physical features
Color and personality
At room temperature, C60 is a purple solid molecular crystal with weak fluorescence.
molecular size
The diameter of C60 molecule is about 7. 1 angstrom (1 angstrom = 10- 10 meter, that is, one billionth of a meter);
density
The density of C60 is1.68g/cm3.
solubility
C60 is insoluble in strong polar solvents such as water, but soluble in nonpolar solvents such as n-hexane, benzene, carbon disulfide and carbon tetrachloride.
electrical conductivity
C60 is not conductive under normal circumstances. Because C60 is large enough to put other atoms in it, which affects its physical properties, it is not conductive. In addition, because C60 has a large number of free electrons, its half-life may be affected if radioactive elements that can decay β are trapped in it.
superconductivity
199 1 year, Hebard et al. proposed for the first time that K-doped C60 has superconductivity, and its superconducting starting temperature is 18K, which broke the record of 12.8K for organic superconductor (Et)2Cu[N(CN)2]Cl. Soon, the superconductor Rb3C60 was prepared with an initial superconducting temperature of 29K. C60 doped superconductors have entered the ranks of high temperature superconductors. The results show that this kind of materials conduct current through holes in the lattice (similar to P-type semiconductors), and if other molecules (such as tribromomethane) are added to lengthen the lattice spacing, their superconducting phase transition temperature can be effectively increased to 1 17K. China has also made great achievements in this field. In cooperation with the Institute of Physics of Chinese Academy of Sciences, Peking University successfully synthesized K3C60 and Rb3C60 superconductors with initial temperatures of 8K and 28K, respectively. Some scientists predict that if C240 and C540 are doped, it is possible to synthesize superconductors with higher initial superconducting temperature.
attraction
Allemand et al. added excessive electron-donating organic tetrakis (dimethylamino) ethylene (TDAE) into the toluene solution of C60 to obtain black microcrystalline precipitate of C60(TDAE)C0.86, which was proved to be a soft ferromagnetic material without metal by magnetic research. The Curie temperature is 16. 1K, which is higher than other organic molecular ferromagnets reported at present. Because of the important application value of organic ferromagnet in magnetic memory materials, it is of great significance to research and develop C60 organic ferromagnet, especially to replace expensive metal magnets with cheap carbon materials.
use
1. Used to strengthen metals: The strength of metal materials can be improved by alloying, plastic deformation and heat treatment. One way of strengthening is through geometric interaction, for example, carbon in coke is dispersed in metal, carbon and metal exchange positions in lattice, which can cause plastic deformation of metal, and carbon and metal form carbide particles, which can strengthen metal. In strengthening metal materials, C60 will play a better role than carbon in coke, because the particles of C60 are smaller and more active than carbon. The particle size of carbide dispersion produced by the interaction between C60 and metal is 0.7nm, while the particle size of carbide dispersion produced by the interaction between carbon and metal is 2 microns to 5 microns, which is quite different among reinforced metals. 2. aft C60 as a new catalyst was discovered, chemist began to explore that possibility of using C60 as a catalyst. C60 has the electronic structure of olefin and can form a series of complexes with transition metals (such as platinum group metals and nickel). For example, C60 can combine with platinum and osmium to form coordination compounds, such as {[(C2H5)3P]2Pt}C60 and C60OsO4 (tetra-tert-butylpyridine), which may become efficient catalysts. Researchers at Toyohashi University of Science and Technology in Japan have synthesized a highly catalytic compound C60Pd6 of palladium and C60. Researchers from Wuhan University in China synthesized Pt(PPh3)2C60(PPh3 is triphenylphosphine), which has high catalytic activity for hydrosilylation. 3. Used for gas storage: C60 can be used as a new type of hydrogen absorption material more effective than metals and their alloys due to its unique molecular structure. There are 30 carbon-carbon double bonds in each C60 molecule, so hydrogen can be absorbed by opening the double bonds in C60 molecules. At present, the stable C60 hydrides are C60H24, C60H36 and C60H48. Under the condition of controlling temperature and pressure, the hydride of C60 can be simply made of C60 and hydrogen, which is very stable at room temperature. At 80℃ ~ 2 15℃, the hydride of C60 releases hydrogen, leaving pure C60, which can be recovered 100% and used to prepare the hydride of C60 again. Compared with the hydrogen storage materials of metals or their alloys, the advantages of using C60 for hydrogen storage are lower price, and C60 is lighter than metals and their alloys. Therefore, for the same quality material, C60 stores more hydrogen than metal or its alloy. C60 can store not only hydrogen but also oxygen. Compared with high-pressure steel cylinder, the pressure of high-pressure steel cylinder is 3.9× 106Pa, which belongs to high-pressure oxygen storage method, while the pressure of C60 oxygen storage is only 2.3× 105 Pa, which belongs to low-pressure oxygen storage method. Using C60 to store a large amount of oxygen at low pressure will have many uses for medical departments, military departments and even commercial departments. 4. Used for manufacturing optical materials: C60 molecules have good optical and nonlinear optical properties due to the three-dimensional highly non-localized electron yoke structure. Because of its optical limitations, it can be used as an optical limiter in practical applications. C60 also has the characteristics of large nonlinear optical coefficient and high stability, which makes it a new type of nonlinear optical material with important research value and is expected to be applied in optical calculation, optical storage, optical signal processing and control. Others have studied the frequency doubling response and fluorescence phenomenon of C60 compounds, and photoelectric switches and optical glasses based on the photoconductive characteristics of C60 have been successfully developed. C60- arachidic acid multilayer LB films prepared by mixing C60 and arachidic acid have light accumulation and recording effects. Light limitation is also important for eye protection, because C60 will reduce the transmission performance of optical materials when increasing the intensity of incident light. Based on the optical limitation of C60, a light-limiting product can be developed, which only allows light below the sensitization threshold (that is, below the danger threshold to eyes) to pass through, thus protecting human eyes from strong light. 5. use for manufacturing polymer material: due to that special cage structure and function of C60, C60 is introduced into the polymer system as a new functional group to obtain a new functional polymer material with excellent electrical conductivity and optical properties. In principle, C60 can attract the main chain or side chain of polymer, or be mixed with other polymers. Nagashima et al reported the first case of C60 organic polymer, C60Pdn, and studied its catalytic performance for the hydrogenation of diphenylacetylene theoretically and experimentally. Y.Wany reported that the mixture of C60/C70 infiltrated into the light-emitting polymer material polyvinyl carbazole (pvk) to obtain a new type of polymer photoconductor, and its photoconductive performance was comparable to some of the best. This photoconductive material is widely used in xerography, electrostatic imaging and light detection. C60 doped with polymethyl methacrylate (PMMA) is expected to become an optical limiting material. In addition, the optical bistable behavior of C60 doped polystyrene has also been reported. 6. Biomedical application: 1) Used to make bioactive materials: Nelson et al. reported that C60 had potential tumor toxicity to the epidermis of voles. Bayer et al. believe that there is an interaction between C60 and superoxide anion. 1993 Friedman et al. predicted theoretically that some C60 derivatives can inhibit the HIV activity of human immunodeficiency protease, and the key to AIDS research is to effectively inhibit the HIV activity. Japanese scientists reported that a water-soluble C60 carboxyl derivative had the characteristics of inhibiting the growth of toxic cells and cracking DNA under visible light irradiation, which opened up a broad prospect for the application of C60 derivatives in photodynamic therapy. Toniolo et al. reported a water-soluble C60- polypeptide derivative in 1994, which may have potential application in chemotaxis of human monocytes and inhibition of HIV- 1 protease. Huang Wendong et al. prepared water-soluble C60- liposome and found that it has a strong killing effect on cancer cells. Scientists in Taiwan Province Province, China reported that fullerene, a derivative of polyhydroxy C60, has the function of devouring superoxide anion radicals produced by xanthine oxidase, and also has excellent scavenging effect on hydroxyl radicals with strong destructive power. Using the anti-radiation characteristics of C60 molecules, injecting radioactive elements into the cancerous parts of carbon cages can improve the curative effect of radiotherapy and reduce the side effects. 2) Killing effect on cancer cells: After C60 is stimulated by light, the output of singlet oxygen is high, and singlet oxygen has an important relationship with physiological and biochemical functions, tissue damage, tumor and phototherapy technology. When the lasing intensity of C60 reaches 4000lx, cancer cells are almost 100% dead under the action of singlet oxygen, which can effectively destroy the important structures of cancer cells such as plasma membrane, mitochondrial endoplasmic reticulum and nuclear membrane, thus leading to cancer cell damage and even death. Another study pointed out that the antibody of tumor cells can be attached to C60 molecules, and then C60 molecules with antibodies can be introduced into tumors, which can also achieve the purpose of killing tumor cells. 3) Other medical effects: C60 derivatives can inhibit the activity of human immunodeficiency protease. Human immunodeficiency protease is a virus that causes AIDS. Therefore, C60 derivatives may play a role in AIDS prevention and treatment research. C60 is also suitable as a free radical scavenger and water-soluble antioxidant in biological systems. Free radicals are harmful substances, which can cause some diseases and even tumors. C60 is expected to reduce the concentration of free radicals in patients' blood and inhibit the growth of abnormal and diseased cells. Other uses: C60F60 is a derivative of C60, commonly known as polytetrafluoroethylene, which can be used as "molecular ball" and "molecular lubricant" and plays an important role in high-tech development. Embedding lithium atoms into carbon cages is expected to make high-performance lithium batteries. The human rare earth element europium embedded in carbon cage is expected to become a new rare earth luminescent material. C60 derivative of water-soluble gadolinium is expected to be a new nuclear magnetic contrast agent. C60 can be transformed into diamond under high pressure, which opens up a new source of diamond. C60 and its derivatives may become new catalysts and new nano-scale molecular wires, molecular straws and whisker reinforced composites. The water-soluble host-guest complexes formed by C60, cyclodextrin and polycyclic aromatic hydrocarbons will play an important role in supramolecular chemistry and bionic chemistry. Because C60 thin film can be used as matrix material to make dentate combined capacitor, the chemical sensor made of C60 thin film has the advantages of small size, simplicity, renewable and low price compared with traditional sensors, and may become an attractive candidate product in the sensor. Fullerenes also have memory and can be used as memory materials.