![]() ![]() Īt ambient conditions, adamantane crystallizes in a face-centered cubic structure ( space group Fm3m, a = 9.426 ± 0.008 Å, four molecules in the unit cell) containing orientationally disordered adamantane molecules. The carbon–hydrogen distances are 1.112 Å. The carbon–carbon bond lengths are 1.54 Å, almost identical to that of diamond. Structure Īs deduced by electron diffraction and X-ray crystallography, the molecule has T d symmetry. Adamantane can be distilled with water vapor. However, adamantane slowly sublimes even at room temperature. At 270 ☌, its melting point is much higher than other hydrocarbons with the same molecular weight, such as camphene (45 ☌), limonene (−74 ☌), ocimene (50 ☌), terpinene (60 ☌) or twistane (164 ☌), or than a linear C 10H 22 hydrocarbon decane (−28 ☌). Adamantane has an unusually high melting point for a hydrocarbon. It is practically insoluble in water, but readily soluble in nonpolar organic solvents. Pure adamantane is a colorless, crystalline solid with a characteristic camphor smell. Their isolation from a complex mixture of hydrocarbons is possible due to their high melting point and the ability to distill with water vapor and form stable adducts with thiourea. Petroleum contains more than thirty derivatives of adamantane. Petroleum remains a source of adamantane the content varies from between 0.0001% and 0.03% depending on the oil field and is too low for commercial production. Because of the (assumed) similarity of its structure to that of diamond, the new compound was named adamantane. could produce only a few milligrams of adamantane, but noticed its high boiling and melting points. They used fractional distillation of petroleum based. Natural occurrence Īdamantane was first isolated from petroleum by the Czech chemists S. Slow cooling of the tube, while maintaining the temperature gradient, gradually shifts the melting zone (rate ~2 mm/hour) producing a single-crystal boule. Crystallization starts at one end of the tube, which is kept near the freezing point of adamantane. Adamantane is sublimed in a quartz tube placed in a furnace, which is equipped with several heaters maintaining a certain temperature gradient (about 10 ☌/cm for adamantane) along the tube. Growth from the vapor phase is a reasonable compromise in terms of speed and quality. The best crystals are obtained from the liquid phase, but the growth is impracticably slow – several months for a 5–10 mm crystal. Melt growth results in the worst crystalline quality with a mosaic spread in the X-ray reflection of about 1°. with the Bridgman–Stockbarger technique). Using this powder, single crystals can be grown from the melt, solution, or vapor phase (e.g. Īll the above methods yield adamantane as a polycrystalline powder. Other researchers attempted to synthesize adamantane using phloroglucinol and derivatives of cyclohexanone, but also failed. The product, tricyclo-, was not adamantane, but a derivative. Bottger tried to obtain adamantane using Meerwein's ester as precursor. Instead of adamantane, Meerwein obtained 1,3,5,7-tetracarbomethoxybicyclononane-2,6-dione: this compound, later named Meerwein's ester, was used in the synthesis of adamantane and its derivatives. The first attempted laboratory synthesis was made in 1924 by German chemist Hans Meerwein using the reaction of formaldehyde with diethyl malonate in the presence of piperidine. Decker suggested the existence of adamantane, which he called decaterpene. Adamantane derivatives have found practical application as drugs, polymeric materials, and thermally stable lubricants. The discovery of adamantane in petroleum in 1933 launched a new field of chemistry dedicated to the synthesis and properties of polyhedral organic compounds. It is a white solid with a camphor-like odor. This similarity led to the name adamantane, which is derived from the Greek adamantinos (relating to steel or diamond). The spatial arrangement of carbon atoms in the adamantane molecule is the same as in the diamond crystal. Adamantane is the most stable isomer of C 10H 16. ![]() The molecule is both rigid and virtually stress-free. Adamantane molecules can be described as the fusion of three cyclohexane rings. Adamantane is an organic compound with a formula C 10H 16 or, more descriptively, (CH) 4(CH 2) 6. ![]()
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