cycloheptane

{{chembox

| Watchedfields = changed

| verifiedrevid = 414090033

| Name = Cycloheptane

| ImageFileL1 = cycloheptane.svg

| ImageClassL1 = skin-invert-image

| ImageAltL1 = Skeletal formula

| ImageFileR1 = Cycloheptane-3D-balls.png

| ImageClassR1 = bg-transparent

| ImageAltR1 = Ball-and-stick model

| PIN = Cycloheptane

|Section1={{Chembox Identifiers

| SMILES = C1CCCCCC1

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 8908

| PubChem = 9265

| InChI = 1/C7H14/c1-2-4-6-7-5-3-1/h1-7H2

| InChIKey = DMEGYFMYUHOHGS-UHFFFAOYAF

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 453194

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C7H14/c1-2-4-6-7-5-3-1/h1-7H2

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = DMEGYFMYUHOHGS-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 291-64-5

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = VTZ53P34JA

| EINECS = 206-030-2

| UNNumber = 2241

}}

|Section2={{Chembox Properties

| C=7 | H=14

| Appearance = colorless oily liquid

| Density = 0.8110 g/cm³

| MeltingPtC = -12

| BoilingPtC = 118.4

| Viscosity =

| Solubility = negligible

| SolubleOther = very soluble in ethanol, ether
soluble in benzene, chloroform

| LogP = 4.0

| RefractIndex = 1.4436

}}

|Section7={{Chembox Hazards

| GHSPictograms = {{GHS02}}{{GHS08}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|225|304|412}}

| PPhrases = {{P-phrases|210|233|240|241|242|243|273|280|301+310|303+361+353|331|370+378|403+235|405|501}}

| FlashPtC = 6

| NFPA-H = 1

| NFPA-F = 3

| NFPA-R = 0

}}

|Section8={{Chembox Related

| OtherFunction_label = cycloalkanes

| OtherFunction = Cyclohexane Cyclooctane

}}

Cycloheptane, also known as Suberane,{{cite web | title=DNB, Katalog der Deutschen Nationalbibliothek | publisher=Deutsche Nationalbibliothek | date=2024-12-06 | url=https://portal.dnb.de/opac.htm?method=simpleSearch&cqlMode=true&query=nid%3D4351760-2 | language=de | access-date=2025-02-06}} is an organic compound, which belongs to the group of cycloalkanes. The compound can occur in different conformers.

Production

Cycloheptane occurs naturally in petroleum and can be extracted from it. It is synthesized by a Clemmensen reduction from cycloheptanone.{{cite web | last=Communications | first=EBCONT | title=Cycloheptan | website=RÖMPP, Thieme | url=https://roempp.thieme.de/lexicon/RD-03-03116 | language=de | access-date=2025-02-05}}

Properties

Cycloheptane is a colorless liquid with a mild, aromatic odor. The boiling point at normal pressure is 119°C. The molar enthalpy of vaporization is 38.5 kJ mol⁻¹. According to the Antoine equation, the vapor pressure function is given by log₁₀(P) = A−(B/(T+C)) (P in bar, T in K) with A = 3,97710, B = 1330,402 and C = −56,946 in the temperature range from 341.3 K to 432.2 K.

In the solid phase, cycloheptane occurs in four polymorphic forms.{{cite journal | last1=Domalski | first1=Eugene S. | last2=Hearing | first2=Elizabeth D. | title=Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III | journal=Journal of Physical and Chemical Reference Data | volume=25 | issue=1 | date=1996-01-01 | issn=0047-2689 | doi=10.1063/1.555985 | doi-access=free | page=1 | bibcode=1996JPCRD..25....1D | url=https://pubs.aip.org/aip/jpr/article-pdf/25/1/1/17367533/1_1_1.555985.pdf | access-date=2025-02-05}} The transformation temperatures for the conversion from form IV to form III are −138°C, from form III to form II −75°C and from form II to form I −61°C. Form I melts at −8°C.{{cite web | title=Cycloheptan | website=gestis.dguv.de | url=https://gestis.dguv.de/data?name=037750 | access-date=2025-02-05}}

class="wikitable"

|+Compilation of the most important thermodynamic properties

! width="30%" |Property

! width="10%" |Type

! width="30%" |Value [Unit]

! width="30%" |Note

Standard enthalpy of formation

|Δ_fH⁰_liquid

|−156,4 kJ·mol⁻¹{{cite journal | last1=Spitzer | first1=Ralph | last2=Huffman | first2=Hugh M. | title=The Heats of Combustion of Cyclopentane, Cyclohexane, Cycloheptane and Cyclooctane | journal=Journal of the American Chemical Society | volume=69 | issue=2 | date=1947 | issn=0002-7863 | doi=10.1021/ja01194a006 | pages=211–213| pmid=20292425 | bibcode=1947JAChS..69..211S }}

Standard entropy

|S⁰_liquid

|242,55 J·mol⁻¹·K⁻¹{{cite journal | last1=Finke | first1=H. L. | last2=Scott | first2=D. W. | last3=Gross | first3=M. E. | last4=Messerly | first4=J. F. | last5=Waddington | first5=Guy | title=Cycloheptane, Cycloöctane and 1,3,5-Cycloheptatriene. Low Temperature Thermal Properties, Vapor Pressure and Derived Chemical Thermodynamic Properties | journal=Journal of the American Chemical Society | volume=78 | issue=21 | date=1956 | issn=0002-7863 | doi=10.1021/ja01602a003 | pages=5469–5476| bibcode=1956JAChS..78.5469F }}

|as a liquid

Heat of combustion

|Δ_cH⁰_liquid

|−4598,9 kJ·mol⁻¹

Heat capacity

|c_p

|180,614 J·mol⁻¹·K⁻¹ (25 °C){{cite journal | last1=Fortier | first1=Jean-Luc | last2=D'arcy | first2=Patrick J. | last3=Benson | first3=George C. | title=Heat capacities of binary cycloalkane mixtures at 298.15 K | journal=Thermochimica Acta | publisher=Elsevier BV | volume=28 | issue=1 | year=1979 | issn=0040-6031 | doi=10.1016/0040-6031(79)87005-7 | pages=37–43| bibcode=1979TcAc...28...37F }}

132,0 J·mol⁻¹·K⁻¹ (25 °C){{Cite journal |last1=Dorofeeva |first1=O. V. |last2=Gurvich |first2=L. V. |last3=Jorish |first3=V. S. |date=1986-04-01 |title=Thermodynamic Properties of Twenty-One Monocyclic Hydrocarbons |url=https://pubs.aip.org/jpr/article/15/2/437/241328/Thermodynamic-Properties-of-Twenty-One-Monocyclic |journal=Journal of Physical and Chemical Reference Data |language=en |volume=15 |issue=2 |pages=437–464 |doi=10.1063/1.555773 |bibcode=1986JPCRD..15..437D |issn=0047-2689}}

|as a liquid

as a gas

Triple point

|T_triple

|265,12 K

Critical temperature

|T_c

|604,2 K{{cite journal | last=Daubert | first=Thomas E. | title=Vapor−Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes | journal=Journal of Chemical & Engineering Data | volume=41 | issue=3 | date=1996-01-01 | issn=0021-9568 | doi=10.1021/je9501548 | pages=365–372}}

Critical pressure

|p_c

|38,2 bar

Critical volume

|V_c

|0.353 l·mol⁻¹

Critical density

|ρ_c

|2,83 mol·l⁻¹

= Chemical properties =

Cycloheptane can be thermally rearranged to methylcyclohexane in the presence of aluminum trichloride.

File:Cycloheptane rearrangement to methylcyclohexane.svg

Functionalization can be achieved by chlorination with N-chlorosuccinimide.{{cite journal | last1=Buu-Hoï | first1=Ng. Ph. | last2=Demerseman | first2=P. | title=Halogenation of Saturated Compounds with N-Chloro-And N-Bromo-Succinimide | journal=The Journal of Organic Chemistry | volume=18 | issue=6 | date=1953 | issn=0022-3263 | doi=10.1021/jo01134a005 | pages=649–652}}

File:Cycloheptane NCS chlorination.svg

The compound is flammable and forms flammable vapour-air mixtures with air. The flash point is 6 °C, the lower explosion limit is 1.1 vol.%.

Usage

Cycloheptane can be used as a non-polar solvent. In organic synthesis, the cycloheptyl functional groups can be introduced into organic molecules, e.g. pharmaceutical active ingredients, after functionalization.

Hazards

An irritating effect on the eyes and respiratory tract is mentioned in the literature. The toxic effect is more comparable to that of methylcyclohexane, which only slightly irritates the mucous membranes. Animal experiments showed only a slight irritating effect on the skin. Systemically, cycloheptane has a depressant effect on the central nervous system.

References

Category:Cycloalkanes

Category:Hydrocarbon solvents

Category:Seven-membered rings