Various Kinds of Chemical Bonds Explained by SKMClasses Bangalore
Let us make the list in reverse order of popularity. Some types of Bonds such as Electrovalent, or Covalent are known to all.
1 ) catenanes are the least known. A catenane is a mechanically-interlocked molecular architecture consisting of two or more interlocked macrocycles. The interlocked rings cannot be separated without breaking the covalent bonds of the macrocycles. Catenane is derived from the Latin catena meaning "chain".
They are conceptually related to other mechanically interlocked molecular architectures, such as rotaxanes, molecular knots or molecular Borromean rings.
Recently the terminology "mechanical bond" has been coined that describes the connection between the macrocycles of a catenane. can be used to make molecular switches. In 1994, a chemist named Fraser Stoddard decided to make a catenane with five interlocked macrocycles! Successfully making this molecule took 14 days, and the resulting mixture contained about 5% of the desired product
2 ) Spherical resonance in Boron Cages and other 3 D molecules
3 ) Banana Bond or Half Bond - Bent bonds are a special type of chemical bonding in which the ordinary hybridization state of two atoms making up a chemical bond are modified with increased or decreased s-orbital character in order to accommodate a particular molecular geometry. Bent bonds are found in strained organic compounds such as cyclopropane, oxirane and aziridine.
4 ) Quintuple Bond - A quintuple bond in chemistry is an unusual type of chemical bond, first reported in 2005 for a dichromium compound. Single bonds, double bonds, and triple bonds are commonplace in chemistry. Quadruple bonds are rarer but occur currently among the transition metals, especially for Cr, Mo, W, and Re, e.g. [Mo2Cl8]4− and [Re2Cl8]2−. In a quintuple bond, ten electrons participate in bonding between the two metal centers, allocated as
σ2π4δ4
σ2π4δ4
5 ) Quadruple bonds - Pair of Atoms with 4 bonds. chromium(II) acetate. Cr2(μ-O2CMe)4(H2O)2, was the first chemical compound containing a quadruple bond to be synthesized. It was described in 1844 by E. Peligot, although its distinctive bonding was not recognized for more than a century.Many other compounds with quadruple bonds between transition metal atoms have been described, often by Cotton and his coworkers. Isoelectronic with the dirhenium compound is the salt K4[Mo2Cl8] (potassium octachlorodimolybdate). An example of a ditungsten compound with a quadruple bond is di-tungsten tetra(hpp).
6 ) Sextuple Bond - A sextuple bond is a type of covalent bond involving 12 bonding electrons and in which the bond order is 6. The only known molecules with true sextuple bonds are the diatomic dimolybdenum (Mo2) and ditungsten (W2), which exist in the gaseous phase. There is strong evidence to believe that no two elements in the periodic table with atomic number below about 100 can form a bond with greater order than 6
7 ) Sandwich bonds - phthalocyaninato metal sextuple-decker complex. Also in some cases known as covalent bonding in actinide sandwich molecules.
8 ) Eta bonds - Also known as Hapticity - Hapticity is the coordination of a ligand to a metal center via an uninterrupted and contiguous series of atoms.
The hapticity of a ligand is described with the Greek letter η ('eta'). For example, η2 describes a ligand that coordinates through 2 contiguous atoms. In general the η-notation only applies when multiple atoms are coordinated (otherwise the κ-notation is used). In addition, if the ligand coordinates through multiple atoms that are not contiguous then this is considered denticity (not hapticity), and the κ-notation is used once again. Lastly, bridging ligands are described with the μ ('mu') notation.
Ferrocene - bis(η5-cyclopentadienyl)iron
Uranocene - bis(η8-1,3,5,7-cyclooctatetraene)uranium
W(CO)3(PPri3)2(η2-H2 ) - the first compound to be synthesized with a dihydrogen ligand ( also known as Dihydrogen Complexes )
IrCl(CO)[P(C6H5)3]2(η2-O2) - the dioxygen derivative which forms reversibly upon oxygenation of Vaska's complex.
The hapticity of a ligand is described with the Greek letter η ('eta'). For example, η2 describes a ligand that coordinates through 2 contiguous atoms. In general the η-notation only applies when multiple atoms are coordinated (otherwise the κ-notation is used). In addition, if the ligand coordinates through multiple atoms that are not contiguous then this is considered denticity (not hapticity), and the κ-notation is used once again. Lastly, bridging ligands are described with the μ ('mu') notation.
Ferrocene - bis(η5-cyclopentadienyl)iron
Uranocene - bis(η8-1,3,5,7-cyclooctatetraene)uranium
W(CO)3(PPri3)2(η2-H2 ) - the first compound to be synthesized with a dihydrogen ligand ( also known as Dihydrogen Complexes )
IrCl(CO)[P(C6H5)3]2(η2-O2) - the dioxygen derivative which forms reversibly upon oxygenation of Vaska's complex.
9 ) Ligands - Coordination complex or metal complex consists of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands. Many metal-containing compounds, especially those of transition metals, are coordination complexes. Coordination complexes were known – although not understood in any sense – since the beginning of chemistry, e.g. Prussian blue
and copper vitriol. The key breakthrough occurred when Alfred Werner proposed in 1893 that Co(III) bears six ligands in an octahedral geometry. His theory allows one to understand the difference between coordinated and ionic in a compound, for example chloride in the cobalt ammine chlorides and to explain many of the previously inexplicable isomers.
In 1914, Werner resolved the first coordination complex, called hexol, into optical isomers, overthrowing the theory that only carbon compounds could possess chirality. The ions or molecules surrounding the central atom are called ligands. Ligands are generally bound to the central atom by a coordinate covalent bond (donating electrons from a lone electron pair into an empty metal orbital), and are said to be coordinated to the atom. There are also organic ligands such as alkenes whose pi bonds can coordinate to empty metal orbitals. An example is ethene in the complex known as Zeise's salt, K+[PtCl3 (C2H4)]−.
1. They are used in photography, i.e., AgBr forms a soluble complex with sodium thiosulfate in photography.
2. K[Ag(CN)2] is used for electroplating of silver, and K[Au(CN)2] is used for gold plating.
3. Some ligands oxidise Co2+ to Co3+ ion.
4. Silver and gold are extracted by treating zinc with their cyanide complexes.
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and copper vitriol. The key breakthrough occurred when Alfred Werner proposed in 1893 that Co(III) bears six ligands in an octahedral geometry. His theory allows one to understand the difference between coordinated and ionic in a compound, for example chloride in the cobalt ammine chlorides and to explain many of the previously inexplicable isomers.
In 1914, Werner resolved the first coordination complex, called hexol, into optical isomers, overthrowing the theory that only carbon compounds could possess chirality. The ions or molecules surrounding the central atom are called ligands. Ligands are generally bound to the central atom by a coordinate covalent bond (donating electrons from a lone electron pair into an empty metal orbital), and are said to be coordinated to the atom. There are also organic ligands such as alkenes whose pi bonds can coordinate to empty metal orbitals. An example is ethene in the complex known as Zeise's salt, K+[PtCl3 (C2H4)]−.
1. They are used in photography, i.e., AgBr forms a soluble complex with sodium thiosulfate in photography.
2. K[Ag(CN)2] is used for electroplating of silver, and K[Au(CN)2] is used for gold plating.
3. Some ligands oxidise Co2+ to Co3+ ion.
4. Silver and gold are extracted by treating zinc with their cyanide complexes.
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10 ) ODD-ELECTRON BOND
THE ODD ELECTRON BOND IS ANOTHER TYPE OF BOND WHICH LITERALLY MEANS CONTAINING ODD NUMBER OF ELECTRONS.THERE ARE TWO TYPES OF ODD-ELECTRON BONDS THEY ARE-
THREE ELECTRON BOND
-It has been found that three electrons bond can never be formed if electro negativity difference exceeds 0.5.
-Three electrons bond must have larger bond length as compared to two electrons bond and must possess less bond energy.
-Three electrons bond molecules have tendency to dimerize.
-The three electrons bond is half of an electron pair bond.
-An odd bond is mostly equivalent to 1/2 normal electron pair bond
THE ODD ELECTRON BOND IS ANOTHER TYPE OF BOND WHICH LITERALLY MEANS CONTAINING ODD NUMBER OF ELECTRONS.THERE ARE TWO TYPES OF ODD-ELECTRON BONDS THEY ARE-
THREE ELECTRON BOND
-It has been found that three electrons bond can never be formed if electro negativity difference exceeds 0.5.
-Three electrons bond must have larger bond length as compared to two electrons bond and must possess less bond energy.
-Three electrons bond molecules have tendency to dimerize.
-The three electrons bond is half of an electron pair bond.
-An odd bond is mostly equivalent to 1/2 normal electron pair bond
11 ) Coordinate Bond or dative Bond - A covalent bond is formed by two atoms sharing a pair of electrons. The atoms are held together because the electron pair is attracted by both of the nuclei. In the formation of a simple covalent bond, each atom supplies one electron to the bond - but that does not have to be the case. A coordinate bond (also called a dative covalent bond) is a covalent bond (a shared pair of electrons) in which both electrons come from the same atom.
12 ) Back bonding - ( also known as Back donation ). Gives rise to partial triple bonds. A sigma bond arises from overlap of nonbonding sp-hybridized electron pair on carbon with a blend of d-, s-, and p-orbitals on the metal. A pair of π bonds arises from overlap of filled d-orbitals on the metal with a pair of π-antibonding orbitals projecting from the carbon of the CO. The latter kind of binding requires that the metal have d-electrons, and that the metal is in a relatively low oxidation state (<+2) which makes the back donation process favorable. As electrons from the metal fill the π-antibonding orbital of CO, they weaken the carbon-oxygen bond compared with free carbon monoxide, while the metal-carbon bond is strengthened. Because of the multiple bond character of the M-CO linkage, the distance between the metal and carbon is relatively short, often < 1.8 Â, about 0.2 Â shorter than a metal-alkyl bond. Several canonical forms can be drawn to describe the approximate metal carbonyl bonding modes.
13 ) VAN DER WAALS FORCES ( or molecular bonding ) - named after Dutch scientist Johannes Diderik van der Waals, is the sum of the attractive or repulsive forces between molecules (or between parts of the same molecule) other than those due to covalent bonds, or the electrostatic interaction of ions with one another, with neutral molecules, or with charged molecules. Most fibers, cloth, wood, very wide variety of materials ( such as polymers ) stands on this.
This is the most common interaction or bonding.
This is the most common interaction or bonding.
14 ) Disperson London Forces - The London dispersion force is the weakest intermolecular force. It is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.every atom and molecule has electrons and that these electrons are in constant motion. At any one instant in time, these electrons can be more towards one side of a molecule than another. When the electrons are concentrated more at one end of a molecule, that end becomes slightly negative. The other end, where the electrons are not as concentrated, becomes slightly positive. At this instant, this molecule is a temporary dipole. This dipole can encourage a nearby molecule to also become dipole because the negative side of the first molecule will cause the electrons to run away on the other molecule (since negative (-) detests negative (-)). These two adjacent dipoles created from the movement of electrons are attracted to each other. This very weak intermolecular force is called London dispersion force.
London dispersion force is the weak intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules.
London dispersion force is the weak intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules.
15 ) Hydrogen Bonding - In some cases the hydrogen atom is attached directly to one of the most electronegative elements, causing the hydrogen to acquire a significant amount of positive charge. Each of the elements to which the hydrogen is attached is not only significantly negative, but also has at least one "active" lone pair. Lone pairs at the 2-level have the electrons contained in a relatively small volume of space which therefore has a high density of negative charge. Lone pairs at higher levels are more diffuse and not so attractive to positive things. Hydrogen bonds have about a tenth of the strength of an average covalent bond, and are being constantly broken and reformed in liquid water. Life is due to hydrogen bond. ATCG is connected by hydrogen bonds.
Intramolecular Hydrogen bond is possible.
Intramolecular Hydrogen bond is possible.
16 ) Dipole - Dipole Bond - Dipole-Dipole interactions result when two polar molecules approach each other in space. When this occurs, the partially negative portion of one of the polar molecules is attracted to the partially positive portion of the second polar molecule. This type of interaction between molecules accounts for many physically and biologically significant phenomena such as the elevated boiling point of water. Hydrogen bond sometimes is referred as Dipole Dipole interaction.
17 ) Sigma bond - Particular kind of covalent bond in which electrons are shared between atoms is called a sigma bond. Here the overlap is headon, or axially.
18 ) Pi bond - Here the electron cloud overlap is sidewise. pi bonds (π bonds) are covalent chemical bonds where two lobes of one involved atomic orbital overlap two lobes of the other involved atomic orbital. Each of these atomic orbitals is zero at a shared nodal plane, passing through the two bonded nuclei. The same plane is also a nodal plane for the molecular orbital of the pi bond.
19 ) Delta Bond - delta bonds (δ bonds) are covalent chemical bonds, where four lobes of one involved atomic orbital overlap four lobes of the other involved atomic orbital. This overlap leads to the formation of a bonding molecular orbital with two nodal planes which contain the internuclear axis and go through both atoms.
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding. We have polar covalent bonds when atoms have difference in electronegativity.
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding. We have polar covalent bonds when atoms have difference in electronegativity.
20 ) Ionic bond - Ionic bonding is a type of chemical bond that involves the electrostatic attraction between oppositely charged ions. These ions represent atoms that have lost one or more electrons (known as cations) and atoms that have gained one or more electrons (known as an anions). In the simplest case, the cation is a metal atom and the anion is a nonmetal atom, but these ions can be of a more complex nature, e.g. molecular ions like NH4+ or SO42-
21 ) Scientists from Taiwan have made interlocking daisy-chain-like molecular structures that can switch from an expanded and contracted position based on the removal and addition of zinc, mimicking muscle behavior.
22 ) Supramolecules - A chemical bond between two negatively charged molecules of bisulfate, or HSO4. Previously a "supramolecule" with two negatively charged ions—was once regarded as impossible. An anion-anion dimerization of bisulfate goes against simple expectations of Coulomb's law. In these molecules the long-range repulsions between these anions are offset by short-range attractions. The dimers are connected by many weak non-covalent bonds. A negatively charged particle is an anion.
23 ) Physicists have observed a strange molecule called the butterfly Rydberg molecule - a weak pairing of highly excitable atoms that was first predicted back in 2002. Rydberg molecules are unique because they can have electrons that are between 100-1,000 times further away from the nucleus than normal.
Rydberg molecules form when an electron is kicked far from an atom's nucleus, making them super electronically excited. A team of researchers from Purdue University in Indiana predicted that a Rydberg molecule could attract and bind to another atom - something that was thought impossible according to our understanding of how atoms bind at the time. They called that hypothetical molecule combination the butterfly Rydberg molecule, because of the butterfly-like distribution of the orbiting electrons. The team was able to create them for this experiment by cooling Rubidium gas to a temperature of 100 nano-Kelvin - one ten-millionth of a degree above absolute zero - then exciting the atoms into a Rydberg state using lasers.
Rydberg molecules form when an electron is kicked far from an atom's nucleus, making them super electronically excited. A team of researchers from Purdue University in Indiana predicted that a Rydberg molecule could attract and bind to another atom - something that was thought impossible according to our understanding of how atoms bind at the time. They called that hypothetical molecule combination the butterfly Rydberg molecule, because of the butterfly-like distribution of the orbiting electrons. The team was able to create them for this experiment by cooling Rubidium gas to a temperature of 100 nano-Kelvin - one ten-millionth of a degree above absolute zero - then exciting the atoms into a Rydberg state using lasers.
24 ) Carbon seen bonding with 6 other Atoms
In certain conditions, carbon can be stretched beyond this limit, says Moritz Malischewski, a chemist at the Free University of Berlin who synthesised and studied the molecule, called hexamethylbenzene. Typically, this compound resembles a ship’s wheel, consisting of six carbon atoms arrayed in a hexagonal ring, with extra carbon-atom arms protruding from the ring’s outer edge. In an experiment in 1973, German chemists took away two of the compound’s electrons, and evidence suggested that the positively charged version then collapsed in on itself and formed a pyramid. In this arrangement, there are six electrons available to connect the top of the pyramid to the five carbons in the rest of the ring and the extra arm, Malischewski says.
It is an unusual, unstable arrangement that exists only at low temperatures inside extremely acidic liquids. So Malischewski spent six months tinkering with a potent acid to produce the compound and derive a few milligrams of crystals that could then be viewed using X-rays.
Quantum calculations and other experiments suggested a six-bond carbon atom was possible, but the crystal structure serves as photographic proof, says Dean Tantillo at the University of California, Davis. “It sheds light on the nature of bonding and the limits of our understanding of organic chemical structures,” he says.
In normal temperature and humidity, the molecule would break down immediately, so it is unlikely to have any practical applications, such as producing new types of carbon nanotubes.
But Malischewski says he was just intrigued by the question of whether the molecule could even exist. “It is all about the challenge and the possibility to astonish chemists about what can be possible,” he says.
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