Butane

Butane (/ˈbjuːteɪn/) is an organic compound with the formula C4H10 that is an alkane with four carbon atoms. Butane is a gas at room temperature and atmospheric pressure. The term may refer to either of two structural isomers, n-butane or isobutane (also called "methylpropane"), or to a mixture of these isomers. In the IUPAC nomenclature, however, "butane" refers only to the n-butane isomer (which is the isomer with the unbranched structure). Butanes are highly flammable, colorless, easily liquefied gases that quickly vaporize at room temperature. The name butane comes from the roots but- (from butyric acid, named after the Greek word for butter) and -ane. It was discovered by the chemist Edward Frankland in 1849.[6] It was found dissolved in crude petroleum in 1864 by Edmund Ronalds, who was the first to describe its properties.[7][8]

Butane
Skeletal formula of butane with all implicit hydrogens shown
Skeletal formula of butane with all carbon and hydrogen atoms shown
Ball-and-stick model of the butane molecule
Space-filling model of the butane molecule
Names
Preferred IUPAC name
Butane[3]
Systematic IUPAC name
Tetracarbane (never recommended[3])
Other names
Butyl hydride[1]
Quartane[2]
Identifiers
3D model (JSmol)
969129
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.136
EC Number 203-448-7
E number E943a (glazing agents, ...)
1148
KEGG
MeSH butane
RTECS number EJ4200000
UNII
UN number 1011
Properties
C4H10
Molar mass 58.124 g·mol−1
Appearance Colorless gas
Odor Gasoline-like or natural gas-like[1]
Density 2.48 kg/m3 (at 15 °C (59 °F))
Melting point −140 to −134 °C; −220 to −209 °F; 133 to 139 K
Boiling point −1 to 1 °C; 30 to 34 °F; 272 to 274 K
61 mg L−1 (at 20 °C (68 °F))
log P 2.745
Vapor pressure ~170 kPa at 283 K [4]
11 nmol Pa−1 kg−1
Conjugate acid Butanium
-57.4·10−6 cm3/mol
Thermochemistry
98.49 J K−1 mol−1
−126.3–−124.9 kJ mol−1
−2.8781–−2.8769 MJ mol−1
Hazards[5]
Safety data sheet See: data page
GHS pictograms GHS02: Flammable
GHS signal word DANGER
H220
P210
NFPA 704
Flash point −60 °C (−76 °F; 213 K)
405 °C (761 °F; 678 K)
Explosive limits 1.8–8.4%
US health exposure limits (NIOSH):
PEL (Permissible)
none[1]
REL (Recommended)
TWA 800 ppm (1900 mg/m3)[1]
IDLH (Immediate danger)
N.D.[1]
Related compounds
Related alkanes
Related compounds
Perfluorobutane
Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Thermodynamic
data
Phase behaviour
solid–liquid–gas
UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Isomers

Common name normal butane
unbranched butane
n-butane
isobutane
i-butane
IUPAC name butane 2-methylpropane
Molecular
diagram
Butan Lewis Isobutane 1
Skeletal
diagram
Butane simple I-Butane-2D-Skeletal

Rotation about the central C−C bond produces two different conformations (trans and gauche) for n-butane.[9]

Reactions

Spectrum of blue flame - intensity corrected
Spectrum of the blue flame from a butane torch showing CH molecular radical band emission and C2 Swan bands

When oxygen is plentiful, butane burns to form carbon dioxide and water vapor; when oxygen is limited, carbon (soot) or carbon monoxide may also be formed.

When there is sufficient oxygen:

2 C4H10 + 13 O2 → 8 CO2 + 10 H2O

When oxygen is limited:

2 C4H10 + 9 O2 → 8 CO + 10 H2O

The maximum adiabatic flame temperature of butane with air is 2,243 K (1,970 °C; 3,578 °F).

n-Butane is the feedstock for DuPont's catalytic process for the preparation of maleic anhydride:

2 CH3CH2CH2CH3 + 7 O2 → 2 C2H2(CO)2O + 8 H2O

n-Butane, like all hydrocarbons, undergoes free radical chlorination providing both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorination is partially explained by the differing bond dissociation energies, 425 and 411 kJ/mol for the two types of C-H bonds.

Uses

Normal butane can be used for gasoline blending, as a fuel gas, fragrance extraction solvent, either alone or in a mixture with propane, and as a feedstock for the manufacture of ethylene and butadiene, a key ingredient of synthetic rubber. Isobutane is primarily used by refineries to enhance (increase) the octane number of motor gasoline.[10][11][12][13]

When blended with propane and other hydrocarbons, it may be referred to commercially as LPG, for liquefied petroleum gas. It is used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays such as deodorants.[14]

Very pure forms of butane, especially isobutane, can be used as refrigerants and have largely replaced the ozone-layer-depleting halomethanes, for instance in household refrigerators and freezers. The system operating pressure for butane is lower than for the halomethanes, such as R-12, so R-12 systems such as in automotive air conditioning systems, when converted to pure butane will not function optimally and therefore a mix of isobutane and propane is used to give cooling system performance comparable to R-12.

Butane is also used as lighter fuel for a common lighter or butane torch and is sold bottled as a fuel for cooking, barbecues and camping stoves. Butane canisters global market is dominated by South Korean manufacturers.[15]

As fuel, it is often mixed with small amounts of hydrogen sulfide and mercaptans which will give the unburned gas an offensive smell easily detected by the human nose. In this way, butane leaks can easily be identified. While hydrogen sulfide and mercaptans are toxic, they are present in levels so low that suffocation and fire hazard by the butane becomes a concern far before toxicity. Most commercially available butane also contains a certain amount of contaminant oil which can be removed through filtration but which will otherwise leave a deposit at the point of ignition and may eventually block the uniform flow of gas. Contaminants are not used in fragrance extraction and butane gases can cause gas explosions in poorly ventilated areas if leaks go unnoticed and are ignited by spark or flame.

Photo D2 The Green Lighter 1 ies Aerosol ButaneGasCylinder WhiteBack
Butane fuel canisters for use in camping stoves. Butane lighter, showing liquid butane reservoir An aerosol spray can, which may be using butane as a propellant Butane gas cylinder used for cooking

Effects and health issues

Inhalation of butane can cause euphoria, drowsiness, unconsciousness, asphyxia, cardiac arrhythmia, fluctuations in blood pressure and temporary memory loss, when abused directly from a highly pressurized container, and can result in death from asphyxiation and ventricular fibrillation. It enters the blood supply and within seconds produces intoxication.[16] Butane is the most commonly misused volatile substance in the UK, and was the cause of 52% of solvent related deaths in 2000.[17] By spraying butane directly into the throat, the jet of fluid can cool rapidly to −20 °C (−4 °F) by expansion, causing prolonged laryngospasm.[18] "Sudden sniffer's death" syndrome, first described by Bass in 1970,[19] is the most common single cause of solvent related death, resulting in 55% of known fatal cases.[18]

A small amount of nitrogen dioxide, a toxic gas, results from burning butane gas, along with any combustion in the earth's atmosphere, and represents a human health hazard from home heaters and stoves.[20]

See also

References

  1. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0068". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ Hofmann, August Wilhelm Von (1 January 1867). "I. On the action of trichloride of phosphorus on the salts of the aromatic monamines". Proceedings of the Royal Society of London. 15: 54–62. doi:10.1098/rspl.1866.0018. Retrieved 20 September 2018 – via rspl.royalsocietypublishing.org.
  3. ^ a b "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 4. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4. Similarly, the retained names ‘ethane’, ‘propane’, and ‘butane’ were never replaced by systematic names ‘dicarbane’, ‘tricarbane’, and ‘tetracarbane’ as recommended for analogues of silane, ‘disilane’; phosphane, ‘triphosphane’; and sulfane, ‘tetrasulfane’.
  4. ^ W. B. Kay (1940). "Pressure-Volume-Temperature Relations for n-Butane". Industrial & Engineering Chemistry. 32 (3): 358–360. doi:10.1021/ie50363a016.
  5. ^ "Safety Data Sheet, Material Name: N-Butane" (PDF). USA: Matheson Tri-Gas Incorporated. 5 February 2011. Archived from the original (PDF) on 1 October 2011. Retrieved 11 December 2011.
  6. ^ "Occ paper" (PDF). www.chem.qmul.ac.uk.
  7. ^ Watts, H. (1868). Dictionary of Chemistry. 4. p. 385.
  8. ^ Maybery, C.F. (1896). "On the Composition of the Ohio and Canadian Sulphur Petroleums". Proceedings of the American Academy of Arts and Sciences. 31: 1–66.
  9. ^ Roman M. Balabin (2009). "Enthalpy Difference between Conformations of Normal Alkanes: Raman Spectroscopy Study of n-Pentane and n-Butane". J. Phys. Chem. A. 113 (6): 1012–9. doi:10.1021/jp809639s. PMID 19152252.
  10. ^ MarkWest Energy Partners, L.P. Form 10-K. Sec.gov
  11. ^ Copano Energy, L.L.C. Form 10-K. Sec.gov. Retrieved on 2012-12-03.
  12. ^ Targa Resources Partners LP Form10-k. Sec.gov. Retrieved on 2012-12-03.
  13. ^ Crosstex Energy, L.P. FORM 10-K. Sec.gov
  14. ^ A Primer on Gasoline Blending. An EPRINC Briefing Memorandum
  15. ^ "Entrepreneur overcame hardships of Chinese prison". houstonchronicle.com. 21 June 2016. Retrieved 20 September 2018.
  16. ^ "Neurotoxic Effects from Butane Gas". thcfarmer.com. 19 Dec 2009. Retrieved 3 October 2016.
  17. ^ Field-Smith M, Bland JM, Taylor JC, et al. "Trends in death Associated with Abuse of Volatile Substances 1971–2004" (PDF). Department of Public Health Sciences. London: St George’s Medical School. Archived from the original (PDF) on March 27, 2007.
  18. ^ a b Ramsey J, Anderson HR, Bloor K, et al. (1989). "An introduction to the practice, prevalence and chemical toxicology of volatile substance abuse". Hum Toxicol. 8 (4): 261–269. doi:10.1177/096032718900800403. PMID 2777265.
  19. ^ Bass M. (1970). "Sudden sniffing death". JAMA. 212 (12): 2075–2079. doi:10.1001/jama.1970.03170250031004. PMID 5467774.
  20. ^ Ghosn, Marwan; Flouty, Roula; Saliba, Najat A. (2005). "Emission of Nitrogen Dioxide from Butane Gas Heaters and Stoves Indoors". American Journal of Applied Sciences. 2 (3): 707. doi:10.3844/ajassp.2005.707.710.

External links

1,4-Butanediol

1,4-Butanediol, colloquially known as BD, is the organic compound with the formula HOCH2CH2CH2CH2OH. It is a colorless viscous liquid. It is one of four stable isomers of butanediol.

Adipic acid

Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annually, mainly as a precursor for the production of nylon. Adipic acid otherwise rarely occurs in nature, but it is known as manufactured E number food additive E355.

Blowtorch

A blowtorch (U.S. and Australia), or blowlamp (UK), is a fuel-burning tool used for applying flame and heat to various applications, usually metalworking.

Early blowtorches used liquid fuel, carried in a refillable reservoir attached to the lamp. Modern blowtorches are mostly gas-fuelled. Their fuel reservoir is disposable or refillable by exchange. The term "blowlamp" usually refers to liquid-fuelled torches still used in the UK. Liquid-fuelled torches are pressurized by a piston hand pump, while gas torches are self-pressurized by the fuel evaporation.

Fuel torches are available in a vast range of size and output power. The term blowtorch applies to the smaller and lower temperature range of these. Blowtorches are typically a single hand-held unit, with their draught supplied by a natural draught of air. The larger torches may have a heavy fuel reservoir placed on the ground, connected by a hose. This is common for butane- or propane-fuelled gas torches, but also applies to the older, large liquid paraffin (kerosene) torches such as the Wells light.

Many torches now use a hose-supplied gas feed, which is often mains gas. They may also have a forced-air supply, from either an air blower or an oxygen cylinder. Both of these larger and more powerful designs are less commonly described as blowtorches, while the term blowtorch is usually reserved for the smaller and less powerful self-contained torches. The archaic term "blowpipe" is sometimes still used in relation to oxy-acetylene welding torches.

(British English uses the word "blowtorch" to mean a cutting torch as used for cutting metal, often any oxy-fuel welding and cutting torch.)

Bottle

A bottle is a narrow-necked container made of an impermeable material (clay, glass, plastic, aluminium, clay, etc.) in various shapes and sizes to store and transport liquids (water, milk, beer, wine, ink, cooking oil, medicine, soft drinks, shampoo, and chemicals, etc.) and whose mouth at the bottling line can be sealed with an internal stopper, an external bottle cap, a closure, or a conductive "inner seal" using induction sealing.

Some of the earliest bottles appeared in China, Phoenicia, Crete, and Rome.

Butadiene

1,3-Butadiene is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a monomer in the production of synthetic rubber. The molecule can be viewed as the union of two vinyl groups. It is the simplest conjugated diene.

Although butadiene breaks down quickly in the atmosphere, it is nevertheless found in ambient air in urban and suburban areas as a consequence of its constant emission from motor vehicles.The name butadiene can also refer to the isomer, 1,2-butadiene, which is a cumulated diene with structure H2C=C=CH−CH3. This allene has no industrial significance.

Butyl group

In organic chemistry, butyl is a four-carbon alkyl radical or substituent group with general chemical formula −C4H9, derived from either of the two isomers of butane.

The isomer n-butane can connect in two ways, giving rise to two "-butyl" groups:

If it connects at one of the two terminal carbon atoms, it is normal butyl or n-butyl: CH3−CH2−CH2−CH2− (fully systematic name: butyl)

If it connects at one of the non-terminal (internal) carbon atoms, it is secondary butyl or sec-butyl: CH3−CH2−CH(CH3)− (fully systematic name: 1-methylpropyl)The second isomer of butane, isobutane, can also connect in two ways, giving rise to two additional groups:

If it connects at one of the three terminal carbons, it is isobutyl: (CH3)2CH−CH2− (fully systematic name: 2-methylpropyl)

If it connects at the central carbon, it is tertiary butyl, tert-butyl or t-butyl: (CH3)3C− (fully systematic name: 1,1-dimethylethyl)

Diacetyl

Diacetyl (IUPAC systematic name: butanedione or butane-2,3-dione) is an organic compound with the chemical formula (CH3CO)2. It is a yellow or green liquid with an intensely buttery flavor. It is a vicinal diketone (two C=O groups, side-by-side) with the molecular formula C4H6O2. Diacetyl occurs naturally in alcoholic beverages and is added to some foods to impart its buttery flavor.

Erythritol

Erythritol is a sugar alcohol (or polyol) food additive. It was discovered in 1848 by Scottish chemist John Stenhouse. Erythritol was first isolated in 1852. In 1950 it was found in blackstrap molasses that was fermented by yeast, and it became commercialized as a sugar alcohol in the 1990s in Japan.It occurs naturally in some fruit and fermented foods. At the industrial level, it is produced from glucose by fermentation with a yeast, Moniliella pollinis. Erythritol is 60–70% as sweet as sucrose (table sugar) yet it is almost noncaloric, does not affect blood sugar, does not cause tooth decay, and is partially absorbed by the body, excreted in urine and feces. Under U.S. Food and Drug Administration (FDA) labeling requirements, it has a caloric value of 0.2 kilocalories per gram (95% less than sugar and other carbohydrates), though nutritional labeling varies from country to country. Some countries, such as Japan and the United States, label it as zero-calorie; the European Union labels it 0 kcal/g.

Gas cylinder

A gas cylinder or tank is a pressure vessel for storage and containment of gases at above atmospheric pressure. High-pressure gas cylinders are also called bottles. Inside the cylinder the stored contents may be in a state of compressed gas, vapor over liquid, supercritical fluid, or dissolved in a substrate material, depending on the physical characteristics of the contents. A typical gas cylinder design is elongated, standing upright on a flattened bottom end, with the valve and fitting at the top for connecting to the receiving apparatus.

Hash oil

Hash oil, also known as honey oil or cannabis oil, is an oleoresin obtained by the extraction of cannabis or hashish. It is a concentrated form of cannabis extracts containing many of its resins and terpenes – in particular, tetrahydrocannabinol (THC), cannabidiol (CBD), and other cannabinoids. There are various extraction methods, most involving a solvent, such as butane or ethanol. Hash oil is usually consumed by smoking, vaporizing or eating. Hash oil may be sold in cartridges used with pen vaporizers. Preparations of hash oil may be solid or colloidal depending on both production method and temperature and are usually identified by their appearance or characteristics. Color most commonly ranges from transparent golden or light brown, to tan or black. Cannabis retailers in California have reported about 40% of their sales are from cannabis oils.Hash oil is an extracted cannabis product that may use any part of the plant, with minimal or no residual solvent. It is generally thought to be indistinct from traditional hashish, according to the 1961 UN Single Convention on Narcotic Drugs (Schedule I and IV), as it is "the separated resin, whether crude or purified, obtained from the cannabis plant".

Ingūna Butāne

Ingūna Butāne (born February 24, 1986), sometimes simply known as Inguna, is a Latvian model.

Butāne was discovered when a contest was held in Latvia, where she met agents from Women Management in Milan, Italy, but decided to finish her degree of Interior Design. She then went to Moscow, Russia, and subsequently to New York, USA, to start her career.She has been in ad campaigns for Armani Jeans, Bergdorf Goodman, Dolce & Gabbana, L'Oréal, Marc (a second line of Marc Jacobs), and Neiman Marcus. Her runway work includes Fendi, Alexander McQueen, Viktor and Rolf, Yohji Yamamoto, Alice Roi, Baby Phat, Belstaff, Gucci, Versace, and Oscar de la Renta. She is currently signed with Mother New York.

In 2005 Butāne worked with Steven Meisel as part of the 80-page "Makeover Madness" feature in Italian Vogue, which also included Linda Evangelista and Jessica Stam. In 2007 she worked with Annie Liebovitz on an ad campaign for Bottega Veneta, along with Anja Rubik, Kim Noorda, and Noah Mills.She walked in the Victoria's Secret Fashion Show in 2005, 2007 and 2008.

Butāne is the daughter of a professional violinist. She played the violin when she was young. She loves to listen to classical music.

Isobutane

Isobutane, also known as i-butane, 2-methylpropane or methylpropane, is a chemical compound with molecular formula HC(CH3)3. It is an isomer of butane. It is the simplest alkane with a tertiary carbon. Isobutane is used as a precursor molecule in the petrochemical industry, for example in the synthesis of isooctane.

Isopentane

Isopentane, C5H12, also called methylbutane or 2-methylbutane, is a branched-chain alkane with five carbon atoms. Isopentane is an extremely volatile and extremely flammable liquid at room temperature and pressure. It is also the least dense liquid at standard conditions for temperature and pressure.The normal boiling point is just a few degrees above room temperature and isopentane will readily boil and evaporate away on a warm day. Isopentane is commonly used in conjunction with liquid nitrogen to achieve a liquid bath temperature of −160 °C. Natural gas typically contains 1% or less isopentane.

Lighter

A lighter is a portable device used to create a flame, and to ignite a variety of combustible materials, such as cigars, gas stoves, fireworks, candles or cigarettes. It consists of a metal or plastic container filled with a flammable fluid or pressurized liquid gas, a means of ignition to produce the flame, and some provision for extinguishing the flame. Alternatively, a lighter can be powered by electricity, using an electric arc or heating element to ignite the target.

Liquefied petroleum gas

Liquefied petroleum gas or liquid petroleum gas (LPG or LP gas), also referred to as simply propane or butane, are flammable mixtures of hydrocarbon gases used as fuel in heating appliances, cooking equipment, and vehicles.

It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as autogas.

Varieties of LPG bought and sold include mixes that are mostly propane (C3H8), mostly butane (C4H10), and, most commonly, mixes including both propane and butane. In the northern hemisphere winter, the mixes contain more propane, while in summer, they contain more butane. In the United States, mainly two grades of LPG are sold: commercial propane and HD-5. These specifications are published by the Gas Processors Association (GPA) and the American Society of Testing and Materials (ASTM). Propane/butane blends are also listed in these specifications.

Propylene, butylenes and various other hydrocarbons are usually also present in small concentrations. HD-5 limits the amount of propylene that can be placed in LPG to 5%, and is utilized as an autogas specification. A powerful odorant, ethanethiol, is added so that leaks can be detected easily. The internationally recognized European Standard is EN 589. In the United States, tetrahydrothiophene (thiophane) or amyl mercaptan are also approved odorants, although neither is currently being utilized.

LPG is prepared by refining petroleum or "wet" natural gas, and is almost entirely derived from fossil fuel sources, being manufactured during the refining of petroleum (crude oil), or extracted from petroleum or natural gas streams as they emerge from the ground. It was first produced in 1910 by Dr. Walter Snelling, and the first commercial products appeared in 1912. It currently provides about 3% of all energy consumed, and burns relatively cleanly with no soot and very few sulfur emissions. As it is a gas, it does not pose ground or water pollution hazards, but it can cause air pollution. LPG has a typical specific calorific value of 46.1 MJ/kg compared with 42.5 MJ/kg for fuel oil and 43.5 MJ/kg for premium grade petrol (gasoline). However, its energy density per volume unit of 26 MJ/L is lower than either that of petrol or fuel oil, as its relative density is lower (about 0.5–0.58 kg/L, compared to 0.71–0.77 kg/L for gasoline).

As its boiling point is below room temperature, LPG will evaporate quickly at normal temperatures and pressures and is usually supplied in pressurised steel vessels. They are typically filled to 80–85% of their capacity to allow for thermal expansion of the contained liquid. The ratio between the volumes of the vaporized gas and the liquefied gas varies depending on composition, pressure, and temperature, but is typically around 250:1. The pressure at which LPG becomes liquid, called its vapour pressure, likewise varies depending on composition and temperature; for example, it is approximately 220 kilopascals (32 psi) for pure butane at 20 °C (68 °F), and approximately 2,200 kilopascals (320 psi) for pure propane at 55 °C (131 °F). LPG is heavier than air, unlike natural gas, and thus will flow along floors and tend to settle in low spots, such as basements. There are two main dangers from this. The first is a possible explosion if the mixture of LPG and air is within the explosive limits and there is an ignition source. The second is suffocation due to LPG displacing air, causing a decrease in oxygen concentration.

A "full" LPG cylinder contains 85% liquid, the ullage volume will contain vapour at a pressure that varies with temperature.

Open-chain compound

In chemistry, an open-chain compound (also spelled as open chain compound) or acyclic compound (Greek prefix "α", without and "κύκλος", cycle) is a compound with a linear structure, rather than a cyclic one.

An open-chain compound having no side chains is called a straight-chain compound (also spelled as straight chain compound). Many of the simple molecules of organic chemistry, such as the alkanes and alkenes, have both linear and ring isomers, that is, both acyclic and cyclic, with the latter often classified as aromatic. For those with 4 or more carbons, the linear forms can have straight-chain or branched-chain isomers. The lowercase prefix n- denotes the straight-chain isomer; for example, n-butane is straight-chain butane, whereas i-butane is isobutane. Cycloalkanes are isomers of alkenes, not of alkanes, because the ring's closure involves a C-C bond. Having no rings (aromatic or otherwise), all open-chain compounds are aliphatic.

Typically in biochemistry, some isomers are more prevalent than others. For example, in living organisms, the open-chain isomer of glucose usually exists only transiently, in small amounts; D-glucose is the usual isomer; and L-glucose is rare.

Straight-chain molecules are often not literally straight, in the sense that their bond angles are often not 180°, but the name reflects that they are schematically straight. For example, the straight-chain alkanes are wavy or "puckered", as the models below show.

Propane

Propane () is a three-carbon alkane with the molecular formula C3H8. It is a gas at standard temperature and pressure, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used as a fuel. Propane is one of a group of liquefied petroleum gases (LP gases). The others include butane, propylene, butadiene, butylene, isobutylene, and mixtures thereof.

Putrescine

Putrescine, is a foul-smelling organic chemical compound NH2(CH2)4NH2 (1,4-diaminobutane or butanediamine) that is related to cadaverine; both are produced by the breakdown of amino acids in living and dead organisms and both are toxic in large doses. The two compounds are largely responsible for the foul odor of putrefying flesh, but also contribute to the odor of such processes as bad breath and bacterial vaginosis. They are also found in semen and some microalgae, together with related molecules like spermine and spermidine.

Valeric acid

Valeric acid, or pentanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula CH3(CH2)3COOH. Like other low-molecular-weight carboxylic acids, it has a very unpleasant odor. It is found naturally in the perennial flowering plant valerian (Valeriana officinalis), from which it gets its name. Its primary use is in the synthesis of its esters. Salts and esters of valeric acid are known as valerates or pentanoates. Volatile esters of valeric acid tend to have pleasant odors and are used in perfumes and cosmetics. Ethyl valerate and pentyl valerate are used as food additives because of their fruity flavors.

Valeric acid appears similar in structure to GHB and the neurotransmitter GABA in that it is a short-chain carboxylic acid, although it lacks the alcohol and amine functional groups that contribute to the biological activities of GHB and GABA, respectively. It differs from valproic acid simply by lacking a 3-carbon side-chain. Mevalonic acid is derived from valeric acid by methylation and hydroxylation.

Alkali metal hydrides
Alkaline earth hydrides
Group 13 hydrides
Group 14 hydrides
Pnictogen hydrides
Hydrogen chalcogenides
Hydrogen halides
Transition metal hydrides
Lanthanide hydrides
Actinide hydrides
Alcohols
Barbiturates
Benzodiazepines
Carbamates
Flavonoids
Imidazoles
Kava constituents
Monoureides
Neuroactive steroids
Nonbenzodiazepines
Phenols
Piperidinediones
Pyrazolopyridines
Quinazolinones
Volatiles/gases
Others/unsorted

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