms of carbon molecules, the Russian scientist has every reason to claim, and, moreover, receive a Nobel Prize for his outstanding discovery of CARBINE!?

On at the moment obtaining carbyne remains extremely challenging task, so scientists are not yet conducting experiments with real matter, but resorting to quantum mechanical modeling on supercomputers. "IN previous works... attention was focused on some of its individual characteristics, but we set out to characterize it from all sides at once, that is, to create a complete mechanical model of the material,” says Artyukhov.

The results of such modeling showed that carbyne has a uniquely high rigidity - its specific strength per kilogram of mass is 1 million kilonewtons per meter. This is twice the strength of nanotubes and graphene (0.45 million kilonewtons) and almost three times stronger than diamond - 0.35 million kilonewtons). “We discovered several other interesting phenomena, for example, that the torsional rigidity of carbyne can be “turned on” by attaching certain functional groups to the ends,” the agency’s interlocutor said.

In addition, Jacobson and his colleagues were able to prove that when stretching a carbyne thread, its electrical properties radically change - it “transforms” from the form of cumulene (which is a conductor) to the form of polyine (a dielectric), that is, by stretching the carbyne thread, you can turn off and turn on conductivity.

Not a space elevator, but electronics

Currently, the technologies for producing carbyne are extremely complex. The longest carbyne thread - 6 nanometers - was obtained in 2010 by scientists from Canada. Therefore, according to Artyukhov, carbyne can be used as a component of various complex nanosystems. "It could serve as a 'nanocable' or 'nanorod' (depending on the length), as well as a conductive or semiconductor 'cable,'" says the scientist.

Despite its unique mechanical strength, carbyne is unlikely to be used to create ultra-strong macroscopic cables, for example, for “space elevators.”

“The fact is that the strength of a material is always determined not by the strongest, but, on the contrary, by the weakest “link” in it. In carbon fibers, these are connections between graphite sheets; in composites with nanotubes, these are contacts between the nanotube and the matrix. And no matter how much you improve the properties of the reinforcing elements in the system, its strength will remain constant if they are poorly connected to each other,” says Artyukhov.

But carbyne can be useful in electronics - depending on the tension, its conductivity and optical absorption spectrum change dramatically. “By tension you can control what wavelength of light the material is most sensitive to. This is very useful property for optoelectronic applications, in particular in telecommunications,” the scientist noted.