n -hexatriacontane

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Structural formula
Structure of n-hexatriacontane
General
Surname n -hexatriacontane
other names

Hexatriacontane

Molecular formula C 36 H 74
Brief description

white odorless crystals

External identifiers / databases
CAS number 630-06-8
EC number 211-127-8
ECHA InfoCard 100.010.117
PubChem 12412
Wikidata Q151185
properties
Molar mass 506.97 g mol −1
Physical state

firmly

density
  • 0.96 g cm −3 (20 ° C)
  • 0.78 g cm −3 (melt at 76 ° C)
Melting point

76 ° C

boiling point

497 ° C

solubility

almost insoluble in water

Refractive index

1.4397 (80 ° C)

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

n -Hexatriacontan is a long-chain, unbranched and saturated alkane . It belongs to the group of higher alkanes .

Presentation and extraction

It is produced by the Wurtz synthesis from octadecyl iodide and sodium .

properties

Hexatriacontane occurs in three polymorphic crystal forms. Form I melts at 76 ° C with a melting enthalpy of 88.74 kJ mol −1 . Two solid phase transitions precede the melting point. At 72 ° C the conversion of form III to form II takes place, at 74 ° C the conversion from form II to form I. At room temperature, crystal form III is the thermodynamically stable form. The compound can occur in monoclinic crystal lattices for forms II and III and an orthorhombic crystal lattice for form I.

The vapor pressure curve can be calculated in the temperature range from 452 K to 516 K using the August equation as log 10 ( p ) = A - ( B / T ) ( p in kPa, T in K) with A = 14.67 and B = 8228 describe. The enthalpy of vaporization is 157 kJ mol −1 .

The compound can be mixed indefinitely with n-heptane . The solubility curve shows only a low content of hexatriacontane at low temperatures, which increases very quickly with increasing temperature.

DSC measurement on n-hexatriacontane Solubility curve in n-heptane

use

Hexatriacontane is used as the standard in solid-state NMR spectroscopy .

Individual evidence

  1. ↑ a b c Lan Wang, Zhi-Cheng Tan, Shuang-He Meng, Dong-Bai Liang: Low-temperature heat capacity and phase transition of n-hexatriacontane. In: Thermochim. Acta . 342, 1999, pp. 59-65. doi: 10.1016 / S0040-6031 (99) 00308-1
  2. ↑ a b c d e data sheet n-hexatriacontane at AlfaAesar, accessed on February 24, 2012 ( PDF )(JavaScript required) .
  3. ^ A b c V. Vand: Density and Unit Cell of n-Hexatriacontane. In: Acta Cryst. 6, 1953, pp. 797-798. doi: 10.1107 / S0365110X53002246
  4. ↑ a b c J. C. Company: Measurement and interpretation of crystallization equilibriums of heavy paraffin and aromatic hydrocarbon solutions. In: Chem. Eng. Sci. 28, 1973, pp. 318-323. doi: 10.1016 / 0009-2509 (73) 85117-6
  5. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-282.
  6. ^ RK Doolittle, RH Peterson: Preparation and Physical Properties of a Series of n-Alkanes. In: J. Am. Chem. Soc. 73, 1951, pp. 2145-2149. doi: 10.1021 / ja01149a069
  7. ↑ a b A. A. Schaerer, CJ Busso, AE Smith, LB Skinner: Properties of pure normal alkanes in the C17 to C36 range. In: J. Am. Chem. Soc. 77, 1955, pp. 2017-2019. doi: 10.1021 / ja01612a097
  8. ↑ a b K. L. Roberts, RW Rousseau, AS Teja: Solubility of Long-Chain n-Alkanes in Heptanes between 280 and 350 K. In: J. Chem. Eng. Data . 39, 1994, pp. 793-795. doi: 10.1021 / je00016a035
  9. ↑ HMM Shearer, V. Vand: The crystal structure of the monoclinic form of n-hexatriacontane. In: Acta Cryst. 9, 1956, pp. 379-384. doi: 10.1107 / S0365110X5600111X
  10. ↑ PW Teare: The crystal structure of orthorhombic hexatriacontane, C 36 H 74 . In: Acta Cryst. 12, 1959, pp. 294-300. doi: 10.1107 / S0365110X59000901
  11. ↑ Hidehiko Honda, Hiroshi Ogura, Shuichi Tasaki, Akio Chiba: Two-phase coexisting state of n-hexatriacontane in the first-order phase transition. In: Thermochim. Acta. 405, 2003, pp. 51-60. doi: 10.1016 / S0040-6031 (03) 00135-7
  12. ↑ Hideki Kubota, Fumitoshi Kaneko, Tatsuya Kawaguchi, Masatsugu Kawasaki: Infrared spectroscopic study on polytypic transformation of growing single crystal of n-hexatriacontane nC 36 H 74 . In: J. Cryst. Growth. 275, 2005, pp. E1751 – e1756. doi: 10.1016 / j.jcrysgro.2004.11.163
  13. ↑ a b V. Piacente, D. Fontana, P. Scardala: Enthalpies of Vaporization of a Homologous Series of n-Alkanes Determined from Vapor Pressure Measurements. In: J. Chem. Eng. Data . 39, 1994, pp. 231-237. doi: 10.1021 / je00014a009
  14. Jump up ↑ Hideki Kubota, Fumitoshi Kaneko, Chikayo Akita, Tatsuya Kawaguchi: The Influence of Polytropic Structures on the Solid-state 13 C NMR Spectra of n-Alkanes. In: Chem. Lett. 33, 2004, pp. 1358-1359. doi: 10.1246 / cl.2004.1358