Adamantane
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| General | ||||||||||||||||||||||
| Surname | Adamantane | |||||||||||||||||||||
| other names |
Tricyclo [3.3.1.1 3.7 ] decane |
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| Molecular formula | C 10 H 16 | |||||||||||||||||||||
| Brief description |
colorless solid with a camphor smell |
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| properties | ||||||||||||||||||||||
| Molar mass | 136.23 g mol −1 | |||||||||||||||||||||
| Physical state |
firmly |
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| density |
1.07 g cm −3 (20 ° C) |
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| Melting point |
266-268 ° C |
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| solubility |
almost insoluble in water |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||||||||||||||
Adamantane is a bridged hydrocarbon and the simplest diamondoid . It forms colorless crystals that smell like camphor . Formally, the structure of adamantane consists of four cyclohexane molecules in a chair conformation . This highly symmetrical structure ( point group T d ) is also found in other chemical substances such as methenamine and phosphorus trioxide ; it is sometimes referred to as adamantane-like .
Occurrence
Adamantane occurs naturally only in traces in some rock crystals . It is also found in small amounts in the petroleum from which it was first isolated ( Stanislav Landa , 1933).
synthesis
The tricyclic hydrocarbon is easily accessible by rearrangement of tetrahydrodicyclopentadiene , which is produced by hydrogenation of the Diels-Alder dimer of cyclopentadiene , using aluminum chloride . The production takes place at 160 ° C and approx. 3 MPa.
With an improved synthesis with superacid as a catalyst via the detour of a synthesis of 1,3-dialkyl-adamantane, the adamantane can be incorporated into polymers using a Sun Oil process .
Over 10,000 tons of adamantane are produced annually.
properties
Physical Properties
Adamantane is a solid substance at room temperature that occurs in two polymorphic crystal forms. At room temperature, the crystal form I is present, which changes into the liquid phase at 270 ° C. A phase transition from crystal form II to form I is observed at −64.5 ° C. Here the transition from the crystalline to a plastic crystalline form takes place. This means that the compound is in a mesomorphic state above this temperature up to the melting point and thus also at room temperature . The behavior is analogous to similar "spherical" molecules such as cubane or tetramethylbutane , which form similar mesophases.
Chemical properties
Adamantane is very stable and generally not very reactive. Eliminations are impossible, Bredt's rule applies to all carbon atoms. Substitution reactions mainly take place at the bridgehead C1. Adamantane is almost insoluble in water.
use
Adamantane is used in polymer compounds to improve resistance to solvents , chemicals and heat . It is used as a matrix for radicals and as a reference substance in solid-state NMR spectroscopy . Due to the high symmetry of the molecules, there is a molecular rotation in the solid that is particularly easy to measure.
It is also used to manufacture other adamantane derivatives :
- Adamantan-1-ylamine ( amantadine ) is used against Parkinson's disease and against the flu caused by the influenza A virus . It has a preventive effect against the influenza A virus H5N1 of the bird flu H5N1 48 hours after infection.
- 3,5-Dimethyl-adamantan-1-ylamine ( memantine ) is used as an anti- dementia agent in the treatment of moderate to severe dementia of the Alzheimer's type.
Individual evidence
- ↑ Entry on Adamantane. In: Römpp Online . Georg Thieme Verlag, accessed April 30, 2014.
- ↑ a b c d e data sheet adamantane at AlfaAesar, accessed on May 23, 2017 ( PDF )(JavaScript required) .
- ↑ S. Landa, V. Macháček: Sur l'adamantane, nouvel hydrocarbure extrait du naphte . In: Coll. Czech. Chem. Comm. tape 5 , 1933, pp. 1-5 , doi : 10.1135 / cccc19330001 .
- ↑ H. Stetter: The chemistry of organic ring systems with urotropine structure . In: Angewandte Chemie . tape 66 , no. 8 , 1954, pp. 217-229 , doi : 10.1002 / anie.19540660802 .
- ^ Paul von R. Schleyer , MM Donaldson, RD Nicholas, C. Cupas: Adamantane In: Organic Syntheses . 42, 1962, p. 8, doi : 10.15227 / orgsyn.042.0008 ; Coll. Vol. 5, 1973, pp. 16-19 ( PDF ).
- ↑ JTS Andrews, RE Carpenter, TM Martinko, RC Fort, TA Flood, MG Adlington: Transition and Fusion Thermodynamics of Heteroadamantanes. In: Mol. Cryst. Liq. Cryst. 41, 1978, pp. 257-261, doi: 10.1080 / 00268947808070312 .
- ↑ P. Espeau, R. Ceolin: Thermodynamic studies of solids with non-negligible vapor pressure: T – v and p – T diagrams of the dimorphism of adamantane. In: Thermochimica Acta . 73, 2001, pp. 147-154, doi: 10.1016 / S0040-6031 (01) 00561-5 .
- ↑ GJ Kabo, AV Blokhin, MB Charapennikau, AG Kabo, VM Sevruk: Thermodynamic properties of adamantan and the energy states of molecules in plastic crystals for some cage hydrocarbons. In: Thermochimica Acta . 345, 2000, pp. 125-133, doi: 10.1016 / S0040-6031 (99) 00393-7 .
- ↑ FH Herbstein: Some applications of thermodynamics in crystal chemistry. In: J. Mol. Structure . 374, 1996, pp. 111-128, doi: 10.1016 / 0022-2860 (95) 08996-9 .
- ^ TH Maugh: Panel urges wide use of antiviral drug . In: Science . tape 206 , no. 4422 , November 30, 1979, ISSN 0036-8075 , p. 1058-1060 , doi : 10.1126 / science.386515 , PMID 386515 .
- ↑ Claire Mount, Christian Downton: Alzheimer's disease: progress or profit? In: Nature Medicine . tape 12 , no. 7 , July 1, 2006, p. 780-784 , doi : 10.1038 / nm0706-780 .
