Syntin

Syntin

Names
Preferred IUPAC name 21-Methyl-11,21:22,31-tercyclopropane
Other names 1-Methyl-1,2-dicyclopropylcyclopropane; Sintin; Synthin; Tsycklin
Identifiers
CAS Number	93223-46-2 Y
3D model (JSmol)	Interactive image
ChemSpider	452765 Y
PubChem CID	519050
CompTox Dashboard (EPA)	DTXSID90333879
InChI InChI=1S/C10H16/c1-10(8-4-5-8)6-9(10)7-2-3-7/h7-9H,2-6H2,1H3 N Key: GTKAAVZEFUFXDD-UHFFFAOYSA-N N InChI=1/C10H16/c1-10(8-4-5-8)6-9(10)7-2-3-7/h7-9H,2-6H2,1H3 Key: GTKAAVZEFUFXDD-UHFFFAOYAR
SMILES CC1(C2CC2)C(C3CC3)C1
Properties
Chemical formula	C10H16
Molar mass	136.238 g·mol−1
Density	0.851 g/mL
Boiling point	158 °C (316 °F; 431 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Syntin is a hydrocarbon with the molecular formula C₁₀H₁₆ used as a rocket fuel. It is a mixture of four stereoisomers (see below). It has a density of 0.851 g/mL, and a boiling point of 158 °C. Due to the presence of three strained cyclopropane rings, the molecule has a highly positive enthalpy of formation: Δ_fH°(l)= 133 kJ/mol (980 kJ/kg, the average value for the isomeric mixture), bringing additional energy into the combustion process. It has advantages over the traditional hydrocarbon fuels, such as RP-1, due to higher density, lower viscosity and higher specific heat of oxidation.

Syntin was used in the Soviet Union and later Russia in 1980–1990s as fuel for the Soyuz-U2 rocket. It was first synthesized in the USSR in the 1960s and brought to mass production in the 1970s. It was prepared in a multi-step synthetic process from easily obtained acetylcyclopropane (the 3rd molecule):

After dissolution of the USSR, the production of this fuel was halted due to the expense of the synthesis.

Stereoisomers[]

Syntin is a molecule with two stereocenters at the central cyclopropane ring. Thus, the following four stereoisomers may exist:

In practice, the fuel has been used as mixture of all four stereoisomers.

See also[]

• dicyclopentadiene

References[]

This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please help to improve this article by introducing more precise citations. (January 2013) (Learn how and when to remove this template message)

• A. P. Mesheheryakov, V. G. Glukhovtsev, A. D. Petrov, “Synthesis of 1-methyl-1,2-dicyclopropylcyclopropane”, Doklady Akademii Nauk SSSR, 1960, 130, 779-81.
• Yu. P. Semenov, B. A. Sokolov, S. P. Chernykh, A. A. Grigor'ev, O. M. Nefedov, N. N. Istomin, G. M. Shirshov, “Multiple strained-ring alkane as high-performance liquid rocket fuel”, RU 2233385, C2 20040727.
• T. Edwards, “Liquid Fuels and Propellants for Aerospace Propulsion: 1903-2003”, Journal of Propulsion and Power, 2003, 19(6), 1089-1107.
• V. Azov, D. Vorontsov, "The last battle of hydrocarbons?", Novosti Kosmonavtiki, 2008, 18, No. 2 (301), 44-46.