2,2-Dimethylpentane

2-Dimethylpentane.png Ball-and-Stick model of 2,2-Dimethylpentane 2,2-Dimethylpentane Neoheptane 2,2-DMP 590-35-2 changed CAS 11542 11055 correct chemspider 209-680-5 M82T90QEVX DTXSID5060439 changed kegg correct EBI correct EBI 1730757 CCCC(C)(C)C 1/C7H16/c1-5-6-7(2,3)4/h5-6H2,1-4H correct chemspider CXOWYJMDMMMMJO-UHFFFAOYSA-N correct chemspider 7 16 Colorless liquid Odorless 0.67385 g cm−3 (liquid, 20 °C, 1 atm)0.6695 g cm−3 (liquid, 25 °C, 1 atm)马沛生. 有机化合物实验物性数据手册--含碳氢氧卤部分[M]. 化学工业出版社, 2006：170. 149.4 352.3 0.0 D −238.5 kJ mol−1马沛生. 有机化合物实验物性数据手册--含碳氢氧卤部分[M]. 化学工业出版社, 2006：466. −4802.94 kJ mol−1 300.3 J K−1 mol−1 221.12 J K−1 mol−1 2,2-Dimethylpentane https://pubchem.ncbi.nlm.nih.gov/compound/2_2-Dimethylpentane#section=Safety-and-Hazards pubchem.ncbi.nlm.nih.gov en 02 07 08 09 Danger 225 304 315 335 336 410 210 233 240 241 242 243 261 264 271 273 280 301+310 302+352 303+361+353 304+340 312 321 331 332+313 362 370+378 391 403+233 403+235 405 501 15戈克尔. 有机化学手册[M]. 化学工业出版社, 2006：174. Material Safety Data Sheet 2,2-Dimethylpentane, 99+% http://fscimage.fishersci.com/msds/03255.htm fscimage.fishersci.com 2020-01-22 2020-09-13 https://web.archive.org/web/20200913141335/http://fscimage.fishersci.com/msds/03255.htm dead 2,2-Dimethylpentane is one of the isomers of heptane. It is also called neoheptane as it contains the (CH3)3C grouping. It has the most extreme properties of the isomers of heptane. Preparation A method to produce high purity 2,2-dimethylpentane is to react the grignard reagent of n-propyl bromide (CH3CH2CH2MgBr) with tert-butyl chloride ((CH3)3CCl).Edgar Graham Calingaert George Marker R. E. The Preparation And Properties Of The Isomeric Heptanes. Part I. Preparation Journal of the American Chemical Society May 1929 51 5 1483–1491 10.1021/ja01380a027 1929JAChS..51.1483E n-PrMgCl can be used instead of the bromide.Soroos Harold Willis H. B. The Preparation of 2,2- and 3,3-Dimethylpentane Journal of the American Chemical Society March 1941 63 3 881 10.1021/ja01848a515 1941JAChS..63..881S 400px Properties In 1929 Graham Edgar and George Calingaert made 2,2-dimethylpentane and measured its physical characteristics for the first time. The measurements were at 20 °C, not the standard conditions used in later times.Edgar Graham Calingaert George The Preparation And Properties Of The Isomeric Heptanes. Part II. Physical Properties Journal of the American Chemical Society May 1929 51 5 1540–1550 10.1021/ja01380a035 1929JAChS..51.1540E For 2,2-dimethylpentane they measured a density of 0.6737 at 20 °C with a rate of change Δd/ΔT of 0.000855. The density and boiling are the lowest of the isomers of heptane. The dielectric constant is 1.915, the lowest of the heptane isomers. The critical temperature is 247.7 °C and critical pressure 28.4 atmospheres. The refractive index at 20° is 1.38233, the same as for 2,4-dimethylpentane, equal lowest for the heptane isomers. The adiabatic compressibility is 0.0001289 and isothermal compressibility is 0.00016279 atmospheres, highest for the heptanes. The velocity of sound is 1.080 km/s which is lowest of the heptanes. Coefficient of thermal expansion is 0.001268/°, highest of the heptanes. Surface tension is 17.80 dynes/cm. Viscosity is 0.00385. The heat of combustion is 11470 cal/g which is very similar to other heptanes. Reactions 2,2-Dimethylpentane can form a clathrate hydrate with helper gas molecules. The type of clathrate formed is called "clathrate H". 2,2-Dimethylpentane was the first compound for which the structure was determined. The clathrate has 34 molecules of water per molecule, and also has xenon and hydrogen sulfide as helper molecules. The crystals are hexagonal in form and melt at 0.6 °C. This substance is important as clathrate hydrates form problems by blocking natural gas pipelines.Udachin K. A. Ratcliffe C. I. Enright G. D. Ripmeester J. A. Structure H Hydrate: A Single Crystal Diffraction Study of 2,2-dimethylpentane·5(Xe, H2S)·34H2O Supramolecular Chemistry May 1997 8 3 173–176 10.1080/10610279708034933 2,2-Dimethylpentane does not react with bromine, iodine, nitric acid or chlorosulfonic acid because there are no tertiary carbon atoms (a carbon atom with only one hydrogen attached). Heating alkanes over an aluminium trichloride is used to reform to make different isomers. 2,2-Dimethylpentane does not participate in this process and so cannot be reformed, or created by reforming other heptanes.van Eijk van Voorthuijsen J. J. B. The isomerization equilibria of the butanes, pentanes, hexanes and heptanes Recueil des Travaux Chimiques des Pays-Bas 3 September 2010 66 5 323–334 10.1002/recl.19470660508Anderson Hazel C. Bibliography of the Fischer-Tropsch Synthesis and Related Processes: Review and compilation of the literature on the production of synthetic liquid fuels and chemicals by the hydrogenation of carbon monoxide 1954 U.S. Government Printing Office 462 https://books.google.com/books?id=bJAzAAAAIAAJ&pg=PA462 en Natural occurrence 2,2-Dimethylpentane exists in some crude oils at low levelsBruun J.H. Bruun M.M.H. Note on the probable presence of 2,2-dimethylpentane in a midcontinent petroleum Bureau of Standards Journal of Research July 1932 9 1 53 10.6028/jres.009.008 free of about 0.01%.Atarshchikov S. V. Mirimanyan A. A. Mkrtychev A. A. Moderate-Temperature Isomerizate — A High-Octane Component of Automotive Gasoline Chemistry and Technology of Fuels and Oils September 2005 41 5 362–369 10.1007/s10553-005-0081-9 2005CTFO...41..362A 96819836 References Category:Alkanes