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Ethylene
Ethylene Ethylene
General
Molecular formula C2H4
SMILES C=C
Molar mass 28. A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 05 g/mol
Appearance colourless gas
CAS number [74-85-1]
Properties
Density and phase 1. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties 178 kg/m³ at 15 °C, gas [1]
Solubility in water 3. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as 5 mg/100 ml (17 °C)
Melting point −169. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 2 °C (104. 0 K, -272. 6 °F)
Boiling point −103. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 7 °C (169. 5 K, -154. 7 °F)
pKa 44
Critical point 282. In Physical chemistry, Thermodynamics, Chemistry and Condensed matter physics, a critical point, also called a critical state 4 K (9. 2 °C)
at 5. 04 MPa (50 atm)
Std enthalpy of
formation ΔfH°gas		 +52. The standard enthalpy of formation or "standard heat of formation" of a compound is the change of Enthalpy that accompanies the formation of 1 mole of a 47 kJ/mol
Standard molar
entropy S°gas		 219. In Chemistry, the standard molar entropy is the Entropy content of one mole of substance under standard conditions (not standard temperature and pressure 32 J·K−1·mol−1
Structure
Symmetry group D2h
Dipole moment Zero
Hazards
MSDS External MSDS
EU classification Extremely flammable (F+)
NFPA 704
4
1
2
 
Supplementary data page
Structure and
properties
Thermodynamic
data
Spectral data UV, IR, NMR, MS
Related compounds
Related compounds Ethane
Acetylene
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Ethylene (or IUPAC name ethene) is the chemical compound with the formula C2H4. The Symmetry group of an object ( Image, signal, etc eg in 1D 2D or 3D is the group of all Isometries under which it is In physics there are two kinds of dipoles ( Hellènic: di(s- = two- and pòla = pivot hinge An electric dipole is a A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance and save the page --> This page provides supplementary chemical data on Methane. Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating This page provides supplementary chemical data on Ethylene. Structure and properties This page provides supplementary chemical data on Ethylene. Structure and properties This page provides supplementary chemical data on Ethylene. Structure and properties This page provides supplementary chemical data on Ethylene. Structure and properties Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry ( UV/ VIS) involves the Spectroscopy of Photons in the UV-visible Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is the name given to a technique which exploits the magnetic properties of certain nuclei Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles ETHANE is a mnemonic indicating a protocol used by Emergency services to report situations which they may be faced with especially as it relates to major incidents where Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. It is the simplest alkene. In Organic chemistry, an alkene, olefin, or olefine is an unsaturated Chemical compound containing at least one Carbon Because it contains a double bond, ethylene is called an unsaturated hydrocarbon or an olefin. It is extremely important in industry and even has a role in biology as a hormone. Hormones (from Greek ὁρμή - "impetus" are chemicals released by cells that affect cells in other parts of the body [2] Ethylene is the most produced organic compound in the world; global production of ethylene exceeded 75 million metric tonnes per year in 2005. An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon. [3] To meet the ever increasing demand for ethylene, sharp increases in production facilities have been added globally, particularly in the Gulf countries. The Arab states of the Persian Gulf are made of the kingdoms of Bahrain and Saudi Arabia, the Sultanate of Oman, the States A structure of ethylene also appears in the introduction of a popular anime, The Melancholy of Haruhi Suzumiya, marking its enduring impact on international culture . is the name of the 2006 television Anime about a girl who unbeknownst to her possesses the power to change reality.

Contents

Structure

This hydrocarbon has four hydrogen atoms bound to a pair of carbon atoms that are connected by a double bond. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 All six atoms that comprise ethylene are coplanar. In Geometry, a set of points in space is coplanar if the points all lie in the same geometric plane. The H-C-H angle is 117°, close to the 120°. In Geometry and Trigonometry, an angle (in full plane angle) is the figure formed by two rays sharing a common Endpoint, called for ideal sp² hybridized carbon. -->In Chemistry The molecule is also relatively rigid: rotation about the C-C bond is a high energy process that requires breaking the π-bond, while retaining the σ-bond between the carbon atoms.

The double bond is a region of high electron density, and most reactions occur at this double bond position. Electron density is the measure of the Probability of an Electron being present at a specific location

History

From 1795 on, ethylene was referred to as the olefiant gas (oil-making gas), because it combined with chlorine to produce the oil of the Dutch (1,2-dichloroethane). Year 1795 ( MDCCXCV) was a Common year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and Ethylene was first synthesized in 1795 by a collaboration of four Dutch chemists. The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands

In the mid-19th century, the suffix -ene (an Ancient Greek root added to the end of female names meaning "daughter of") was widely used to refer to a molecule or part thereof that contained one fewer hydrogen atoms than the molecule being modified. Thus, ethylene (C2H4) was the "daughter of ethyl" (C2H5). The name ethylene was used in this sense as early as 1852. Year 1852 ( MDCCCLII) was a Leap year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Leap year

In 1866, the German chemist August Wilhelm von Hofmann proposed a system of hydrocarbon nomenclature in which the suffixes -ane, -ene, -ine, -one, and -une were used to denote the hydrocarbons with 0, 2, 4, 6, and 8 fewer hydrogens than their parent alkane. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. August Wilhelm von Hofmann ( April 8, 1818 &ndash May 5, 1892) was a German Chemist. Alkanes, also known as Paraffins are Chemical compounds that consist only of the elements Carbon (C and Hydrogen (H (i [4] In this system, ethylene became ethene. Hofmann's system eventually became the basis for the Geneva nomenclature approved by the International Congress of Chemists in 1892, which remains at the core of the IUPAC nomenclature. Year 1892 ( MDCCCXCII) was a Leap year starting on Friday (link will display the full calendar of the Gregorian Calendar (or a Leap year The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization However, by that time, the name ethylene was deeply entrenched, and it remains in wide use today, especially in the chemical industry.

The 1979 IUPAC nomenclature rules made an exception for retaining the non-systematic name ethylene[5], however, this decision was reversed in the 1993 rules[6] so the correct name is now ethene.

Uses

Approximately 80% of ethylene used in the United States and Europe is used to create ethylene oxide, ethylene dichloride, and polyethylene. The United States of America —commonly referred to as the Polyethylene or polythene ( IUPAC name poly(ethene) is a Thermoplastic commodity heavily used in consumer products (notably the [7] In smaller quantities, ethylene is used as an anesthetic agent (in an 85% ethylene/15% oxygen ratio), to hasten fruit ripening, as well as a welding gas. Anesthesia, or anaesthesia (see spelling differences; from Greek grc αν- an-, "without" and grc αἲσθησις [8][7]

Polyethylenes of various density and melt flow account for more than 50% of world ethylene demand. The primary use of polyethylene is in film applications for packaging, carrier bags and trash liners. Packaging is the science art and technology of enclosing or protecting products for distribution storage sale and use Plastic shopping bags, or carrier bags or plastic grocery bags are a common type of Shopping bag in several countries Other applications include injection moulding, pipe extrusion, wire and cable sheathing and insulation, as well as extrusion coating of paper and cardboard. Injection molding (British moulding

Ethylene derivatives include: ethylene oxide, styrene monomer (via ethyl benzene) and linear higher olefins. Styrene, also known as vinyl benzene as well as many other names (see table is an Organic compound with the Chemical formula C6H5CH=CH2 Ethylbenzene is an Organic compound with the formula C6H5CH2CH3 In Organic chemistry, an alkene, olefin, or olefine is an unsaturated Chemical compound containing at least one Carbon [7]

Ethylene oxide is a key raw material in the production of surfactants and detergents. Surfactants are wetting agents that lower the Surface tension of a liquid allowing easier spreading and lower the Interfacial tension between two liquids A detergent (as a noun is a material intended to assist Cleaning. It is also used to manufacture ethylene glycols, which are in turn used in soft drinks and food packaging and textiles, and to make ethylene oxide glycol ether solvents. Ethylene glycol ( monoethylene glycol ( MEG) 12-ethanediol, IUPAC name: ethane-12-diol) is an Alcohol with two -OH

Styrene monomer is used principally in polystyrene for packaging and insulation, as well as in styrene butadiene rubber for tires and footwear. Styrene, also known as vinyl benzene as well as many other names (see table is an Organic compound with the Chemical formula C6H5CH=CH2 Polystyrene ˌpɒliˈstaɪriːn ( IUPAC Polyphenylethene is an aromatic Polymer made from the aromatic Monomer Styrene

Linear higher olefins are used as base materials for the manufacture of detergents, plasticisers, synthetic lubricants and additives, but also as co-monomers in the production of polyethylenes. A detergent (as a noun is a material intended to assist Cleaning. Plasticizers are additives that increase the Plasticity or Fluidity of the material to which they are added these include plastics cement concrete wallboard and Synthetic oil is Oil consisting of Chemical compounds which were not originally present in Crude oil ( Petroleum) but were Artificially [7]

Production

Ethylene is produced in the petrochemical industry by steam cracking. Petrochemicals are chemical products made from raw materials of Petroleum or other Hydrocarbon origin In Petroleum geology and Chemistry, cracking is the process whereby complex organic Molecules such as Kerogens or heavy Hydrocarbons In this process, gaseous or light liquid hydrocarbons are heated to 750–950 °C, inducing numerous free radical reactions followed by immediate quench to freeze the reactions. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called This process converts large hydrocarbons into smaller ones and introduces unsaturation. Ethylene is separated from the resulting complex mixture by repeated compression and distillation. Physical compression is the result of the subjection of a material to Compressive stress, resulting in reduction of Volume. Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture In a related process used in oil refineries, high molecular weight hydrocarbons are cracked over zeolite catalysts. Zeolites (Greek zein, "to boil" lithos, "a stone" are hydrated Aluminosilicate Minerals and have a micro-porous structure Heavier feedstocks, such as naphtha and gas oils require at least two "quench towers" downstream of the cracking furnaces to recirculate pyrolysis-derived gasoline and process water. When cracking a mixture of ethane and propane, only one water quench tower is required. [9]

The areas of an ethylene plant are:

  1. steam cracking furnaces;
  2. primary and secondary heat recovery with quench;
  3. a dilution steam recycle system between the furnaces and the quench system;
  4. primary compression of the cracked gas (3 stages of compression);
  5. hydrogen sulfide and carbon dioxide removal (acid gas removal);
  6. secondary compression (1 or 2 stages);
  7. drying of the cracked gas;
  8. cryogenic treatment;
  9. all of the cold cracked gas stream goes to the demethanizer tower. The overhead stream from the demethanizer tower consists of all the hydrogen and methane that was in the cracked gas stream. Different methods of cryogenically treating this overhead stream results in the separation of the hydrogen and the methane. This usually involves liquid methane at a temperature around -250 degrees F. Complete recovery of all the methane is critical to the economical operation of an ethylene plant. Often one or two Turboexpanders are used for Methane recovery from the demethanizer overhead stream. A turboexpander, also referred to as a turbo-expander or an expansion turbine, is a centrifugal or axial flow Turbine through which a high Pressure Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas.
  10. the bottom stream from the demethanizer tower goes to the deethanizer tower. The overhead stream from the deethanizer tower consists of all the C2,'s that were in the cracked gas stream. The C2's then go to a C2 splitter. The product ethylene is taken from the overhead of the tower and the ethane coming from the bottom of the splitter is recycled to the furnaces to be cracked again;
  11. the bottom stream from the deethanizer tower goes to the depropanizer tower. The overhead stream from the depropanizer tower consists of all the C3's that were in the cracked gas stream. Prior to sending the C3's to the C3 splitter this stream is hydrogenated in order to react out the methylacetylene and propadiene. Then this stream is sent to the C3 splitter. The overhead stream from the C3 splitter is product propylene and the bottom stream from the C3 splitter is propane which can be sent back to the furnaces for cracking or used as fuel.
  12. The bottom stream from the depropanizer tower is fed to the debutanizer tower. The overhead stream from the debutanizer is all of the C4's that was in the cracked gas stream. The bottom stream from the debutanizer consists of everything in the cracked gas stream that is C5 or heavier. This could be called a light pyrolysis gasoline. [9]

Since the production of ethylene is energy intensive, much effort has been dedicated recovering heat from the gas leaving the furnaces. Most of the energy recovered from the cracked gas is used to make high pressure (1200 psig) steam. This steam is in turn used to drive the turbines for compressing cracked gas, the propylene refrigeration compressor, and the ethylene refrigeration compressor. An ethylene plant, once running, does not need to import any steam to drive its steam turbines. A typical world scale ethylene plant (about 1. 5 billion pounds of ethylene per year) uses a 45,000 horsepower cracked gas compressor, a 30,000 horsepower propylene compressor, and a 15,000 horsepower ethylene compressor.

When starting an ethylene plant it is important to start the cooling systems in the proper order. The cooling systems consist of Cooling Tower Water (CTW); propylene refrigeration with four or five different levels or stages. Each level corresponds to a particular pressure and temperature; and three or four stages of ethylene regfrigeration. The CTW must be started first because the propylene system needs it to condense propylene and the ethylene refrigeration systems needs it to desuperheat high pressure ethylene. The propylene system must start next because the ethylene system needs high pressure propylene for desuperheating the high pressure ethylene stage and the low pressure propylene stage for condensing the high pressure ethylene. While the ethylene plant is running, the plant can continue to run for a time if the ethylene refrigeration compressor shuts down. However, if the propylene compressor shuts down the whole plant must be shut down immediately. [9]

Laboratory preparation

Ethylene can be conveniently produced in the laboratory by distilling absolute ethanol with an excess of concentrated sulfuric acid and washing the distillate vapor stream in an aqueous solution of sodium hydroxide to remove the sulfur dioxide contaminant. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature [10]

Peculiarity of spectrum

Although ethylene is a relatively simple molecule, its spectrum[11] is considered to be one of the most difficult to explain adequately from both a theoretical and practical perspective. Spectroscopy was originally the study of the interaction between Radiation and Matter as a function of Wavelength (λ For this reason, it is often used as a test case in computational chemistry. Computational chemistry is a branch of Chemistry that uses computers to assist in solving chemical problems Of particular note is the difficulty in characterizing the ultraviolet absorption of the molecule. Interest in the subtleties and details of the ethylene spectrum can be dated back to at least the 1950s.

Chemical reactions

Ethylene is an extremely important building block in the petrochemical industry. It can undergo many types of reactions which leads to a plethora of major chemical products. A list of some major types of reactions includes, 1) Polymerization, 2) Oxidation, 3) Halogenation and Hydrohalogenation, 4) Alkylation, 5) Hydration, 6) Oligomerization, 7) Oxo-reaction, and 8) a ripening agent for fruits and vegetables (see Physiological responses of plants). In Polymer chemistry, polymerization is a process of reacting Monomer Molecules together in a Chemical reaction to form three-dimensional networks Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state "Fluorination" redirects here For the addition of fluoride to drinking water see Water fluoridation. A hydrohalogenation reaction is the Electrophilic addition of Hydrohalic acids like Hydrogen chloride or Hydrogen bromide to Alkenes Alkylation is the transfer of an Alkyl group from one Molecule to another In Chemistry, an oligomer consists of a limited number of Monomer units (ολιγος or oligos is Greek for "a few" in contrast to a Hydroformylation, also known as oxo synthesis, is an important industrial process for the production of aldehydes from alkenes [9]

Additions to double bond

Like most alkenes, ethylene reacts with halogens to produce halogenated hydrocarbons1,2-C2H4X2. Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions It can also react with water to produce ethanol, but the rate at which this happens is very slow unless a suitable catalyst, such as phosphoric or sulfuric acid, is used. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Phosphoric acid, also known as orthophosphoric acid or phosphoric(V acid, is a mineral (inorganic acid having the Chemical formula Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. Under high pressure, and, in the presence of a catalytic metal (platinum, rhodium, nickel), hydrogen will react with ethylene to form ethane. Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Rh redirects here For other uses see Rh (disambiguation Rhodium (ˈroʊdiəm is a Chemical element with the symbol Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 ETHANE is a mnemonic indicating a protocol used by Emergency services to report situations which they may be faced with especially as it relates to major incidents where

Ethylene is used primarily as an intermediate in the manufacture of other chemicals in the synthesis of monomers. A monomer (from Greek mono "one" and meros "part" is a small Molecule that may become chemically bonded to other Ethylene can be chlorinated to produce 1,2-dichloroethane (ethylene dichloride). Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and This can be converted to vinyl chloride, the monomer precursor to plastic polyvinyl chloride, or combined with benzene to produce ethylbenzene, which is used in the manufacture of polystyrene, another important plastic. Vinyl chloride is the Organic compound with the formula CH2CHCl Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 Ethylbenzene is an Organic compound with the formula C6H5CH2CH3 Polystyrene ˌpɒliˈstaɪriːn ( IUPAC Polyphenylethene is an aromatic Polymer made from the aromatic Monomer Styrene

Ethylene is more reactive than alkanes because of two reasons:

1. It has a double bond, one called the π-bond(pi) and one called the σ-bond (sigma), where the π-bond is weak and the σ-bond is strong. The presence of the π-bond makes it a high energy molecule. Thus bromine water decolourises readily when it is added to ethylene.

2. High electron density at the double bond makes it react readily. It is broken in an addition reaction to produce many useful products. An addition reaction, in Chemistry, is in its simplest terms an Organic reaction where two or more molecules combine to form a larger one

Polymerization

Main article: Polyethylene

Ethylene polymerizes to produce polyethylene, also called polyethene or polythene, the world's most widely-used plastic. Polyethylene or polythene ( IUPAC name poly(ethene) is a Thermoplastic commodity heavily used in consumer products (notably the A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds Polyethylene or polythene ( IUPAC name poly(ethene) is a Thermoplastic commodity heavily used in consumer products (notably the

Major polyethylene product groups are low density polyethylene, high density polyethylene, polyethylene copolymers, as well as ethylene-propylene co- & terpolymers. [9]

See also: Ziegler-Natta catalyst

Oxidation

Ethylene is oxidized to produce ethylene oxide, which is hydrolysed to ethylene glycol. A Ziegler-Natta catalyst is a Reagent or a mixture of reagents used in the production of Polymers of 1-alkenes (α-olefins Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions Ethylene glycol ( monoethylene glycol ( MEG) 12-ethanediol, IUPAC name: ethane-12-diol) is an Alcohol with two -OH It is also a precursor to vinyl acetate. Vinyl acetate is an Organic compound with the formula CH3COOCH=CH2

Main article: Wacker process

Ethylene undergoes oxidation by palladium to give acetaldehyde. The Wacker process or the Hoechst-Wacker process (named after the chemical companies of the same name originally referred to the oxidation of Ethylene to Acetaldehyde Acetaldehyde, sometimes known as ethanal, is an organic chemical compound with the formula C[[Hydrogen H]]3CH O or MeCHO This conversion was at one time a major industrial process. [12] The process proceeds via the initial complexation of ethylene to a Pd(II) center.

Major intermediates of the oxidation of Ethylene are ethylene oxide, acetaldehyde, vinyl acetate and ethylene glycol. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Acetaldehyde, sometimes known as ethanal, is an organic chemical compound with the formula C[[Hydrogen H]]3CH O or MeCHO Vinyl acetate is an Organic compound with the formula CH3COOCH=CH2 Ethylene glycol ( monoethylene glycol ( MEG) 12-ethanediol, IUPAC name: ethane-12-diol) is an Alcohol with two -OH The list of products made from these intermediates is long. Some of them are: polyesters, polyurethane, morpholine, ethanolamines, aspirin and glycol ethers. Polyester is a category of Polymers which contain the Ester Functional group in their main chain A polyurethane, commonly abbreviated PU, is any Polymer consisting of a chain of organic units joined by urethane links Morpholine is an organic Chemical compound having the Chemical formula O ( C[[hydrogen H]]2CH22 Ethanolamine, also called 2-aminoethanol or monoethanolamine (often abbreviated as ETA or MEA) is an Organic chemical compound Aspirin, or acetylsalicylic acid (ASA (əˌsɛtɨlsælɨˌsɪlɨk ˈæsɨd is a Salicylate drug, often used as an Analgesic to relieve Glycol ethers are a group of Solvents based on Alkyl Ethers of Ethylene glycol commonly used in Paints These solvents typically have [9]

Halogenation and hydrohalogenation

Major intermediates from the halogenation and hydrohalogenation of ethylene include: ethylene dichloride, ethyl chloride and ethylene dibromide. "Fluorination" redirects here For the addition of fluoride to drinking water see Water fluoridation. A hydrohalogenation reaction is the Electrophilic addition of Hydrohalic acids like Hydrogen chloride or Hydrogen bromide to Alkenes Chloroethane or monochloroethane, commonly known by its old name ethyl chloride, is a Chemical compound once widely used in producing Tetra-ethyl lead Some products in this group are: polyvinyl chloride, trichloroethylene, perchloroethylene, methyl chloroform, polyvinylidiene chloride and copolymers, and ethyl bromide. The Chemical compound trichloroethylene is a chlorinated Hydrocarbon commonly used as an industrial Solvent. Tetrachloroethylene, also known under its systematic name tetrachloroethene and as perchloroethylene, perchloroethene, perc, and PCE Polyvinylidene chloride is a Polymer derived from Vinylidene chloride. A heteropolymer or copolymer is a Polymer derived from two (or more Monomeric species as opposed to a Homopolymer where only one monomer is Bromoethane, also known as ethyl bromide is a Chemical compound of the Haloalkanes group [9]

Alkylation

Major chemical intermediates from the alkylation of ethylene include: ethylbenzene, ethyl toluene, ethyl anilines, 1,4-hexadiene and aluminium alkyls. Alkylation is the transfer of an Alkyl group from one Molecule to another Ethylbenzene is an Organic compound with the formula C6H5CH2CH3 Toluene, also known as methylbenzene or phenylmethane, is a clear water -insoluble liquid with the typical smell of Paint thinners redolent of WikipediaNaming Products of these intermediates include polystyrene, unsaturated polyesters and ethylene-propylene terpolymers. Polystyrene ˌpɒliˈstaɪriːn ( IUPAC Polyphenylethene is an aromatic Polymer made from the aromatic Monomer Styrene Polyester is a category of Polymers which contain the Ester Functional group in their main chain A heteropolymer or copolymer is a Polymer derived from two (or more Monomeric species as opposed to a Homopolymer where only one monomer is [9]

Hydration

Ethanol is the primary intermediate of the hydration of ethylene. Important products from ethanol are: ethylamines, acetaldehyde, and ethyl acetate. Ethylamine is a Chemical compound with the formula CH3CH2NH2 It has a strong Ammonia -like odor Acetaldehyde, sometimes known as ethanal, is an organic chemical compound with the formula C[[Hydrogen H]]3CH O or MeCHO Ethyl acetate ( systematically, ethyl ethanoate commonly abbreviated EtOAc or EA is the Organic compound with the formula CH3COOCH2CH3 [9]

Oligomerization

The primary products of the Oligomerization of ethylene are alpha-olefins and linear primary alcohols. In Chemistry, an oligomer consists of a limited number of Monomer units (ολιγος or oligos is Greek for "a few" in contrast to a Alpha-olefins (or α-olefins) are a family of Organic compounds which are Olefins or Alkenes with a Chemical formula C In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon These are used as plasticizers and surfactants. Plasticizers are additives that increase the Plasticity or Fluidity of the material to which they are added these include plastics cement concrete wallboard and Surfactants are wetting agents that lower the Surface tension of a liquid allowing easier spreading and lower the Interfacial tension between two liquids [9]

Oxo-reaction

The Oxo-reaction of ethylene results in propionaldehyde with its primary products of propionic acid and n-propyl alcohol. Hydroformylation, also known as oxo synthesis, is an important industrial process for the production of aldehydes from alkenes Propionaldehyde or propanal is the Organic compound with the formula CH3CH2CHO Propionic acid (systematically named propanoic acid) is a naturally-occurring Carboxylic acid with Chemical formula C[[Hydrogen H]]3CH2C Propan-1-ol is a primary Alcohol with the formula CH3CH2CH2OH [9]

In the synthesis of fine chemicals

Ethylene is useful in organic synthesis. Organic synthesis is a special branch of Chemical synthesis and is concerned with the construction of Organic compounds via Organic reactions Organic [13] Representative reactions include Diels-Alder additions, ene reaction, and arene alkylation. The Diels-Alder reaction is an Organic chemical reaction (specifically a Cycloaddition) between a conjugated Diene and a substituted Alkene, The Ene reaction (also known as the Alder-ene reaction) is a Chemical reaction between an Alkene with an Allylic Hydrogen (the

Miscellaneous

Ethylene is found in many lip gloss products.

Production of ethylene in mineral oil-filled transformers is a key indicator of severe localized overheating (>750 degrees C). Mineral oil or liquid Petroleum is a By-product in the Distillation of Petroleum to produce Gasoline and other petroleum [14]

Ethylene as a plant hormone

Ethylene acts physiologically as a hormone in plants. Plant hormones (also known as phytohormones) are chemicals that regulate plant growth Plants are living Organisms belonging to the kingdom Plantae. [15][16] It exists as a gas and acts at trace levels throughout the life of the plant by stimulating or regulating the ripening of fruit, the opening of flowers, and the abscission (or shedding) of leaves. Ripening is a process in Fruits that causes them to become more Edible. The term fruit has different meanings dependent on context and the term is not synonymous in Food preparation and Biology. A flower, also known as a bloom or Blossom, is the reproductive structure found in Flowering plants (plants of the division Magnoliophyta, also Abscission (from Latin abscindere from ab- ‘off away’ + scindere ‘to cut’ is the shedding of a body part In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. Its biosynthesis starts from methionine with 1-aminocyclopropane-1-carboxylic acid (ACC) as a key intermediate. Methionine ( abbreviated as Met or M) is an α- Amino acid with the Chemical formula HO2CCH(NH2CH2CH2SCH3

History of ethylene in plant biology

Ethylene has been used in practice since the ancient Africans, who would gash figs in order to stimulate ripening (wounding stimulates ethylene production by plant tissues). The ancient Chinese would burn incense in closed rooms to enhance the ripening of pears. Incense is composed of Aromatic biotic materials It releases fragrant Smoke when burned In 1864, it was discovered that gas leaks from street lights led to stunting of growth, twisting of plants, and abnormal thickening of stems (Arteca, 1996; Salisbury and Ross, 1992). In 1901, a Russian scientist named Dimitry Neljubow showed that the active component was ethylene [17] . Doubt discovered that ethylene stimulated abscission in 1917 (Doubt, 1917). Abscission (from Latin abscindere from ab- ‘off away’ + scindere ‘to cut’ is the shedding of a body part It wasn't until 1934 that Gane reported that plants synthesize ethylene (Gane, 1934). In 1935, Crocker proposed that ethylene was the plant hormone responsible for fruit ripening as well as inhibition of vegetative tissues, such as the dropping of leaves (Crocker, 1935).

Ethylene biosynthesis in plants

Plant biosynthesis of ethylene
Plant biosynthesis of ethylene

It has been shown that ethylene is produced from essentially all parts of higher plants, including leaves, stems, roots, flowers, fruits, tubers, and seedlings.

"Ethylene production is regulated by a variety of developmental and environmental factors. During the life of the plant, ethylene production is induced during certain stages of growth such as germination, ripening of fruits, abscission of leaves, and senescence of flowers. Ethylene production can also be induced by a variety of external aspects such as mechanical wounding, environmental stresses, and certain chemicals including auxin and other regulators"[18]

The biosynsthesis of the hormone starts with conversion of the amino acid methionine to S-adenosyl-L-methionine (SAM, also called Adomet) by the enzyme Met Adenosyltransferase. SAM is then converted to 1-aminocyclopropane-1-carboxylic-acid (ACC) by the enzyme ACC synthase (ACS); the activity of ACS is the rate-limiting step in ethylene production, therefore regulation of this enzyme is key for the ethylene biosynthesis. The final step requires oxygen and involves the action of the enzyme ACC-oxidase (ACO), formerly known as the Ethylene Forming Enzyme (EFE). Ethylene biosynthesis can be induced by endogenous or exogenous ethylene. ACC synthesis increases with high levels of auxins, specially Indole Acetic Acid (IAA), and cytokinins. ACC synthase is inhibited by abscisic acid.

Ethylene perception in plants

Ethylene could be perceived by a transmembrane protein dimer complex. A dimer is a Chemical or Biological entity consisting of two subunits called Monomers which are held together by either Intramolecular forces The first gene encoding an ethylene receptor was first cloned from Arabidopsis thaliana by Caren Chang, Elliot Meyerowitz and colleagues at the California Institute of Technology[19] and then in tomato by Jack Wilkinson, Harry Klee and colleagues at the Monsanto Company[20]. Arabidopsis thaliana ( A-ra-bi-dóp-sis tha-li-á-na; thale cress, mouse-ear cress or Arabidopsis) is a small The California Institute of Technology (commonly referred to as Caltech) is a private, Coeducational research university located in Pasadena The tomato ( Solanum lycopersicum, syn Lycopersicon lycopersicum) is a herbaceous usually sprawling plant in the Solanaceae or nightshade family The Monsanto Company ( is a multinational Agricultural biotechnology Corporation. Ethylene receptors are encoded by multiple genes in the Arabidopsis and tomato genomes. In classical genetics the genome of a Diploid Organism including Eukarya refers to a full set of chromosomes or genes in a Gamete, thereby The gene family is comprised of five receptors in Arabidopsis and at least six in tomato, most of which have been shown to bind ethylene. A gene family is a set of Genes with a known homology. They are generally biochemically similar DNA sequences for ethylene receptors have also been identified in many other plant species and an ethylene binding protein has even been identified in Cyanobacteria[21]

Environmental and biological triggers of ethylene

Environmental cues can induce the biosynthesis of the plant hormone. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of Bacteria that obtain their energy Flooding, drought, chilling, wounding, and pathogen attack can induce ethylene formation in the plant.

In flooding, root suffers from lack of oxygen, or anoxia, which leads to the synthesis of 1-Aminocyclopropane-1-carboxylic acid (ACC). For other uses of the term "hypoxia" see Hypoxia. Hypoxia or oxygen depletion is a phenomenon that occurs in aquatic environments ACC is transported upwards in the plant and then oxidized in leaves. The product, the ethylene causes epinasty of the leaves.

One speculation recently put forth for epinasty is the downard pointing leaves may act as pump handles in the wind. The ethylene may or may not additionally induce the growth of a valve in the xylem, but the idea would be that the plant would harness the power of the wind to pump out more water from the roots of the plants than would normally happen with transpiration. In Vascular plants xylem is one of the two types of transport tissue Phloem being the other Transpiration is the Evaporation of water from the aerial parts of Plants especially leaves but also stems Flowers and Roots

Physiological responses of plants

Like the other plant hormones, ethylene is considered to have pleiotropic effects. Pleiotropy occurs when a single Gene influences multiple phenotypic traits Consequently a new Mutation in the gene will have an effect on all This essentially means that it is thought that at least some of the effects of the hormone are unrelated. What is actually caused by the gas may depend on the tissue affected as well as environmental conditions. In the evolution of plants, ethylene would simply be a message that was coopted for unrelated uses by plants during different periods of the evolutionary development.

List of Plant Responses to Ethylene

Commercial Issues

Ethylene shortens the shelf life of many fruits by hastening fruit ripening and floral senescence. Auxins are a class of Plant growth substance (often called Phytohormone or Plant hormone) Cytokinins (CK are a class of Plant growth substances ( Plant Hormones that promote Cell division. In Vascular plants xylem is one of the two types of transport tissue Phloem being the other Auxins are a class of Plant growth substance (often called Phytohormone or Plant hormone) In Botany, a stoma (also stomate; plural stomata) is a tiny opening or pore found mostly on the underside of a Plant Leaf Pineapple ( Ananas comosus) is the common name for an edible Tropical Plant and also its Fruit It is native to the southern part of Brazil Ripening is a process in Fruits that causes them to become more Edible. Tomatoes, bananas, and apples will ripen faster in the presence of ethylene. The tomato ( Solanum lycopersicum, syn Lycopersicon lycopersicum) is a herbaceous usually sprawling plant in the Solanaceae or nightshade family For the fruit see Banana. For other meanings see Banana (disambiguation. The apple is the pomaceous Fruit of the apple tree Species Malus domestica in the Rose family Rosaceae. Bananas placed next to other fruits will produce enough ethylene to cause accelerated fruit ripening. Ethylene will shorten the shelf life of cut flowers and potted plants by accelerating floral senescence and floral abscission. Abscission (from Latin abscindere from ab- ‘off away’ + scindere ‘to cut’ is the shedding of a body part Flowers and plants which are subjected to stress during shipping, handling, or storage produce ethylene causing a significant reduction in floral display. Flowers affected by ethylene include carnation, geranium, petunia, rose, and many others[22]. Gardeners often use the name "geranium" to mean Pelargonium: see below. For Petunia Pig, a Looney Tunes character see Petunia Pig For Aunt Petunia see Aunt Petunia For A rose is a perennial flowering Shrub or vine of the Genus Rosa, within the family Rosaceae, that contains over 100 species

Ethylene can cause significant economic losses for florists, markets, suppliers, and growers. Researchers have come up with several ways to inhibit ethylene, including inhibiting ethylene synthesis and inhibiting ethylene perception. Inhibiting ethylene synthesis is less effective for reducing post-harvest losses since ethylene from other sources can still have an effect. By inhibiting ethylene perception, fruits, plants and flowers don't respond to ethylene produced endogenously or from exogenous sources. Inhibitors of ethylene perception include compounds that have a similar shape to ethylene, but do not elicit the ethylene response. An example of an ethylene perception inhibitor is 1-methylcyclopropene (1-MCP).

Commercial growers of bromeliads, including pineapple plants, use ethylene to induce flowering. Pineapple ( Ananas comosus) is the common name for an edible Tropical Plant and also its Fruit It is native to the southern part of Brazil Plants can be induced to flower either be treated with the gas in a chamber or by placing a banana peel next to the plant in an enclosed area. For the fruit see Banana. For other meanings see Banana (disambiguation.

Effects upon humans

Depending on the concentration, ethylene gas can cause a pleasant odor, euphoria, nausea, hyperglycemia, a variety of psychological effects, blood pressure changes, hypoxia, loss of consciousness, or death. Nausea ( Latin: Nausea, Greek:, " Sea-sickness " also called wamble) is the sensation of unease and discomfort Hyperglycemia, hyperglycaemia, or high blood sugar is a condition in which an excessive amount of Glucose circulates in the Blood plasma Blood pressure is also the title of a short story by Damon Runyan in Guys and Dolls and Other Stories Chronic Hypoxia is a pathological condition in which the body as a whole ( generalized hypoxia) or region of the body ( tissue hypoxia) is deprived of adequate

Symptoms

Ethylene has a pleasant sweet faint odor, and has a slightly sweet taste, and as it enhances fruit ripening, assists in the development of odour-active aroma volatiles (especially esters), which are responsible for the specific smell of each kind of flower or fruit. Esters are a class of Chemical compounds and Functional groups Esters consist of an inorganic or organic Acid in which at least

In mild doses, ethylene produces states of euphoria, associated with stimulus to the pleasure centers of the human brain.

Exposure at 37. 5% for 15 minutes may result in marked memory disturbances. Humans exposed to as much as 50% ethylene in air, whereby the oxygen availability is decreased to 10%, experience a complete loss of consciousness and may subsequently die due to hypoxia. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Chronic Hypoxia is a pathological condition in which the body as a whole ( generalized hypoxia) or region of the body ( tissue hypoxia) is deprived of adequate

Symptoms of ethylene exposure include the following.

Mild exposure in air

Moderate exposure in air

High concentration in air

Very high concentration in air

Severe oxygen deprivation

Very high concentrations in oxygen

Medical and historical use

Ethylene has long been in use as an inhalatory anaesthetic. When used as a surgical anaesthetic, it is always administered with oxygen with an increased risk of fire. In such cases, however, it acts as a simple, rapid anaesthetic having a quick recovery.

Many geologists and scholars believe that the famous Greek Oracle at Delphi (the Pythia) went into her trance-like state as an effect of ethylene rising from ground faults. Delphi ( Greek,) ( pronounce and dialectal forms) is an archaeological site and a modern town in Greece on the south-western PYTHIA is a computer simulation program for particle collisions at very high energies (see Event (particle physics) in Particle accelerators [23]

Safety

There is no evidence to indicate that prolonged exposure to low concentrations of ethylene can result in chronic effects. Prolonged exposure to high concentrations may cause permanent effects because of oxygen deprivation. Prolonged inhalation of about 85% in oxygen (a relatively high concentration) is also slightly toxic, resulting in a slow fall in blood pressure. Blood pressure is also the title of a short story by Damon Runyan in Guys and Dolls and Other Stories At about 94% in oxygen, ethylene is acutely fatal.

It shows little or no carcinogenic or mutagenic properties. Although there may be moderate hyperglycemia, post operative nausea - while higher than nitrous oxide - is less than in the use of cyclopropane. Cyclopropane is a Cycloalkane Molecule with the molecular formula C3H6 consisting of three Carbon Atoms linked to During the induction and early phases, blood pressure may rise a little, but this effect may be due to patient anxiety, as blood pressure quickly returns to normal. Cardiac arrythmias are infrequent and cardio-vascular effects are benign.

See also

References

  1. ^ Record of Ethylene in the GESTIS Substance Database from the BGIA, accessed on 25 October 2007
  2. ^ Wang K, Li H, Ecker J. The BG-Institute for Occupational Safety and Health (German Berufsgenossenschaftliches Institut für Arbeitsschutz, BGIA) is a German institute located in Sankt "Ethylene biosynthesis and signaling networks. ". Plant Cell 14 Suppl: S131-51. PMID 12045274.  
  3. ^ “Production: Growth is the Norm” Chemical and Engineering News, July 1 0, 2006, p. 59.
  4. ^ A. W. Hofmann, LL. D. , F. R. S. . Hofmann's Proposal for Systematic Nomenclature of the Hydrocarbons. www. chem. yale. edu. Retrieved on 2007-01-06. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1066 - Harold Godwinson is crowned King of England. 1205 - Philip of Swabia becomes King
  5. ^ IUPAC nomenclature rule A-3.1 (1979)
  6. ^ Footnote to IUPAC nomenclature rule R-9.1, table 19(b)
  7. ^ a b c d OECD SIDS Initial Assessment Profile - Ethylene. inchem. org. Retrieved on 2008-05-21. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 878 - Syracuse Italy is captured by the Muslim sultan of Sicily.
  8. ^ "Informational Bulletin" (June 1, 1976) 12. California Fresh Market Advisory Board.  
  9. ^ a b c d e f g h i j k Ethylene Keystone to the Petrochemical Industry. Kniel, Ludwig (1980). New York: Marcel Dekker. ISBN 0-8247-6914-7
  10. ^ Julius B. Cohen (1930). Practical Organic Chemistry (preparation 5). Macmillan.  
  11. ^ Ethylene:UV/Visible Spectrum. NIST Webbook. Retrieved on 2006-09-27. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 489 - Odoacer attacks Theodoric at the Battle of Verona and is defeated again
  12. ^ Elschenbroich, C. ;Salzer, A. ”Organometallics : A Concise Introduction” (2nd Ed) (2006) Wiley-VCH: Weinheim. ISBN 3-527-28165-7
  13. ^ Crimmins, M. T. ; Kim-Meade, A. S. "Ethylene" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10. 1002/047084289.
  14. ^ Transformerworld Tutorial No. 3 http://www.transformerworld.co.uk/dga.htm
  15. ^ Chow B, McCourt P (2006). "Plant hormone receptors: perception is everything. ". Genes Dev 20 (15): 1998-2008. doi:10.1101/gad.1432806. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 16882977.  
  16. ^ De Paepe A, Van der Straeten D (2005). "Ethylene biosynthesis and signaling: an overview. ". Vitam Horm 72: 399-430. PMID 16492477.  
  17. ^ Neljubov D. (1901). "Uber die horizontale Nutation der Stengel von Pisum sativum und einiger anderen Pflanzen. ". Beih Bot Zentralbl 10: 128-139.  
  18. ^ Yang, S. F. , and Hoffman N. E. (1984). "Ethylene biosynthesis and its regulation in higher plants". Ann. Rev. Plant Physiol. 35: 155-89. doi:10.1146/annurev.pp.35.060184.001103. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  19. ^ Chang et al. , 1993 Chang C, Kwok SF, Bleecker AB, Meyerowitz EM (1993). "Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators. ". Science 262 (5133): 539-544. PMID 8211181.  
  20. ^ "An ethylene-inducible component of signal transduction encoded by never-ripe. " (1995). Science 270 (5423): 1807-1809. PMID: 8525371.  
  21. ^ Mount SM, Chang C (2002). "Evidence for a plastid origin of plant ethylene receptor genes. ". Plant Physiology 130 (1). PMID: 12226482.  
  22. ^ "Effect of ethylene on flower abscission: a survey. " (2002). Annals of Botany 89 (6): 689-693. PMID: 12102524.  
  23. ^ John Roach. "Delphic Oracle's Lips May Have Been Loosened by Gas Vapors", National Geographic, August 14, 2001.   Retrieved on March 8, 2007

External links

Dictionary

ethylene

-noun

  1. (organic chemistry) The common name for the organic chemical compound ethene. The simplest alkene, a colorless gaseous (at room temperature and pressure) hydrocarbon with the chemical formula C2H4.
  2. (organic chemistry) The divalent radical derived from ethane.
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