"Carbon–hydrogen bond The carbon-hydrogen bond (C–H bond) is a bond between carbon and hydrogen atoms that can be found in many organic compounds. This bond is a covalent bond meaning that carbon shares its outer valence electrons with up to four hydrogens. This completes both of their outer shells making them stable. Carbon–hydrogen bonds have a bond length of about 1.09 Å (1.09 × 10 m) and a bond energy of about 413 kJ/mol (see table below). Using Pauling's scale—C (2.55) and H (2.2)—the electronegativity difference between these two atoms is 0.35. Because of this small difference in electronegativities, the"
"Methyl group A methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms — CH. In formulas, the group is often abbreviated Me. Such hydrocarbon groups occur in many organic compounds. It is a very stable group in most molecules. While the methyl group is usually part of a larger molecule, it can be found on its own in any of three forms: anion, cation or radical. The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed. The methylium cation (CH)"
"for methane in a clathrate is 46 water molecules per unit cell. Methane in solution has a hydration number of 20. In addition to methane, other simple molecules like ethane and carbon dioxide can also form hydrates in these extreme environments. Given the dependence on cold temperatures in keeping the hydrated methane locked away from the atmosphere, anthropogenic climate change has emerged as a possible destabilizing force to the vast reserves of clathrates. Estimates of the amount of methane locked into clathrates range from 500–2500 gigatons of carbon. Due to the flammability of methane gas, methane clathrates can burn creating"
"alcohol. The chemical suffix """"-ane"""" is from the coordinating chemical suffix """"-ine"""" which is from Latin feminine suffix """"-ina"""" which is applied to represent abstracts. The coordination of ""-ane"", ""-ene"", ""-one"", etc. was proposed in 1866 by German chemist August Wilhelm von Hofmann (1818-1892). Methane is a tetrahedral molecule with four equivalent C–H bonds. Its electronic structure is described by four bonding molecular orbitals (MOs) resulting from the overlap of the valence orbitals on C and H. The lowest energy MO is the result of the overlap of the 2s orbital on carbon with the in-phase combination of the 1s"
"the sea or of a lake unless it is bound in place by being formed in or anchored to sediment. One litre of fully saturated methane clathrate solid would therefore contain about 120 grams of methane (or around 169 litres of methane gas at 0 °C and 1 atm), or one cubic metre of methane clathrate releases about 160 cubic metres of gas. Methane forms a structure I hydrate with two dodecahedral (12 vertices, thus 12 water molecules) and six tetradecahedral (14 water molecules) water cages per unit cell. (Because of sharing of water molecules between cages, there are only"
"to a wide range of observed ""formula_21"" and ""formula_22"" values, which has the potential to provide insights into methanogenesis rate and chemical condition in the corresponding environments. Methane clumped isotopes Methane clumped isotopes are methane molecules that contain two or more rare isotopes. Methane (CH) contains two elements, carbon and hydrogen, each of which has two stable isotopes. For carbon, 98.9% are in the form of carbon-12 (C) and 1.1% are carbon-13 (C); while for hydrogen, 99.99% are in the form of protium (H) and 0.01% are deuterium (H or D). Carbon-13 (C) and deuterium (H or D) are rare"
"Methanium In chemistry, methanium is a complex positive ion with formula [], namely a molecule with one carbon atom bonded to three hydrogen atoms and one hydrogen molecule, bearing a +1 electric charge. It is a superacid and one of the onium ions, indeed the simplest carbonium ion. Methanium can be produced in the laboratory as a rarefied gas or as a dilute species in superacids. It was prepared for the first time in 1950 and published in 1952 by Victor Talrose and his assistant Anna Konstantinovna Lyubimova. It occurs as an intermediate species in chemical reactions. The methanium ion"
"Methane clumped isotopes Methane clumped isotopes are methane molecules that contain two or more rare isotopes. Methane (CH) contains two elements, carbon and hydrogen, each of which has two stable isotopes. For carbon, 98.9% are in the form of carbon-12 (C) and 1.1% are carbon-13 (C); while for hydrogen, 99.99% are in the form of protium (H) and 0.01% are deuterium (H or D). Carbon-13 (C) and deuterium (H or D) are rare isotopes in methane molecules. The abundance of the clumped isotopes provides information independent from the traditional carbon or hydrogen isotope composition of methane molecules. Isotopologues are molecules"
"of data for global warming research, along with oxygen and carbon dioxide. Methane hydrates were discovered in Russia in the 1960s, and studies for extracting gas from it emerged at the beginning of the 21st century. The nominal methane clathrate hydrate composition is (CH)(HO), or 1 mole of methane for every 5.75 moles of water, corresponding to 13.4% methane by mass, although the actual composition is dependent on how many methane molecules fit into the various cage structures of the water lattice. The observed density is around 0.9 g/cm, which means that methane hydrate will float to the surface of"
"is a mixture of copper and zinc oxides, supported on alumina, as first used by ICI in 1966. At 5–10 MPa (50–100 atm) and , the reaction is characterized by high selectivity (>99.8%): The production of synthesis gas from methane produces three moles of hydrogen for every mole of carbon monoxide, whereas the synthesis consumes only two moles of hydrogen gas per mole of carbon monoxide. One way of dealing with the excess hydrogen is to inject carbon dioxide into the methanol synthesis reactor, where it, too, reacts to form methanol according to the equation: In terms of mechanism, the"
"rest of the molecule by a triple bond) or to the methylidyne radical ⫶CH (the two atoms as a free molecule with dangling bonds). The name ""methine"" is also widely used in non-systematic nomenclature for the methanetriyl group (IUPAC): a carbon with four single bonds, where one bond is to a hydrogen (>CH−). Every carbon in this molecule is a methine carbon, ""except"" for three; two that are attached to the two nitrogens and not to any hydrogens, and the one attached to the nitrogen, which is attached to two hydrogens (far right). There is a five carbon poly-methine chain"
"Trimethylenemethane Trimethylenemethane (often abbreviated TMM) is a chemical compound with formula . It is a neutral free molecule with two unsatisfied valence bonds, and is therefore a highly reactive free radical. Formally, it can be viewed as an isobutylene molecule with two hydrogen atoms removed from the terminal methyl groups. The electronic structure of trimethylenemethane was discussed in 1948. It is a neutral four-carbon molecule containing four pi molecular orbitals. When trapped in a solid matrix at about 90 K, the six hydrogen atoms of the molecule are equivalent. Thus, it can be described either as zwitterion, or as the"
"in about 1840 by back-formation from ""methylene"", and was then applied to describe ""methyl alcohol"" (which since 1892 is called ""methanol""). ""Methyl"" is the IUPAC nomenclature of organic chemistry term for an alkane (or alkyl) molecule, using the prefix ""meth-"" to indicate the presence of a single carbon. Methyl group A methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms — CH. In formulas, the group is often abbreviated Me. Such hydrocarbon groups occur in many organic compounds. It is a very stable group in most molecules. While the methyl group is"
"that have the same chemical composition, but differ only in their isotopic composition. Methane has ten stable isotopologues: CH, CH, CHD, CHD, CHD, CHD, CHD, CHD, CD and CD, among which, CH is an unsubstituted isotopologue; CH and CHD are singly substituted isotopologues; CHD and CHD are doubly substituted isotopologues. The multiple-substituted isotopologues are clumped isotopologues. The absolute abundance of each isotopologue primarily depends on the traditional carbon and hydrogen isotope compositions (""δ""C and ""δ""D) of the molecules. Clumped isotope composition is calculated relative to the random distribution of carbon and hydrogen isotopes in the methane molecules. The deviations from"
"achieved through the balance of forces between the forces of attraction of nuclei to the plane of the ring of electrons and the forces of mutual repulsion of the nuclei. The Bohr model of the chemical bond took into account the Coulomb repulsion - the electrons in the ring are at the maximum distance from each other. Thus, according to this model, the methane molecule is a regular tetrahedron, in which center the carbon nucleus locates, and in the corners - the nucleus of hydrogen. Chemical bond between them form four two-electron rings, rotating around the lines connecting the center"
"in catalysts that facilitate C–H bond activation in methane (and other lower numbered alkanes). Methane's heat of combustion is 55.5 MJ/kg. Combustion of methane is a multiple step reaction summarized as follows: Peters four-step chemistry is a systematically reduced four-step chemistry which explains the burning of methane. Given appropriate conditions, methane reacts with as follows: where X is a halogen: fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). This mechanism for this process is called free radical halogenation. It is initiated when UV light or some other radical initiator produces a halogen atom. A two-step chain reaction ensues in"
"in the center of this molecule. Methine group In chemistry, methine is a trivalent functional group =CH−, derived formally from methane. It consists of a carbon atom bound by two single bonds and one double bond, where one of the single bonds is to a hydrogen. The group is also called methyne or methene; its IUPAC systematic name is methylylidene or methanylylidene This name is also used for each carbon-hydrogen subunit of an aromatic compound, although the latter do not have discrete single and double bonds. This group is sometimes called ""methylidyne"", however that name belongs properly to either the"
"very strong acids, such as fluoroantimonic acid (antimony pentafluoride in hydrogen fluoride HF). At about 2 Torr of pressure and ambient temperature, the methane ion will react with neutral methane to yield methanium and a methyl radical: The cations obtained by reaction of methane with + HF are stabilized by interactions with the HF molecules. At low pressures (around 1 mmHg) and ambient temperatures, methanium is unreactive towards neutral methane. Methanium In chemistry, methanium is a complex positive ion with formula [], namely a molecule with one carbon atom bonded to three hydrogen atoms and one hydrogen molecule, bearing a"
"undertaking the work, saying: ""It is all about the challenge and the possibility to astonish chemists about what can be possible."" Hexamethylbenzene Hexamethylbenzene, also known as mellitene, is a hydrocarbon with the molecular formula CH and the condensed structural formula C(CH). It is an aromatic compound and a derivative of benzene, where benzene's six hydrogen atoms have each been replaced by a methyl group. In 1929 Kathleen Lonsdale reported the crystal structure of hexamethylbenzene, demonstrating that the central ring is hexagonal and flat and thereby ending an ongoing debate about the physical parameters of the benzene system. This was a"
"Group 14 hydride Group 14 hydrides are chemical compounds composed of hydrogen atoms and carbon group atoms (the elements of group 14 are carbon, silicon, germanium, tin, and lead). The tetrahydride series has the chemical formula XH, with X representing any of the carbon family. Methane is commonly the result of the decomposition of organic matter and is a greenhouse gas. The other hydrides are generally unstable, poisonous metal hydrides. They take on a pyramidal structure, and as such are not polar molecules like the other p-block hydrides. Unlike other light hydrides such as ammonia, water and hydrogen fluoride, methane"
"[3+2] cycloaddition of trimethylenemethane. Trimethylenemethane Trimethylenemethane (often abbreviated TMM) is a chemical compound with formula . It is a neutral free molecule with two unsatisfied valence bonds, and is therefore a highly reactive free radical. Formally, it can be viewed as an isobutylene molecule with two hydrogen atoms removed from the terminal methyl groups. The electronic structure of trimethylenemethane was discussed in 1948. It is a neutral four-carbon molecule containing four pi molecular orbitals. When trapped in a solid matrix at about 90 K, the six hydrogen atoms of the molecule are equivalent. Thus, it can be described either as"
"photo-dissociate the methane molecule into a methyl radical and a hydrogen atom. When two methyl radicals recombine, the result is ethane: On Earth’s atmosphere, hydroxyl radicals convert ethane to methanol vapor with a half-life of around three months. It was once widely hypothesized that ethane produced in this fashion on Titan rained back onto the moon's surface, and over time had accumulated into hydrocarbon seas or oceans covering much of the moon's surface. Infrared telescopic observations cast significant doubt on this hypothesis, and the Huygens probe, which landed on Titan in 2005, failed to observe any surface liquids, although it"
"Hexamethylbenzene Hexamethylbenzene, also known as mellitene, is a hydrocarbon with the molecular formula CH and the condensed structural formula C(CH). It is an aromatic compound and a derivative of benzene, where benzene's six hydrogen atoms have each been replaced by a methyl group. In 1929 Kathleen Lonsdale reported the crystal structure of hexamethylbenzene, demonstrating that the central ring is hexagonal and flat and thereby ending an ongoing debate about the physical parameters of the benzene system. This was a historically significant result, both for the field of X-ray crystallography and for understanding aromaticity. The compound can be prepared by reacting"
"is reaction with hydroxyl radicals that are formed by reaction of singlet oxygen atoms with water vapor. Methane is also present in the stratosphere, where methane's concentration decreases with height. Methane in the Earth's atmosphere is a strong greenhouse gas with a global warming potential (GWP) 104 times greater than CO in a 20-year time frame; methane is not as persistent a gas as CO and tails off to about GWP of 28 for a 100-year time frame. This means that a methane emission will have 28 times the impact on temperature of a carbon dioxide emission of the same"
"Methine group In chemistry, methine is a trivalent functional group =CH−, derived formally from methane. It consists of a carbon atom bound by two single bonds and one double bond, where one of the single bonds is to a hydrogen. The group is also called methyne or methene; its IUPAC systematic name is methylylidene or methanylylidene This name is also used for each carbon-hydrogen subunit of an aromatic compound, although the latter do not have discrete single and double bonds. This group is sometimes called ""methylidyne"", however that name belongs properly to either the methylidyne group ≡CH (connected to the"
"which the halogen atom abstracts a hydrogen atom from a methane molecule, resulting in the formation of a hydrogen halide molecule and a methyl radical (CH•). The methyl radical then reacts with a molecule of the halogen to form a molecule of the halomethane, with a new halogen atom as byproduct. Similar reactions can occur on the halogenated product, leading to replacement of additional hydrogen atoms by halogen atoms with dihalomethane, trihalomethane, and ultimately, tetrahalomethane structures, depending upon reaction conditions and the halogen-to-methane ratio. Methane is used in industrial chemical processes and may be transported as a refrigerated liquid (liquefied"
"order of parts per trillion. Atmospheric methane Atmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth's atmosphere. The 100-year global warming potential of methane is 28. That is, over a 100-year period, it traps 28 times more heat per mass unit than carbon dioxide and 32 times the effect when accounting for aerosol interactions. Global methane concentrations had risen from 722 parts per billion (ppb) in pre-industrial times to 1800 ppb by 2011, an increase by a factor of 2.5 and the"
"simplest conjugated hydrocarbon that cannot be given a Kekulé structure. It can be described as the superposition of three states: It has a triplet ground state ('/), and is therefore a diradical in the stricter sense of the term. Calculations predict a planar molecule with three-fold rotational symmetry, with approximate bond lengths 1.40 Å (C–C) and 1.08 Å (C–H). The H–C–H angle in each methylene is about 121 degrees. Of the three singlet excited states, the first one, 1 (1.17 eV above ground), is a closed shell diradical with flat geometry and fully degenerate threefold (D) symmetry. The second one,"
"unstable, and gradually undergo radioactive decay to become another element. The hydrogen nucleus contain just one proton, Its isotope deuterium, or heavy hydrogen, contains a proton and a neutron. Helium contains two protons and two neutrons, and carbon, nitrogen and oxygen - six, seven and eight of each particle, respectively. However, a helium nucleus weighs less than the sum of the weights of the two hydrogen nuclei which combine to make it. The same is true for carbon, nitrogen and oxygen. For example, the carbon nucleus is slightly lighter than three helium nuclei, which can combine to make a carbon"
"is named after methane (), by analogy with the derivation of ammonium ion () from ammonia (). Methanium can be visualised as a carbenium ion with a molecule of hydrogen interacting with the empty orbital in a 3-center-2-electron bond. The bonding electron pair in the H molecule is shared between the two hydrogen and one carbon atoms making up the 3-center-2-electron bond. The two hydrogen atoms in the H molecule can continuously exchange positions with the three hydrogen atoms in the ion (a conformation change called pseudorotation, specifically the Berry mechanism). The methanium ion is therefore considered a fluxional molecule."
"to one hydrogen and the other three carbons. Tetrahedral molecular geometry In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos(−⅓) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane (CH) as well as its heavier analogues. Methane and other perfectly symmetrical tetrahedral molecules belong to point group T, but most tetrahedral molecules have lower symmetry. Tetrahedral molecules can be chiral. Aside from virtually all saturated organic compounds, most compounds of Si, Ge, and Sn"
"does not exhibit any anomalous effects attributed to hydrogen bonding, and so its properties conform well to the prevailing trend of heavier group 14 hydrides. This series has the chemical formula XH. Ethane is commonly found alongside methane in natural gas. The other hydrides are even less stable than the tetrahydrides. All straight-chain saturated group 14 hydrides follow the formula XH, the same formula for the alkanes. Many other group 14 hydrides are known. Carbon forms a huge variety of hydrocarbons (with propane and butane following methane and ethane among the alkanes, but also including alkenes, alkynes, cyclic and branched"
"by burning it as a fuel in a gas turbine or steam generator. Compared to other hydrocarbon fuels, methane produces less carbon dioxide for each unit of heat released. At about 891 kJ/mol, methane's heat of combustion is lower than any other hydrocarbon but the ratio of the heat of combustion (891 kJ/mol) to the molecular mass (16.0 g/mol, of which 12.0 g/mol is carbon) shows that methane, being the simplest hydrocarbon, produces more heat per mass unit (55.7 kJ/g) than other complex hydrocarbons. In many cities, methane is piped into homes for domestic heating and cooking. In this context"