287-92-3 Usage
Physical and chemical properties
Cyclopentane, also known as "pentamethylene", is a kind of cycloalkane with the formula of C5H10. It has a molecular weight of 70.13. It exists as a kind of flammable liquid. It has a melting point-94.4 °C, boiling point of 49.3 °C, relative density of 0.7460 and the refractive index of 1.4068. It is soluble in alcohol, ether and hydrocarbons and is not soluble in water. Cyclopentane is not a planar ring and has two conformations: envelope conformations and semi-chair conformations. The carbon-carbon-carbon bond angle is close to 109 ° 28 ' with the molecular tension not big and the ring being relatively stable. It has a similar chemical property as alkanes. The lethal concentration in the air for the rats was 3.8 × 10-2. It exhibits red yellow color when having reaction with fuming sulfuric acid while generating nitro cyclopentane and glutaric acid through reaction with nitric acid. Method: it can be obtained from the petroleum ether distillate, through high-pressure cracking on the cyclohexane in the presence of aluminum or catalytic hydrogenation of cyclopentene and cyclopentadiene. Purposes: mainly used as a solvent.
Figure 1 the cyclopentane structure.
Cycloalkane
Cycloalkanes are saturated hydrocarbons in which the carbon atoms in the molecule are arranged in a ring and a sufficient number of hydrogen atoms are combined. Cycloalkanes presented in petroleum are mainly cyclopentane and cyclohexane.
Cycloalkanes have a higher melting point, boiling point, and relative density than the corresponding straight-chain alkanes. We can use the naphthenic aromatic crude oil to produce high-octane straight-run gasoline with its anti-explosion being better than normal paraffin. Low sulfur-containing paraffin naphthenic crude oil, is not only easy to process, but also an excellent raw material for the production of advanced lubricants. Petroleum containing relative many polycyclic long side chain naphthenic compounds is an ideal material for high-quality lubricants.
At room temperature and atmospheric pressure, cycloalkane containing four or less carbon atoms is in the gas form with those contain more than four carbons existing in the liquid form. The cyclopropane and cyclobutane appear as gas, cyclopentane to cycloundecane appears as liquid; cyclododecane and above appears as solid.
The chemical nature of the cycloalkane is related to the number of carbon atoms forming the ring. It is referred three-membered ring and four-membered ring, as small ring; the five-to-seven-membered ring as normal ring; the eight-eleven ring as normal ring; the twelve-membered ring and above as large ring. The nuclei lines of carbon nuclei in small rings are not consistent with the axis of bonding orbital. In cyclopropane, the ring formed by the nucleus lines of carbon atoms is an equilateral triangle with each angle being 60° while the angle of the sp3 hybrid orbital axis of carbon-carbon single bonds formed by each carbon 104° (see figure 2 below). Therefore, the orbit has failed to achieve the greatest degree of overlap, causing a large angle tension. Cyclobutane also has angular tension, but being smaller. This leads to the poor stability of the small ring, causing its similar chemical property to olefins that can have ring-opening addition reaction with many reagents. Other ring has less of no angular tension. Cycloalkane and alkanes have similar chemical properties, less prone to have ring-opening reaction such as having reaction with hydrogen. Cyclohexane and higher cycloalkane is more difficult to undergo hydrogenation.
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Figure 2 is a schematic representation of sp3 hybridization orbital overlap in cyclopropane.
Cyclopropane (at room temperature) and cyclobutane (at the heating conditions) can have addition reaction with halogen and hydrogen halide.
The open-loop occurs between the two atoms connecting the most and least numbers of hydrogen. The addition satisfies the Markovian rule. While the normal ring, under the stimulation of the light or heat can have substitution reaction with the halogen.
At room temperature, cycloalkane can’t be oxidized by potassium permanganate.
Cyclopentane, cyclohexane and its alkyl substituted products are presented in certain petroleum oils. Cycloalkanes may also be synthesized by suitable methods, such as dihaloalkane cyclization and hydrogenation of aromatic hydrocarbons.
This information was edited by Xiaonan from lookchem (2015-08-17).
Dangerous situation
Ingestion and inhalation are moderately toxic. (2) Being flammable with greater risk of combustion. The allowable concentration in air is 600ppm (1720mg/m3) in the United States.
Harmful effects and symptoms of poisoning
Inhalation of high concentrations of cyclopentane can cause central nervous system inhibition, although its acute toxicity is low. Symptoms of acute exposure include excitement at first, followed by the emergence of balance disorders, and even stupor, coma. There are rarely cases of death due to respiratory failure. It has been reported that animals fed with this goods can get severe diarrhea, leading to heart, lung and liver vascular collapse and brain degeneration.
Protective measures
It can be used for improving the production equipment. Use skin protective creams or gloves to protect the skin.
Medical care
Upon regular physical examination, pay attention to the potential irritation effect of skin and respiratory tract as well as any complications of kidney and liver.
Transportation requirements
Grade I flammable liquid. Code of Hazard Regulations: 61013. The container shall be marked with a "flammable liquid" mark on transport.
Fire extinguishing agent
See “cyclohexane”.
Recommended waste disposal methods
Incineration;
Chemical properties
It appears as colorless liquid with a melting point of-93.9 °C, the boiling point of 49.26 ° C, the relative density of 0.7460 (20/4 ° C), the refractive index of 1.4068 and the flash point of-37 °C. It is miscible with alcohol, ether and other organic solvents, being not be easy to be dissolved in water.
Uses
Different sources of media describe the Uses of 287-92-3 differently. You can refer to the following data:
1. (1)??? It can be used as a solvent for solution polymerization of polyisoprene rubber and cellulose ether. It can be used as a substitute for Freon as insulation materials in refrigerators and freezers as well as foaming agents for other hard PU foams, and chromatographic analysis standards.
(2)??? Used as a standard substance for chromatographic analysis, solvents, engine fuels, azeotropic distillation agents.
2. Cyclopentane is a petroleum product. Itis formed from high-temperature catalyticcracking of cyclohexane or by reduction ofcyclopentadiene. It occurs in petroleum etherfractions and in many commercial solvents.It is used as a solvent for paint, in extractionsof wax and fat, and in the shoe industry.
3. As a laboratory reagent; in the manufacture
of pharmaceuticals; found in solvents
and in petroleum ether; propellant pressurizing
agent.
4. Cyclopentane is used as green blowing agent and involved in the production of polyurethane insulating foam, which is used in refrigerators, freezers, water heaters, construction panels, insulated pipes and roofs. As a lubricant, it finds applications in computer hard drives and outer space equipment due to its low volatile nature. It is widely useful in the preparation of resin, adhesives and pharmaceutical intermediate. It is an additive in gasoline. Since it is a halogen free compound and has zero-ozone depletion potential, it replaces the conventionally used chloro fluoro carbon (CFC) in refrigeration and thermal insulation.
Production method
Cyclopentane is a component of the petroleum ether in the 30-60 °C boiling point range with the content being generally 5%-10%. Apply atmospheric distillation; at a 60: 1 reflux ratio and carry out at an 8m height tower; first distill out the isopentane and n-pentane; continue fractionation to obtain a cyclopentane with purity being over 98%. Cyclopentane can also be obtained through cyclopentanone reduction or cyclopentadiene catalytic hydrogenation.
Hazards & Safety Information
Category Flammable liquids
Toxicity grading: Low toxicity
Acute toxicity: oral-rat LD50: 11400 mg/kg; oral-mouse LD50: 12800 mg/kg
Hazardous property of explosives: being explosive upon mixed with air
Flammability and dangerous situations: being flammable in case of fire, high temperature and oxidant with combustion releasing irritant smoke
Storage characteristics: Storehouse: ventilated, low temperature and dry; Store it with oxidant separately
Extinguishing agent: Dry powder, carbon dioxide, foam, 1211 extinguishing agent
Occupational standard: TWA 1720 mg/m3; STEL 2150 mg/kg
Chemical Properties
Cyclopentane is a colourless flammable acyclic hydrocarbon liquid with a petrol-like smell. It is a widely used component in preparing products like analgesics, insecticides, sedatives, antitumor agents and also finds application in pharmaceutical industry.
Physical properties
Colorless, mobile, flammable liquid with an odor resembling cyclohexane.
Production Methods
Cyclopentane occurs in petroleum ether fractions and is
prepared by cracking cyclohexane in the presence of alumina
at high temperature and pressure or by reduction of cyclopentadiene.
Definition
ChEBI: A cycloalkane that consists of five carbons each bonded with two hydrogens above and below the plane. The parent of the class of cyclopentanes.
General Description
A clear colorless liquid with a petroleum-like odor. Flash point of -35°F. Less dense than water and insoluble in water. Vapors are heavier than air.
Air & Water Reactions
Highly flammable. Insoluble in water.
Reactivity Profile
CYCLOPENTANE is incompatible with strong oxidizing agents such as chlorine, bromine, fluorine. .
Health Hazard
Cyclopentane is a low-acute toxicant. Itsexposure at high concentrations may producedepression of the central nervous system withsymptoms of excitability, loss of equilibrium,stupor, and coma. Respiratory failure may occur in rats from 30–60 minutes’ exposureto 100,000–120,000 ppm in air. It is anirritant to the upper respiratory tract, skin,and eyes. No information is available inthe literature on the chronic effects fromprolonged exposure to cyclopentane.
Fire Hazard
Behavior in Fire: Containers may explode.
Flammability and Explosibility
Highlyflammable
Chemical Reactivity
Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
Safety Profile
Mildly toxic by
ingestion and inhalation. High
concentrations have narcotic action. A very
dangerous fire hazard when exposed to heat
or flame; can react with oxidizers. To fight
fire, use foam, CO2, dry chemical. When
heated to decomposition it emits acrid
smoke and fumes.
Potential Exposure
Cyclopentane is used as a solvent.
Source
Component of high octane gasoline (quoted, Verschueren, 1983). Harley et al. (2000)
analyzed the headspace vapors of three grades of unleaded gasoline where ethanol was added to replace methyl tert-butyl ether. Cyclopentane was detected at an identical concentration of 1.4 wt
% in the headspace vapors for regular, mid-, and premium grades.
Schauer et al. (1999) reported cyclopentane in a diesel-powered medium-duty truck exhaust at
an emission rate of 410 μg/km.
California Phase II reformulated gasoline contained cyclopentane at a concentration of 4.11
g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without
catalytic converters were 0.78 and 85.4 mg/km, respectively (Schauer et al., 2002).
Environmental fate
Biological. Cyclopentane may be oxidized by microbes to cyclopentanol, which may oxidize to
cyclopentanone (Dugan, 1972).
Photolytic. The following rate constants were reported for the reaction of octane and OH
radicals in the atmosphere: 3.7 x 10-12 cm3/molecule?sec at 300 K (Hendry and Kenley, 1979); 5.40
x 10-12 cm3/molecule?sec (Atkinson, 1979); 4.83 x 10-12 cm3/molecule?sec at 298 K (DeMore and
Bayes, 1999); 6.20 x 10-12, 5.24 x 10-12, and 4.43 x 10-12 cm3/molecule?sec at 298, 299, and 300 K,
respectively (Atkinson, 1985), 5.16 x 10-12 cm3/molecule?sec at 298 K (Atkinson, 1990), and 5.02
x 10-12 cm3/mol·sec at 295 K (Droege and Tilly, 1987).
Chemical/Physical. Cyclopentane will not hydrolyze because it has no hydrolyzable functional
group. Complete combustion in air yields carbon dioxide and water.
At elevated temperatures, rupture of the ring occurs forming ethylene and presumably allene
and hydrogen (Rice and Murphy, 1942).
Shipping
UN1146 Cyclopentane, Hazard Class: 3; Labels:
3-Flammable liquid.
Purification Methods
Free it from cyclopentene by two passages through a column of carefully dried and degassed activated silica gel. It occurs in petroleum and is HIGHLY FLAMMABLE. [NMR: Christl Chem Ber 108 2781 1975, Whitesides et al. 41 2882 1976, Beilstein 5 III 10, 5 IV 4.]
Incompatibilities
May form explosive mixture with air.
May accumulate static electrical charges, and may cause
ignition of its vapors. Contact with strong oxidizers may
cause fire and explosion.
Waste Disposal
Dissolve or mix the material
with a combustible solvent and burn in a chemical incinera-
tor equipped with an afterburner and scrubber. All federal,
state, and local environmental regulations must be
observed.
Check Digit Verification of cas no
The CAS Registry Mumber 287-92-3 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 2,8 and 7 respectively; the second part has 2 digits, 9 and 2 respectively.
Calculate Digit Verification of CAS Registry Number 287-92:
(5*2)+(4*8)+(3*7)+(2*9)+(1*2)=83
83 % 10 = 3
So 287-92-3 is a valid CAS Registry Number.
InChI:InChI=1/C5H10/c1-2-4-5-3-1/h1-5H2
287-92-3Relevant articles and documents
CATALYTIC HYDROGENATION RATE OF CYCLOPENTENE IN PRESENCE OF PALLADIUM CLUSTER n
Berenblyum, A. S.,Mund, S. L.,Danilova, L. G.,Moiseev, I. I.
, p. 686 - 689 (1981)
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Dissociation Dynamics of Energy-Selected C5H10(1+) Ions
Brand, Willi A.,Baer, Tomas
, p. 3154 - 3160 (1984)
The fragmentation reactions of six C5H10(1+) isomers loosing CH3 and C2H4 have been investigated by using the photoelectron photoion coincidence (PEPICO) technique.Except for the 2-methyl-2-butene ion dissociation all precursors exhibit a two-component decay indicating that dissociation occurs from at least two distinct forms of molecular ions.The observation is rationalized in terms of competition between dissociation from the original ion structure and isomerization to a lower energy isomer subsequently decomposing at a slower rate.The latter isomer is identified as the 2-methyl-2-butene molecular ion.The comparison of the measured absolute rates with those predicted by the statistical theory (RRKM/QET) suggests that the transition-state switching model is necessary for a quantitative agreement.
Heterogeneous catalysis. VII. Gas phase hydrogenolysis of polyhalogenated compounds. Possible decontamination of poisonous wastes
Roth,Von Rague Schleyer
, p. 1697 - 1699 (1983)
-
Fabricating nickel phyllosilicate-like nanosheets to prepare a defect-rich catalyst for the one-pot conversion of lignin into hydrocarbons under mild conditions
Cao, Meifang,Chen, Bo,He, Chengzhi,Ouyang, Xinping,Qian, Yong,Qiu, Xueqing
supporting information, p. 846 - 857 (2022/02/09)
The one-pot conversion of lignin biomass into high-grade hydrocarbon biofuels via catalytic hydrodeoxygenation (HDO) holds significant promise for renewable energy. A great challenge for this route involves developing efficient non-noble metal catalysts to obtain a high yield of hydrocarbons under relatively mild conditions. Herein, a high-performance catalyst has been prepared via the in situ reduction of Ni phyllosilicate-like nanosheets (Ni-PS) synthesized by a reduction-oxidation strategy at room temperature. The Ni-PS precursors are partly converted into Ni0 nanoparticles by in situ reduction and the rest remain as supports. The Si-containing supports are found to have strong interactions with the nickel species, hindering the aggregation of Ni0 particles and minimizing the Ni0 particle size. The catalyst contains abundant surface defects, weak Lewis acid sites and highly dispersed Ni0 particles. The catalyst exhibits excellent catalytic activity towards the depolymerization and HDO of the lignin model compound, 2-phenylethyl phenyl ether (PPE), and the enzymatic hydrolysis of lignin under mild conditions, with 98.3% cycloalkane yield for the HDO of PPE under 3 MPa H2 pressure at 160 °C and 40.4% hydrocarbon yield for that of lignin under 3 MPa H2 pressure at 240 °C, and its catalytic activity can compete with reported noble metal catalysts.
Ambient Hydrogenation and Deuteration of Alkenes Using a Nanostructured Ni-Core–Shell Catalyst
Beller, Matthias,Feng, Lu,Gao, Jie,Jackstell, Ralf,Jagadeesh, Rajenahally V.,Liu, Yuefeng,Ma, Rui
supporting information, p. 18591 - 18598 (2021/06/28)
A general protocol for the selective hydrogenation and deuteration of a variety of alkenes is presented. Key to success for these reactions is the use of a specific nickel-graphitic shell-based core–shell-structured catalyst, which is conveniently prepared by impregnation and subsequent calcination of nickel nitrate on carbon at 450 °C under argon. Applying this nanostructured catalyst, both terminal and internal alkenes, which are of industrial and commercial importance, were selectively hydrogenated and deuterated at ambient conditions (room temperature, using 1 bar hydrogen or 1 bar deuterium), giving access to the corresponding alkanes and deuterium-labeled alkanes in good to excellent yields. The synthetic utility and practicability of this Ni-based hydrogenation protocol is demonstrated by gram-scale reactions as well as efficient catalyst recycling experiments.
Improved Hydrodeoxygenation of Phenol to Cyclohexane on NiFe Alloy Catalysts Derived from Phyllosilicates
Han, Qiao,Wang, Hui,Rehman, Mooeez Ur,Shang, Xin,Chen, Haijun,Ji, Na,Tong, Xinli,Shi, Hui,Zhao, Yujun
supporting information, p. 5069 - 5076 (2021/12/14)
A phyllosilicate-derived NiFe/SiO2 catalyst (NiFe/SiO2?AE) was successfully prepared by the ammonia evaporation method and applied in the hydrodeoxygenation of phenol to cyclohexane. Another two catalysts were also prepared for a comparison by impregnation (NiFe/SiO2?IM) and deposition-precipitation (NiFe/SiO2?DP) methods, respectively. It was found that Ni?Fe alloy, the active sites for the hydrogenolysis of C?O bond, can be obtained by the reduction of NiFe2O4 (IM) or phyllosilicate (DP and AE) by H2. The AE strategy can generate more phyllosilicate structure, which improves the dispersion of both Ni?Fe alloy and metallic Ni sites and allows the formation of more interface between these two kinds of sites as well. Therefore, the NiFe/SiO2?AE exhibits a significantly high catalytic performance in the HDO of phenol to cyclohexane. Moreover, the turnover frequency of Ni?Fe alloy sites over NiFe/SiO2?AE catalysts is much higher than those of other two catalysts. It is suggested that the enhanced synergy between the two kinds of active sites in the adsorption of C?O groups and hydrogen molecules ensures the superior intrinsic activity in HDO process.
