Ionic bonds are formed between 2 or more than atoms by the transfer of one or more electrons betwixt atoms.
Organic Chemical science
Structure of Organic Compounds
Principles of Organic Chemistry, 2015
class between two or more atoms by the transfer of ane or more electrons between atoms. Electron transfer produces negative ions chosen
and positive ions called
These ions attract each other.
Let’due south examine the ionic bail in sodium chloride. A sodium atom, which has 11 protons and 11 electrons, has a single valence electron in its 3s subshell. A chlorine atom, which has 17 protons and 17 electrons, has seven valence electrons in its third shell, represented as 3s23p5. In forming an ionic bail, the sodium atom, which is electropositive, loses its valence electron to chlorine. The resulting sodium ion has the same electron configuration as neon (ls22s22p6) and has a +
1 charge, because in that location are 11 protons in the nucleus, merely only 10 electrons about the nucleus of the ion.
The chlorine atom, which has a high electronegativity, gains an electron and is converted into a chloride ion that has the aforementioned electron configuration as argon (ls22s22p63s23p6). The chloride ion has a −1 charge because there are 17 protons in the nucleus, but there are 18 electrons well-nigh the nucleus of the ion. The germination of sodium chloride from the sodium and chlorine atoms can exist shown by Lewis structures. Lewis structures represent but the valence electrons; electron pairs are shown as pairs of dots.
Note that by convention, the complete octet is shown for anions formed from electronegative elements. Notwithstanding, the filled outer shell of cations that results from loss of electrons by electropositive elements is not shown.
Metals are electropositive and tend to lose electrons, whereas nonmetals are electronegative and tend to gain electrons. A metal atom loses 1 or more electrons to form a cation with an octet. The same number of electrons are accustomed by the advisable number of atoms of a nonmetal to form an octet in the anion, producing an ionic compound. In general, ionic compounds outcome from combinations of metallic elements, located on the left side of the periodic table, with nonmetals, located on the upper correct side of the periodic table.
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Structure and Bonding in Organic Compounds
Organic Chemistry (Second Edition), 2018
are formed between two or more atoms past the transfer of ane or more electrons between atoms. Electron transfer produces negative ions called
and positive ions called
cations. Ionic substances exist every bit crystalline solids. When the solid dissolves, the ions dissociate and can diffuse freely in solution.
Sodium chloride is an case of an ionic solid. A sodium atom, which has 11 protons and 11 electrons, has a single valence electron in its 3s subshell. A chlorine atom, which has 17 protons and 17 electrons, has seven valence electrons in its third shell, represented every bit 3s23pfive. In forming an ionic bond, the sodium atom, which is electropositive, loses its valence electron to chlorine. The resulting sodium ion has the same electron configuration as neon (1sii
2s22p6). It has a +
1 charge, considering in that location are eleven protons in the nucleus, simply only ten electrons around the nucleus of the ion. The chlorine atom, which has a loftier electronegativity, gains an electron and is converted into a chloride ion that has the same electron configuration as argon (1stwo
3s23p6). The chloride ion has a −
one charge because at that place are 17 protons in the nucleus, just there are eighteen electrons around the nucleus of the ion.
In the crystal structure, each sodium ion is surrounded by six chloride ions and each chloride ion is surrounded by six sodium ions. Each ion has a consummate electron shell that corresponds to the nearest inert gas; neon for a sodium ion, argon for a chloride ion (Figure 1.4).
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Geochemistry | Soil, Major Inorganic Components☆
van der Jagt
Encyclopedia of Analytical Science (Tertiary Edition), 2019
Formation of ionic bond
tin can exist formed after two or more atoms loss or gain electrons to form an ion. Ionic bonds occur between metals, losing electrons, and nonmetals, gaining electrons. Ions with contrary charges volition attract one some other creating an ionic bail. Such bonds are stronger than hydrogen bonds, but like in strength to covalent bonds.
In an ionic bond, the atoms are bound by attraction of opposite ions, whereas in a covalent bail, atoms are bound past sharing electrons. In covalent bonding, the geometry effectually each atom is determined past valence beat out electron pair repulsion theory (VSEPR rules), whereas in ionic materials, the geometry follows maximum packing rules. Thus, a compound tin be classified as ionic or covalent based on the geometry of the atoms. It only occurs if the overall energy change for the reaction is favorable (the bonded atoms take a lower energy than the free ones). The larger the free energy alter the stronger the bail.
ionic bonding doesnot happen with real atoms. All bonds take a small amount of covalence. The larger the deviation in electro negativity the more ionic the bond. Impression of 2 ions (for example [Na]+
and [Cl]−) forming an ionic bond. Electron orbital generally does not overlap (i.due east., Molecular orbital is not formed), because each of the ions reached the lowest energy country, and the bond is based simply (ideally) on the electrostatic interactions between positive and negative ions. Many ionic solids are soluble in water, although not all. It depends on whether there are big enough attractions between the water molecules and the ions to overcome the attractions between the ions themselves. Positive ions are attracted to the ion pairs on h2o molecules and coordinate (dative covalent) bonds may form. Water molecules form hydrogen bonds with negative ions.
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Bonding Energy Models
Encyclopedia of Materials: Science and Technology, 2001
grade betwixt elements with very unlike electronegativities, resulting in transfer of electrons between the atoms. Transfer of the electrons is energetically unfavorable (the ionization energy is larger than the electron affinity free energy), only the energy of the resulting attraction between the ions is larger than the energy price to transfer electrons. There are many types of models for ionic bonding, with the simplest being a pair potential consisting of an attractive term (between charged particles) and a repulsive term (due to overlap of electron clouds). A common case is the Built-in–Meyer potential
is the number of electrons in the outer shell of ion
is a parameter related to the size of the ion, and ρ
is an empirical parameter describing the
of the electronic cloud.
Unlike the LJ model, which is relatively short-ranged, ionic pair potentials are extremely long-ranged, and interactions between all ions in the arrangement must exist considered. This would exist computationally expensive, as calculations would then scale as the number of particles squared. Still, approaches such as the Ewald sum and the more recent multipole approach have reduced the scaling to approximately linear with no pregnant loss of accuracy.
In that location have been several extensions to the Born–Meyer type of model, to include the effect of noncentrosymmetric charge distributions and polarized ions, which provide better accuracy at the price of additional computational try. In general, ionic models piece of work best for highly ionic systems such as NaCl. For systems with mixed ionic–covalent bonding, similar SiO2, it is necessary to add in angular terms (encounter Sect.
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Review of Bones Organic Chemistry
Fire Debris Analysis, 2008
is formed past the complete transfer of some electrons from one atom to some other. The atom losing one or more than electrons becomes a cation—a positively charged ion. The atom gaining one or more electron becomes an anion—a negatively charged ion. When the transfer of electrons occurs, an electrostatic allure between the two ions of opposite charge takes identify and an ionic bond is formed.
A salt such as sodium chloride (NaCl) is a good example of a molecule with ionic bonding (see
Figure 3-3). The diminutive number of the element sodium (Na) is 11, meaning that a sodium atom possesses eleven protons and eleven electrons. Its electronic configuration is 1s2
3sane. In this land, there is but one electron in the valence beat. The trend is for sodium to lose an electron so that the new resulting valence shell (ii) is in its most stable state (full octet). This loss of an electron results in the ionization of sodium, to course the positively charged ion Na+.
The other atom of the table salt is chlorine (Cl), which has the diminutive number 17, and the electronic configuration 1stwo
3pv. This configuration shows that the chlorine atom has seven electrons in its valence shell. Its tendency is to pick up an electron to form an octet, thus completing its third shell. In doing and so, chlorine becomes the negatively charged ion Cl–. Because of the propensity of sodium to lose an electron and of chlorine to proceeds an electron, the elements are well suited to bond with one another. This transfer of electrons results in the formation of the ionic bond holding Na+
together. Ionic bonding is very common in inorganic chemistry just is encountered much less oftentimes in organic chemical science.
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Properties of nanomaterials
Chemistry of Nanomaterials, 2020
ionic bonds, the complete transfer of i or more electrons occurs between the donor and acceptor elements. There are few factors that crusade the formation of ionic bonds; 1 of them is the large differences in electronegativity of atoms, which attract other atoms for the transfer of their electrons. This chemical interaction of electrons creates a strong bonding between the atoms equally compared to other types of bonds. For instance, in the example of Sodium chloride (NaCl) or Potassium chloride (KCl), an electron is transferred between the donor (Na) and acceptor (Cl). Equally a effect, an Na
salt is formed every bit shown in
Fig. 4.2. A large amount of energy is required to transfer the electrons from the sodium to the chlorine atom. Later on the transfer of electrons, sodium loses 3
s electrons and becomes sodium ions (Na+), while the chlorine chemical element gains an electron and becomes chlorine ions (Cl−)
In nanotechnology, pure electrostatic interactions of electrons betwixt ionized atoms such as salts (NaCl) are of less involvement. As compared to salts, poly ions likewise as molecular ions are of peachy interest in this field. Macromolecules accept a large corporeality of parallel functional groups, so when these macromolecules are ionized then polyionic macromolecules are
formed. When polyionic macromolecules interact with modest oppositely charged ions, stable multiple thin layers are formed every bit a result. Electrostatic bonds, surface charges, and electrostatic repulsion are necessary for the operation of nanoparticles, micelles, and macromolecules in the liquid phase. Moreover, by controlling the surface charges we can create and stabilize nanoheterogeneous systems
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Bimolecular reactions in solutions Influence of medium
Chemical Kinetics: Fundamentals and New Developments, 2003
Reactions of ions
Compounds with the
(salts) that form in the solid country the ion crystalline lattice dissociate to ions. Beingness dissolved, acids and bases undergo consummate or partial dissociation where a noticeable chemic interaction of ions with solvents occurs. Each ion in the solvent, eastward.k., in h2o, is surrounded by the dense solvate vanquish of polar molecules. This shell appears due to the ion-dipole interaction. Solvation is manifested, first, in that the dissolution of a salt in H
twoO is accompanied past a decrease in the book and, 2d, liberation of a great amount of estrus. This is seen from the ΔH
values where the ion from the gas phase is transferred to an aqueous solution (ΔH
The potent interaction of the ion with the solvent is reflected all physicochemical properties of solutions of electrolytes. The classical electrostatic theory considers the
i-th ion equally a sphere with the radius
with the charge
and the solvent as a medium with the dielectric abiding ε = εexp(−50
In this simplified approach, the electrostatic components of the
Chiliad, H, and
functions are the following (eastward
is the charge of an electron):
Since many ions are present in a solution and they interact, this reflects both the ion distribution in the solution and their thermodynamic characteristics.
The reaction between two ions A and B is preceded past their encounter in a solution. If the reaction is not limited by see acts, then the experimentally observed rate constant
is the equilibrium constant of ion pair formation. It depends on the backdrop of both ions (charge, sizes) and medium (ε, ion
in two solvents with εo(G
o) and ε(One thousand
AB) and taking into account the effect of the ion strength of the solution co-ordinate to the Debye-Hückel theory, for kexp we obtain the expression
Bjerrum obtained the following expression:
is the distance betwixt atoms at their tight contact.
Two important sequences follow from (6.55). Start, the charge per unit constant of the ion reaction depends on the ionic strength of the solution and in dilute solution where
≪ i, Δlnk
1/two, which is confirmed by a large experimental cloth. In the case of the reaction of likely charged ions, the slope of Δlnk/Δ(I
ane/ii) is positive (the ion atmosphere facilitates the reaction); in the case of the reaction between unlike ions, this slope is negative, and the higher the production of charges zAzB, the higher the absolute value of the tangent slope. Deviations due to specific features of reaction mechanisms are oftentimes observed. Second, kexp depends on e in such a way that Δlnk
∼ Δ(ε−1). In this case, the higher the product |zAzB|, the greater the slope; for like charges the slope is negative, and for the unlike ions, the gradient is positive.
It is reasonable to consider the problem near the equilibrium concentration of ion pairs in a solution from the indicate of view of irresolute the thermodynamic functions ΔG, ΔSouthward, and ΔH. Since dispersion and electrostatic forces deed between ions, and the latter depend on the polarity of the medium and concentrations of other ions expressed through the ion strength, the equilibrium abiding of ion association can be presented in the form
Correspondingly, for the components of enthalpy we obtain
For the activation free energy, which is determined from experimental data
RT(dlnk/dlnT), nosotros take the expression [see
equation (half dozen.xviii)]
For the entropy contributions to ion association nosotros obtain (S
Co-ordinate to this, the pre-exponential factor
When the A ion reacts with the B molecule, the equilibrium clan constant has the form
The considered above electrostatic models of ion interaction are, undoubtedly, simplified. Each ion is surrounded past the solvate shell, whose character and sizes are adamant by the ion, its charge and radius, and sizes of solvent molecules and such their parameters as the dipole moment of their polar groups, structure and sizes of the molecule. The solvent, its solvating ability, and the influence on the ion interaction are non reduced to the medium with the dielectric constant e simply. Similarly, the interaction of ions is not restricted by the formation of but the ion atmosphere: ion pairs, triples, and associates of several ions announced in the solution. Ion pairs, which tin be separated by the solvate shell or be in contact to form contact pairs, also differ in structure. As a whole, the situation is more complex and diverse than its description by the classical theory of interaction of spherical charges in the liquid medium of dielectrics. The solvating power of the solvent is determined only in role past its dielectric constant. For aprotic solvents, the ability of their heteroatoms to be donors of a free pair of electrons for cations is very significant. The donating ability of the solvent is characterized past its donor number DN, which for the solvent is equal to the enthalpy of its interaction with SbCl5
in a solution of i, 2-dichloroethane
In protic solvents, the ability of the solvent to class hydrogen bonds is of import in ion solvation. In mixed solvents an ion forms a set of solvates with various compositions.
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Optical Properties of Fluoride Transparent Ceramics
Photonic and Electronic Properties of Fluoride Materials, 2016
Which Applications for Fluoride Transparent Ceramics?
Because of the highly
character, fluorides are remarkable materials for optical applications from IR to UV domain of wavelengths. As early as 1887, Otto Shott, Ernst Abbe, and Carl and Roderich Zeiss have investigated the possibility to use natural single crystals of calcium fluoride for optical lenses, and the Carl Zeiss company proposed CaF
lenses for microscope objectives in 1937. Nevertheless, the impurities in naturally occurring CaFii
limited their optical applications, and synthetic single crystal growth methods were adult to produce larger and more pure unmarried crystals. Since 1979, synthetically grown single crystal CaFii
has been used in some high-performance optical devices (camera objectives, telescopes, microscopes) due to its very low dispersion in the visible and IR wavelength ranges. Thus, lenses made from fluorite exhibit less chromatic aberration than those made of ordinary drinking glass and are commercially available in high-end optics such as those offered by the Takashi Inc. Single crystals oftentimes require months to grow and very high temperature. Their product is costly and the substitution of unmarried crystal by ceramic tin can reduce drastically the toll of the devices. This could only be achieved if the transparent ceramics are produced using a low-temperature procedure from powder and not single crystal. Contempo works seem to indicate that it is possible. Considering fluorides have wider optical transparency (190
μm for SrF2
and CaF2, for instance) than most oxide materials, they are materials of selection for windows in the UV or IR regions. Melt growth methods used to produce single crystals may not provide the scalability necessary to accomplish large piece to put windows in shape easily on the contrary of the processes used to elaborate ceramics from powders. Versus glasses for which synthesis processes allow the same advantages (scalability, facility to put in shape, toll), ceramics present the reward of best mechanical and thermomechanical properties. Another field of interest for the fluoride is scintillators. For example, since the 1980s, BaF2, Ce:BaF2, Eu:Ce:BaF2, or Ce:CaF2
as well as CeF3
are investigated to be used as fast and efficient scintillators for detection of X-rays, gamma rays, and loftier-energy particles. Today, Eu:CaF2
single crystals are commercially available for charged particle and soft gamma ray detection. The possibility to produce fluoride transparent ceramics opens thus the way for the manufacturing of complex devices associating pieces with different doping rates, for case, or/and big pieces with an interesting manufacturing cost. The last corking field of application for the fluoride transparent ceramics is the laser application, which merits to exist adult.
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Atomic Structure and Chemical Bonding
Fundamental Aliphatic Chemistry, 1965
Electrovalency—The Ionic Bond
In the formation of the
the octet is accomplished by the atoms gaining or losing electrons. Typical electrovalency is most commonly institute in compounds derived from elements situated in
the groups adjacent to the inert gases. Thus a sodium atom (ones
i) may lose the electron occupying the iiis
orbital, giving a sodium ion. The chlorine cantlet accepts the electron into the half-filled 3p
orbital to give a chloride ion. Both ions now have the electron configuration of the nearest inert gas (neon and argon respectively).
A crystal of sodium chloride is a symmetrical close-packed system of sodium and chloride ions held together by electrostatic forces. It is important to emphasize that there is no specific link between these oppositely charged ions and there is no entity which may be regarded equally being a sodium chloride molecule. The concrete properties characteristic of compounds formed by electrovalent bonding are crystalline form, high melting signal, h2o solubility and the ability of the fused common salt to acquit electricity. In organic compounds the electrovalent bond manifests itself in the sodium salts of carboxylic acids (R·CO2
Na⊕) and in the salts formed from an acid and an organic base of operations (east.g. methylamine hydrochloride CHiii·
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Plastics properties for packaging materials
Packaging Technology, 2012
Ionomers are unusual in that they have ionic as well as covalent bonds in the polymer chains. They are fabricated by reacting metal salts (commonly Na+
) with acidic copolymers such equally EAA or ethylene methacrylic acid (EMAA). The
human action like crosslinks between the polymer chains, resulting in tough, puncture resistant materials with excellent heat-sealing characteristics over a wide temperature range, and the ability to seal through contamination. Bonding to aluminium foil and paperboard is excellent. Ionomers also accept very skilful resistance to oily products, making them useful as oestrus-sealing layers for candy meats. They are as well used in rigid grade for closures. There is a large range of options from which to choose, the chief suppliers in the packaging field being DuPont, under the Surlyn® brand and Exxon Mobil under the Iotek™ make.
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Which Statement is True About Ionic Compounds