Hybridization of atomic orbitals in carbon. Hybridization of electronic orbitals and geometry of molecules

Sp2 hybridization

As a result of the hybridization of one s-orbital and two p-orbitals, three hybrid sp 2 -orbitals are formed, arranged in the same plane at the bottom 120 one to one. For example, this is the configuration of the BF3 molecule:

Fig.4 sp 2 -hybridization

sp 3 -hybridization is typical for semi-coal. As a result of hybridization of one s-orbital and three

p-orbitals utvoryuyutsya chotiri hybrid sp 3 -orbitals, straightened to the tops of the tetrahedron with a cut between the orbitals 109.5 pro. Hybridization is manifested in the total equality of bonds between the carbon atom and the smaller atoms in the hemispheres, for example, CH 4 , CCl 4 , C(CH 3) 4 and in.

Fig.5 sp 3 -hybridization

As all hybrid orbitals are bound by the same atoms, the bonds do not intersect one by one. In other valleys, small winds traverse along the standard valence slopes. For example, in the water molecule H 2 O, the oxygen is sp 3 -hybrid, located in the center of an irregular tetrahedron, at the top of which "marvel" two atoms of water and two non-substant pairs of electrons (Fig. 2). The shape of the molecule is curvy, as if marveling at the centers of the atoms. Valence cut HOH becomes 105 pro, which should be close to the theoretical value of 109 pro.

Fig.6 sp 3 hybridization of oxygen atoms and nitrogen in molecules a) H 2 O and b) NCl 3 .

Yakby did not experience hybridization (“reversal” of O-H bonds), the valence cut of HOH reached 90°, so that atoms and water would be added to two mutually perpendicular p-orbitals. In this way, our world looked bi, maybe, zovsіm іnakshe.

The theory of hybridization explains the geometry of the ammonia molecule. As a result of hybridization of 2s and three 2p orbitals, four sp 3 hybrid orbitals are converted to nitrogen. The change of the molecule is the twisting of tetrahedrons, in which three hybrid orbitals take part in the illumination of the chemical bond, and the fourth with a pair of electrons does not. Kuti between the links N-H is not equal 90 about the pyramid, but not equal 109.5 about the same tetrahedron.

Fig.7 sp 3 - hybridization in ammonia molecules

When ammonia interacts with the water ion, after the donor-acceptor interaction, the ammonium ion is dissolved, the configuration of which is a tetrahedron.

Hybridization also explains the presence of the core between O-H bonds in the core of the water molecule. As a result of hybridization of 2s and three 2p orbitals, some hybrid sp 3 orbitals are established, of which only two take part in the established chemical bond, which leads to the creation of a kuta, which forms a tetrahedron.

small 8 sp 3 hybridization in water molecules

In hybridization, not only s-i p-, but also d-i f-orbitals can be included.

With sp 3 d 2 -hybridization, 6 equal globules are established. She will be afraid in such folds like 4-, 4-. For which molecule can have the configuration of an octahedron:

Rice. nine d 2 sp 3 -hybridization in ions 4-

The findings about hybridization allow one to understand such peculiarities of the existence of molecules that cannot be explained in any other way.

Hybridization of atomic orbitals (AT) to produce a direct bond with other atoms until the electron cloud is used. Through war, the areas of overlap of hybrid orbitals show up more, lower pure orbitals and the number of connections increases.

Hybridization of orbitals- virіvnyuvannya energy and forms of orbitals.

The essence of the process of hybridization of atomic orbitals is that an electron near the nucleus of a linked atom is characterized not by a single atomic orbital, but by a combination of atomic orbitals with the same quantum number. Such a combination is called a hybrid orbital. Hybridization takes on only those that are close to the energy of atomic orbitals, occupied by electrons.

Hybrid orbitals may have an asymmetric shape, twisted at the back of the atom, which makes it easy.

Type of hybrid atomic orbital, created by mixing s-і p- orbitals.

Electronic glooms are mutually released and spread out in the space as far as possible in the distance, one type of one, which shows the minimum energy of the electronic air supply. At the same axis, the sp 3 hybrid orbitals appear straight to the vertices of the tetrahedron (regular triangular pyramid), and the cuts between these orbitals are tetrahedral, equal 109 28".

The type of hybridization determines the geometry of the ion molecule.

Types of hybridization

Type of hybridization	warehousemen	geometric shape	Kut mizh zv'azkami	Apply
	1 s- orbital ta 1 p- orbital	linear
	1 s- orbital ta 2 p- orbitals	trikutna
	1 s- orbital ta 3 p- orbitals	tetrahedral
sp 3 d	1 s- orbital, 3 p- orbitals ta 1 d- orbital	trigonal bipyramidal
sp 3 d 2	1 s- orbital, 3 p- orbitals i 2 d- orbitals	octahedral

The tops of the electronic orbitals can be twisted one by one. Crossing the electronic haze along the line that passes through the centers of the atoms is called sigma (ϭ )-viscous .

Covalent link, which is settled by a path of lateral twisting R-orbitals of sucid carbonic atoms, called pi (π )-viscous .

Because the area of ​​the area of ​​overlap of the orbitals at π - the link is less, the same link is less mіtsna, lower link.

sp3 hybridization

sp 3 -hybridization - hybridization, in which to take the fate of atomic orbitals of one s- and three p-Electroniv (Fig. 1).

Rice. one. osvita sp 3-hybrid orbitals

Chotiri sp 3-hybrid orbitals are symmetrically oriented at the expanse under the apex 109°28" (Fig. 2).

Model of the atom sp 3-hybrid orbitals

Spacious configuration of the molecule, the central atom of which is the solution sp 3-hybrid orbitals - tetrahedron

Tetrahedral spacious configuration of the molecule, the central atom of which sp 3-hybrid orbitals

hybridization atom orbital carbon

Apply z'ednan, for some it is characteristic sp 3-hybridization: NH 3 , POCl 3 , SO 2 F 2 , SOBr 2 , NH 4+ , ​​H 3 O + . So, sp 3-hybridization occurs in all boundary carbohydrates (alkanes, cycloalkanes) and other organic halfs: CH 4 , C 5 H 12 , C 6 H 14 , C 8 H 18 and in. The general formula of alkanes is: C n H 2n+2. The general formula of cycloalkanes is: CnH2n. In the boundary carbohydrates, all chemical links are single, so it is only possible between hybrid orbitals at- perekryvannya.

Utvoryuvat khіmіchny zv'yazok, tobto. it is possible to create a single electron pair with a “foreign” electron from another atom only by unpaired electrons. Unpaired electronics for an hour of recording electronic formulas are rebuyed at the clitin-orbital.

atomic orbital- tse funktsіya, yak describ schіlnіst elektronії gloom near the skin point to the expanse near the nucleus of the atom. Electronic gloom is the whole area of ​​space, in which you can know the electron in a high world.

To improve the electronic life of the carbon atom, the valency of the carbon element is corroded by the manifestations of the destruction of the carbon atom. In a normal (unawakened) steel, a carbon atom can have two mismatches 2 R 2 electrons. In an awakened state (with drenched energy) one out of 2 s 2-electron can go to Vilna R-orbital. So in atoms of carbon there are some unpaired electrons:

Guess what in the electronic formula of the atom (for example, for carbon 6 C - 1 s 2 2s 2 2p 2) large numbers before the letters - 1, 2 - indicate the number of the energy level. Literi sі R indicate the shape of the electronic gloom (orbital), and the right-handed numbers above the letters indicate the number of electrons on the given orbital. mustache s-orbitals are spherical

On another energy level, krim 2 s-orbitals є three 2 R-orbitals. Qi 2 R-orbitals make an ellipsoidal shape, I look like dumbbells, and are oriented in space under the hood 90 ° one to one. 2 R-Orbitals mean 2 R X , 2R y i 2 R z Vіdpovіdno to the axes, uzdovzh yakіh qі orbіtalі roztashovanі.

Shape and orientation of p-electron orbitals

When the chemical bonds are established, the electronic orbitals take on the same shape. So, at the boundary in carbohydrates, one fluctuates s-orbital i three R-orbitals of the carbon atom with the adoption of some of the same (hybrid) sp 3-orbitals:

Tse - sp 3-hybridization.

hybridization- virіvnyuvannya (zmіshuvannya) atomic orbitals ( sі R) with the adoption of new atomic orbitals, titles hybrid orbitals.

Chotiri sp 3 - hybrid orbitals of the carbon atom

Hybrid orbitals may have an asymmetric shape, twisted at the back of the atom, which makes it easy. Electronic glooms are mutually visible and spread out in the space as far as possible one view of one. With which axis chotirioh sp 3-hybrid orbitals they are straightened to the vertices of the tetrahedron (regular triangular pyramid).

Vidpovidno, cut between these orbitals - tetrahedral, equal 109°28".

The tops of the electronic orbitals can overlap with the orbitals of other atoms. If the electron particles intersect along the line, which is the center of the atoms, then such a covalent bond is called sigma () - zv'azkom. For example, in a molecule of ethane H 2 H 6, a chemical bond is established between two carbon atoms overlapping two hybrid orbitals. Tse zv'azok. In addition, the leather is made of carbon atoms with its trioma. sp 3-orbitals intersect with s-orbitals of three atoms in water, satisfying three links.

Schematic diagram of the overlap of electron clouds in the etane molecule

For the carbon atom, three valence states are possible with a different type of hybridization. Crimea sp 3-hybridization sp 2 - i sp-Hybridization.

sp 2 -hybridization- zmіshuvannya odnієї s- and two R-orbitals. As a result, three hybrids are established sp 2 -orbitals. qi sp 2-orbital roztasovanі in one plane (with axes X, at) and straightening up to the tops of the tricot with a fold between the orbitals 120 °. unhybridized R-orbital is perpendicular to the area of ​​three hybrids sp 2-orbitals (oriented to the axis z). Upper half R-orbitals are above the plane, the lower half is under the plane.

Type sp 2-hybridization of the charcoal buvae at the floor with a lower link: Z=Z, Z=O, Z=N. Moreover, more than one of the links between two atoms (for example, C \u003d C) can be a link. (The other linking orbitals of the atom are directed in the opposite directions.) R-orbitals along the sides of the line, which is behind the nuclei of atoms.

Orbitals (three sp 2 i one p) carbon atom in sp 2 -hybridization

Covalent link, which is settled by a path of lateral twisting R-orbitals of sucid carbonic atoms, called pi()-star.

Illumination-zvyazku

Through less overlap of the orbitals, the link is less mіtsna, the lower one is the link.

sp-hybridization- tse zmіshuvannya (virіvnyuvannya behind the form of that energy) alone s- that alone R-orbitals with two hybrids sp-orbitals. sp- Orbital roztashovanі on one line (nіd kutom 180 °) and straightened at the protilene side in the direction of the nucleus of the atom charcoal. Two R-orbitals become unhybridized. The stench of placement is mutually perpendicular to the straight lines-links. To the little one sp-orbitals show vzdovzh axis y, and unhybridized two R-orbital- vzdovzh axes Xі z.

Atomic orbitals (two sp and two r) coalesce in the sp-hybridization station

Loss of carbon-coarse tie of the SS is folded into a tie, which is to blame for the twisting sp- hybrid orbitals, the other two - links.

Electronic Budova atom vugletsyu

The coal that enters the warehouse of organic sprouts shows permanent valency. On the remaining energy level of the atom, there are 4 electrons in the carbon, two of them occupy the 2s-orbital, which has a spherical shape, and two electrons occupy the 2p-orbitals, which have a dumbbell-like shape. When excited, one electron from the 2s orbitals can go to one of the vacant 2p orbitals. This transition will require some energy vitrates (403 kJ/mol). As a result of the excitation, the carbon atom can have 4 unpaired electrons and its electronic configuration is expressed by the formula 2s1 2p3.

An atom of coal in an excited state of the building establishes 4 covalent bonds per shell of 4 wet unpaired electrons and 4 electrons of other atoms. So, in times of carbohydrate methane (CH4), a carbon atom makes 4 bonds with s-electrons of an atom in water. In which case, 1 bond of the s-s type (between the s-electron of the carbon atom and the s-electron of the water atom) and 3 p-s-link (between 3 p-electrons of the carbon atom and 3 s-electrons of 3 atoms) water). Sounds of vyplyvay vysnovok about nerіvnotsіnіnіst chotirioh covalent zv'yazykіv, scho utvoryuyuyutsya carbon atom. However, a practical explanation of chemistry is that all 4 bonds in the methane molecule are absolutely equal, and the methane molecule is tetrahedral with 109 ° valence bonds, which could not be with the unevenness of the bonds. Even though the orbitals of the p-electron are oriented in space along the mutually perpendicular axes x, y, z, and the orbital of the s-electron has a spherical shape, it would be enough to directly illuminate the connection with this electron. The theory of hybridization could explain this mistake. L. Polling, having said that there are no bonds between molecules that are isolated from each other. When the bonds are established, the orbitals of all valence electrons are twisted. Vіdomo kіlka types of hybridization of electronic orbitals. It is believed that 4 electrons enter into the molecules of methane and other alkanes before hybridization.

Hybridization of the orbitals of the carbon atom

Hybridization of orbitals is a change in the form and energy of active electrons when a covalent bond is established, which leads to a more effective distortion of the orbitals and an increase in the minerality of the bonds. The hybridization of orbitals is always known, as in the light of the links take the fate of electrons, which lie down to different types of orbitals. 1. sp 3 -hybridization (first valence camp of coal). With sp3 hybridization, 3 p-orbitals and one s-orbital of the excited atom in carbon are mutually modified in such a way that the orbitals appear to be absolutely the same in terms of energy and are symmetrically arranged in space. The whole transformation can be written like this:

s+px+py+pz=4sp3

During hybridization, the total number of orbitals does not change, but only the energy of that form changes. It is shown that the sp3-hybridization of the orbitals predicts a volume, one of the spades being significantly larger than the other. Chotiri hybrid orbitals wind up in the center to the vertices of a regular tetrahedron under the corners 109.50. Links made by hybrid electrons (for example, links s-sp 3) are larger, lower links, which are formed by non-hybridized p-electrons (for example, links-s-p). the sp3-orbital hybrid oscillators provide a larger area of ​​electronic orbital overlapping, the p-orbital is unhybridized lower. Molecules that have sp3 in them - hybridization may have a tetrahedral pattern. Before them, cream to methane, there are homologues to methane, inorganic molecules like ammonia. The little ones show a hybridized orbital and tetrahedral methane molecule. Chemical bonds that are attributed to methane between carbon atoms and water can be seen up to type 2 y-links (sp3-s-links). Vzagali, be it sigma-links, are characterized by the fact that the electron gap of two atoms connected to each other intersects along the line, which is behind the center (nucleus) of the atoms. At the link, it is necessary to give the maximum possible degree of distortion of atomic orbitals; 2. sp2 -hybridization (another valence mill). Blame the result of overlapping one 2s and two 2p orbitals. Sp2-hybridized orbitals, which have settled, are spread out in the same plane under the tip of 1200 one to one, and the p-orbital is unhybridized perpendicularly to it. The total number of orbitals does not change - they are chotiri.

s + px + py + pz = 3sp2 + pz

Mill sp2 -hybridization zustrіchaєtsya in the molecules of alkenіv, in carbonyl and carboxyl groups, tobto. at the z'єdnan, scho mayut at his warehouse podvіyny zv'yazok. So, in a molecule of ethylene hybridized electrons, a carbon atom has 3 y-links (two sp 2 -s links between a carbon atom and water atoms and one sp 2 -sp 2 link between carbon atoms). The p-electron of one carbon atom, which is left unhybridized, makes p-links with the non-hybridized p-electron of another carbon atom. A characteristic feature of the p-link is those that overlap the orbitals of the electrons in the same position with the line, which connects two atoms. The recurve of the orbitals is higher and lower at the link, which hurts the atoms of the coal. In such a rank, a subway link is a combination of u-ta r-zv'yazkiv. The first two small images show that in the ethylene molecule the valences between the atoms that make up the ethylene molecule become 1200 (appears to be oriented with the expanse of three sp2 - hybrid orbitals). On the third and fourth little ones, the adoption of the r-zvyazku is shown. ethylene (illumination of u-sv'yazkіv) ethylene (illumination of n-z'yazkіv) less mіtsna, nizh y-zvyazok and easier to develop in chemical reactions. 3. sp-hybridization (the third valence mill of coal). In the sp-hybridization station, a carbon atom can be two sp-hybrid orbitals, lined up at the edge of 1800 one to one and two non-hybridized p-orbitals are lined up at two mutually perpendicular planes. sp-hybridization in alkynes and nitriles, tobto. for z'єdnan, scho mayut at your warehouse a lost link.

s + px + py + pz = 2sp + py + pz

So, in a molecule of acetylene, the valence between atoms becomes 1800. The hybridized electrons of the carbon atom establish 2 y-bonds (one sp-s bond between the carbon atom and the water atom and another sp-sp bond between the carbon atoms. Two unhybridized p-electrons of one carbon atom form two p- bonds with non-hybridized p-electrons of another atom in the corner. the language is a combination of one y-link The presence of a molecule of acetylene is less than two r-links, making it safe for speech to enter into a reaction with the opening of a third link.

Visnovok: sp3-hybridization is typical for semi-cooly. As a result of the hybridization of one s-orbital and three p-orbitals, two hybrid sp3-orbitals are formed, straightened to the vertices of the tetrahedron with a cut between the 109° orbitals.

hybridization- Virіvnyuvannya (zmіshuvannya) atomic orbitals ( sі R) with the adoption of new atomic orbitals, titles hybrid orbitals.

atomic orbital- this function, as a way to describe the scope of electronic gloom at the skin point to the expanse of the nucleus of an atom. Electronic haze - the whole area of ​​​​expansion, in a high degree of omnivornistyu can be knowledge of an electron

Sp-hybridization

Vіdbuvaєtsya at zmіshuvanni one s- and one p-orbitals. Two equal sp-atomic orbitals are adjusted, lined up 180 degrees along the edge and in the direction of the different sides of the nucleus of the central atom. Two non-hybrid p-orbitals, which are left out, roam at mutually perpendicular planes and take part in the established π-bonds, otherwise they are engaged in incompatible pairs of electrons.

Sp2 hybridization

Sp2 hybridization

Vіdbuvaєtsya at zmіshuvanni one s- and two p-orbitals. Three hybrid orbitals are established with axes, ruffled in one plane and straightened to the tops of the tricutnik under a 120 degree cut. The non-hybrid p-atomic orbital is perpendicular to the i-plane, as a rule, taking part in the established π-bonds

In the table, it is shown the application of the most extensive types of hybridization and the geometric structure of the molecules in the admissible, that all hybrid orbitals take part in the established chemical links (per day non-matching electronic betting)

Type of hybridization	Number of hybrid orbitals	Geometry	Structure	Apply
		Liniya		BeF 2 , CO 2 , NO 2 +
sp 2		Trikutna		BF 3, NO 3 -, CO 3 2-
sp 3		tetrahedral		CH 4, ClO 4 -, SO 4 2-, NH 4 +
dsp 2		flat-square		Ni(CO) 4 , 2-
sp 3 d		Hexahedral
sp 3 d 2 , d 2 sp 3		Octahedral		SF 6 , Fe(CN) 6 3- , CoF 6 3-

4. Electrovalent, covalent, donor-acceptor, aqueous link. Electronic Budova σ and π zv'azku. The main characteristics of a covalent bond: bond energy, dozhina, valence cut, polarity, polarization.

If between two atoms or two groups of atoms in a space, there is an electrostatic interaction, which leads to a strong heaviness of that chemical bond, then such a bond is called electrovalent heteropolar.

Covalent bond- chem_chny zv'yazok, utavleniyam perekrittam bet valence electronic hmar. Electronic gloom, scho secure zv'yazok, called a hot electronic pair.

Donor-acceptor link -tse chemical bond between two atoms or a group of atoms, which is created for the account of an unshared pair of electrons of one atom (donor) and a free equal of another atom (acceptor). Tsej zv'yazok vіdrіznyaєtsya vіd covalent zv'yazku podzhennyam elektronnym zv'yazku.

Water call -the same kind of chemical interaction of atoms in a molecule is due to the fact that the exact fate of the new atom takes water, even though it is bound by a covalent bond with other atoms

σ link is the first and greater mіtsny link, which is established when the electronic haze is crossed in a straight line, which is behind the center of the atoms.

σ bonds are primary covalent bonds of carbon atoms with water atoms. Molecules of boundary carbons are less likely to sv'yazku.

π bonds

The electronics π and σ bond lose their belonging to the single atom.

Features of σ and π bond: 1) the wrapping of carbon atoms in molecules is possible in the case, as the stink of the σ bond is viscous;

Dovzhina zv'yazku- tse stand between the centers of linking atoms.

valentine cut- tse kut between two svyazkami, scho maє zagalny atom.

Energy zv'yazku- energy, which is seen during the illumination of chem. zv'azku that її mіtsnіst, which is characterized

Polarity The connection is zoomed in by an uneven rump of the electron thickening due to the influences in the electronegativity of the atoms. For this sign, covalent bonds are subdivided into non-polar ones and polar ones. Polarization The sound is heard from the displaced electrons. The sound is heard under the influx of the positive electric field, including the other particles that react. The polarizability depends on the electronics' jitteriness. The polarity and polarization of covalent bonds determine the reactivity of the molecules according to the ratio to polar reagents.

5. Ionny link (electrovalent) - even though there is a chemical bond, which is established between atoms with a great difference in electronegativity, with such a bright electron pair it is important to pass to the atom with a greater electronegativity. The covalent bond is blamed for the success of the electronic bet for the help of the exchange mechanism, if the skin is made of atoms, which interact, it delivers one electron at a time. A donor-acceptor bond (coordination bond) is a chemical bond between two atoms or a group of atoms, which is formed for the balance of an unshared pair of electrons of one atom (donor) and a free orbital of another atom (acceptor). water, connected with small, ale electronegative atoms, for example: O, N, F. On the other hand, it is important that the electronegative atoms are smaller than the non-negotiable electronic bet. If electrons hit an atom of water of one molecule (acceptor) in interaction with an unshared electron pair on N atoms, O or F of another molecule (donor), forming bonds, is similar to a polar covalent. When a covalent bond is established in the molecules of organic half-shells, an electron pair populates molecular bonding orbitals, which may lower energy. Fallow in the form of MO - σ-MO or π-MO - bonds, which are settled, are brought to σ- or p-type. σ-linkage - covalent linkage, solutions in case of skewed s-, p- and hybrid AT uzdovzh osі, scho behind the nucleus of linking atoms (that is, with axial skewed AT). π-link is a covalent link, which is to blame for the side-curve of non-hybrid r-AT. Such an overlapping pose is straight, which hits the nuclei of atoms.
π-bonds bind between atoms, already connected by σ-bonds (with which the subfolding and lossy covalent bonds are established). The π-link is weaker than the σ-link, through a smaller outward overlap of the p-AT. The difference between σ- and π-molecular orbitals determines the characteristic features of σ- and π-links. 1.σ-Links are equal to π-links. The reason for this is more efficient axial overlap of AT in the presence of σ-MO and the presence of σ-electrons between nuclei. 2. According to σ-bonds, intramolecular wrapping of atoms is possible, because the form of σ-MO allows such a wrapping without breaking the link (with animated picture below)). Wrapping on the subvertical (σ + π) link is impossible without opening the π-link! 3. Electrons on π-MO, perebuvayushchie pose mezh'nuclear expanse, mayut more fluctuations in the line with σ-electrons. Therefore, the polarizability of the π-bond is significantly higher than that of the σ-bond.

Characteristics of the dominance of a covalent bond - straightness, saturation, polarity, polarization - signify the chemical and physical dominance of the spoluk.

The straightening of the link is zoomed in by the molecular bud speech and the geometric shape of their molecules. Kuti between two people is called valence with links.

Nasichuvanist - zdatnist of atoms to establish the exchange of covalent bonds. The number of sounds, approved by the atom, is surrounded by the number of yogo zvnіshnіh atomic orbitals.

The polarity of the link is zoomed in by the uneven distribution of the electron density due to the influences in the electronegativity of the atoms. For this sign, covalent bonds are subdivided into non-polar and polar ones (non-polar - diatomic molecule is composed of the same atoms (H 2, Cl 2, N 2) that electronic chromium of the skin atom is divided symmetrically to atoms; polar - diatomic molecule is composed of atoms chemical elements, and the scatter electron haze is displaced at the side of one of the atoms, which by itself satisfies the asymmetry of the distribution of the electric charge in the molecule, generating the dipole moment of the molecule).

The polarizability of the link is observed in the displaced electron link under the influx of a positive electric field, including other particles that react. The polarizability depends on the electronics' jitteriness. The polarity and polarization of covalent bonds determine the reactivity of the molecules according to the ratio to polar reagents.

6.Nomenclatureє a system of rules that allow you to give an unambiguous name to a skin individual. For medicine, knowledge of the sacramental rules of the nomenclature can be especially important; At the present time, it's hot IUPAC systematic nomenclature(IUPAC - International Union of Theoretical and Applied Chemistry) *.

However, dosі zberіgayutsya and widely zastosovuyutsya (especially in medicine) trivial(Zvichaynі) and semi-trivial names, vicorists before, as it became common for everyday speech. In these names, natural dzherela and methods of imitation can appear, especially commemorating the power of that sphere of stosuvannya. For example, lactose (milk tsukor) is seen from milk (Lat. lactum- milk), palmitic acid - from palm oil, pyruvic acid is taken away during the pyrolysis of tartaric acid, licorice relish is called glycerin (from Greek. glykys- Solodky).

Trivial names are especially common for natural causes - amino acids, carbohydrates, alkaloids, steroids. The use of some trivial and similar names, which have taken root, is allowed by the IUPAC rules. Before such names one can see, for example, “glycerin” and the names of richly aromatic carbohydrates and similar ones.

Rational nomenclature of boundary carbohydrates

On the face of the obvious, the names are grounded on the life of molecules. The names of the folding structures are composed of the names of the blocks and radicals connected with the main most important node of the molecule for the whole nomenclature of the alkane, they are seen as similar to methane at any atom and water substitution by water radicals. The selection of methane carbon, more than the 1st day of the month, can be named according to the nomenclature of alkenes as similar to ethylene and alkine-acetylene.

7. Homology of organic sproutsor the law of homology- I believe in the fact that speeches have the same chemical function and the same life, that one kind of one on their atomic warehouse is less than nCH 2, they are shown by the stars and in their own other chemistry. characters, and the power of their physical powers grows and changes correctly in the world of increased retail at the warehouse, which is characterized by the number n of groups CH 2. Such chemistries. similar spoluky make so sound. the homologous series, the atomic warehouse of all members of which can be shown by the common formula in the fallow in the warehouse of the first member of the series and the number of atoms in carbon; organic speech, one name is nibito alkanes only.

Izomeri- z'єdnannya may be the same warehouse of life and power.

8.Nucleofіflax and electrotrophіflax reagenti. The reagents that take the fate of the substitution are subdivided into nucleophiles and electrophiles. Nucleophilic reagents, or nucleophiles, put their pair of electrons on the establishment of a new bond and remove the group (X) from the RX molecule, then, with a pair of electrons, that established the old bond, for example:

(de R is an organic radical).

Before nucleophiles, one can see negatively charged ions (Hal - , OH - , CN - , NO 2 - , OR - , RS - , NH 2 - , RCOO - that іn), neutral molecules that can form a free pair of electrons (for example, H 2 O , NH3, R 3 N, R 2 S, R 3 P, ROH, RCOOH), and organometallic. z'ednannya R-Me with a polarized bond C-Me +, so that it can be donors of carbanions R-. Reactions due to the participation of nucleophiles (nucleophilic substitution) are characteristic of the head rank For aliphatic diseases, for example, hydrolysis (OH - , H 2 O), alcoholism (RO - , ROH), acidolysis (RCOO - , RCOOH), amino acid (NH - 2 , NH 3 , RNH 2 ta in), cyanuvannya (CN -) and so on.

Electrochemical reagents, or electrotrophils, when a new bond is established, serve as electron pair acceptors and remove the group from a seemingly positively charged particle. Positively charged ions (for example, H + , NO 2 +), neutral molecules with an electron deficit, for example SO 3 and strongly polarized molecules (CH 3 COO - Br + ta іn) are seen to electrophiles, and the polarization is especially effectively reached by the complex with Lewis coefficients (Hal + - Hal - A, R + - Cl - A, RCO + - Cl - A, de A \u003d A1C1 3, SbCl 5, BF 3 and in). Prior to the reactions involving electrotrophies (electrotrophil substitution), the most important reactions of aromatic hydrocarbons (for example, nitration, halogenation, sulfation, Friedel-Crafts reaction) are seen:

(E+=Hal+, NO+2, RCO+, R+ta in)

In singing systems, the reactions for the participation of nucleophiles are in the aromatic series, and the reactions for the participation of electrophiles are in the aliphatic series (most often in a number of organometallic compounds).

53. interaction of oxo compounds with organometallic compounds (ketone and aldehyde plus organometallic)

Reactions are widely used for the possession of alcohols.

1) sp- or q 2 - hybridization is characteristic if you take the fate of the illuminator 1sі 1 p- electron.

Rice. 16. Scheme sp- hybridization

Molecule can be of linear type AB 2 .

2) sp2- or q 3 - hybridization. Hybrid glooms grow under the top of 1200 in one flat (Fig. 17).

When the hybrid gloom is settled, I take the fate of one sі

2p electron.

Rice. 17. Scheme sp2- hybridization

For example, a molecule BCl 3

The molecule takes the form of a flat tricot.

3) sp3- q 4 - hybridization zdijsnyuetsya for one s ta trioch p- electronic mess. Khmars with this type of hybridization grow under the cut of 109 0 28 ¢ (Fig. 18). 4 hybrid gloomy directions from the center of a regular tetrahedron to its vertices. The butt of such a molecule can be CH4, CCl4.

Rice. 18. Scheme sp 3- Hybridization

Krіm looked at the possibility of other types of hybridization of valence orbitals and types of space configuration of molecules that suggest them. Combination of one s- three p - that one d- orbitals to produce up to sp3d- hybridization. Tse vіdpovіdaє orientation p'yati sp3d- hybrid orbitals to the tops of the trigonal bipyramid sp 3 d 2- hybridization six sp 3 d 2 hybrid orbitals are oriented to the vertices of the octahedron. Orientation of seven orbitals to the tops of the pentagonal sp 3 d 3(otherwise sp3d2f) – hybridization of the valence orbitals of the central atom of the molecule.

Also, the directness of chemical bonds determines the expanse of the configuration of molecules.

There are many types of vindictive molecules that can be seen.

Molecules type AA chi AB. Molecules can be seen to this type, which are made up of two identical or different atoms, between which one is single ( s- sigma) svyazok, the rest can be settled for the rahunok of the mutual modality of two s- electroniv, one per skin atom ( s¢ - s¢), two p- electronic ( p¢ - p¢) or two electrons of mixed type ( s¢ - p¢) (Fig. 19). Such links vindicate between the atoms of the elements that can be one s- or p- electron: water, elementi groupi IA(spuds of metal) that group VIIA(Halogeni). Molecules of this type can form a linear form, for example,
H 2 , F 2 , Cl 2 , Br 2 , J 2 , Zi 2 , Na 2 , K 2 , HCl that in.

Rice. 19. Perekrittya s-і p- orbitals

with illumination s- zv'azku

Molecules of type AB2, AB3. The stench settles for the rahunok between the two p- electrons of the atom ATі s- electrons in two atoms A. Two unpaired p- electrons are characteristic of atoms of elements VI A groupie, tobto. for sour and yoga analogues (chalcogens).

Electronic haze p- elektronіv roztashovuetsya clearly one to one pіd kutom 900 along the coordinate axes xі y.

Rice. 20. Recurve of the orbitals of the water molecule

For example, a molecule H2O(fig. 20) overlap hmar s- electronics with gloom p- electronics are seen in the area marked by shading, and to that chemical sounds can be straightened at a 90º cut. Such molecules are called kutovimi. However, according to experimental data, molecules with lower values ​​of the valence cut are significantly more frequently observed. For example, a water molecule has a valence cut of 104.5º. one of the reasons for this phenomenon, based on the theory of valence bonds, is the presence of non-bonding electron pairs at the central atom. The occurrence of valence coils in this way is due to the mutual effects of the binding and non-binding electron pairs of the central atom. Under the Tsomu, the enemy, the Khmara Zv'yazuvalo Eleknroni Pim (locked the cousins ​​of atomas), more than the mossy, the khmara is unhealthy ethnic -ethnic beta, the huts are manifested in pairs. scho not zv'yazuє i zv'yazuє, i, nareshti, less vіdshtovhuvannya mizh with spoluchnymi electron pairs. It can be seen on the application of the molecules of methane, ammonia and water. The central atoms of these molecules establish chemical bonds for electron beams s p 3 - hybrid orbitals fall into chotiri electrons

Tse vyznaє utvorennya chotiriokh zv'yazkіv C-H that decomposition of atoms into water molecules of methane CH 4 at the vertices of the tetrahedron (Fig. 21)

Rice. 21. Recurve orbitals of the methane molecule

At the nitrogen atom on chotiri sp3- hybrid orbitals fall five electrons:

Also, one pair of electrons appears to be unconnected and takes one sp3- orbitals straight to the vertices of the tetrahedron. As a result of the non-binding electron pairing, the valence coot of the ammonia molecule H3N appear less than tetrahedral and become < HNH = 107,3º .

It is now clear that, looking at the molecules of water, valence may be less than that. I sour at the atom 4 sp 3– hybrid orbitals have six electrons, that is. two sp3- hybrid orbitals occupy unconnected electronic bets. Vіdshtovhuvalnі dії dvoh

non-binding couples appear more importantly. Therefore, the valence cut is more strongly opposed to the tetrahedral one in water molecules. H2O warehouse < HOH = 104º,5¢ . With the increase in the number of unconnected electrons of the central atom, the space configuration of molecules changes (Table 7). So, if a molecule has the shape of a regular tetrahedron with a carbon atom in the center, then at the same time the molecules H3N You can imagine that one of the vertices of the tetrahedron is occupied by an electron pair, which does not link, and the molecule has the shape of a trigonal pyramid. Molecule H2O two vertices of the tetrahedron are occupied by electron pairs, and the molecule itself can be shaped. V- I will draw a form.

tetrahedron trigonal kutova

type AB 4 pyramid type AB 2 (A 2)

CH 4 type AB 3 NH 3 H 2 O

The polarity of the call. The link between the atoms of different electrons is more or less polar. It depends on the difference between the differences and the electronegativity of the atoms. For example, the chloride molecule has water HCl zv'yazuvalna electronic khmara is shifted at a large negative chlorine atom. After all, the charge of the nucleus is not compensated for, but in the atoms of chlorine, the electron gap becomes superfluous against the charge of the nucleus.

Table 7

Spacious configuration of molecules ABn

Type of hybridization	The number of electron pairs of an atom A	Molecule type	Space configuration	Apply
Ringing	non-binding
sp			AB 2	linear	BeCl 2 (g) CO 2
sp 2			AB 3 AB 2	trikutna kutova	BCl 3 CO 3
sp 3			AB 4	tetrahedral	CCl 4 , BH ,NH
			AB 3 AB 2	trigonal-permidal apex	H 3 N, H 3 P H 2 O
sp 3 d 1			AB 5	trigonal bipyramidal	PF 5 , SbCl 5

In other words, the atom HCl positive polarizations, and the chlorine atom is negative; Atomic water has a positive charge, and atomic chlorine has a negative charge. Tsey charge d- called effective, yoga can be installed experimentally. Zgidno with obvious tributes, ef-

effective charge per atom and water molecule HCl warehouse dH = +0.2, and on chlorine atoms dCl = -0.2 the absolute charge of the electron.

In this rank, behind the stage of zsuvu (polarization) of a successful electronic haze, links can be non-polar, polar or ionic. Non-polar and ionic links - extreme deviations of the polar link.

Non-polar and polar molecules. In non-polar molecules, the centers of gravity of positive and negative charges are shifted. Polar molecules are dipoles, that is. systems that are composed of two equal by magnitude and opposite by charge sign ( +qі -q) l one kind of one, which is called a long dipole. The polarity of the molecule, as well as the polarity of the bond, is estimated by the value of її dipole moment. m

m = l q,

de l- Dovzhina dipole, q- The amount of electrical charge.

l may be of the order of the diameter of an atom, that is. 10 -8 cm, and the electron charge 4,8∙10 -10 ate Art. one, to that m expressed in order of magnitude 10 -18 ate Art. one ∙ div. Qiu value is called Debye's unity and is approved by the letter D. The system has one CI m vimiryuєtsya in pendant - meters (K?m); 1 D = 0.33∙10 -29 K∙m.

The value of the dipole moment of covalent molecules lies at the boundaries 0-4D, ionic 4-11D.

The dipole moment of a molecule is the vector sum of the dipole moments of all bonds and non-couplings of electron pairs in a molecule. The result of folding is to lie in the structure of the molecule. For example, a molecule CO2, for rahunok sp hybridization of the orbitals of the atom with carbon, may be symmetrical to the linear bud.

(m = 1.84 D or 0,61∙10 -29 K∙M)

The presence of the dipole moment indicates the high-symmetry structure of the molecule, the presence of the dipole moment indicates the non-symmetry of the molecule.

Polarization of sound. To characterize the reactivity of the molecules, it is important to know how the current distribution of the electron gap, and the lightness, which will change. Serve the rest of the world polarization- її zdatnіst stavat polar (or more polar) after the infusion of the electric field on it.

As a result of polarization, a new bond can be formed with the transition of the electron pair, which links, up to one atom in the negative and positive ions. The asymmetric opening of the connection with the adopted different ions is called heterolytic.

homolytic heterolytic

opening opening

(dissociation) (ionization)

Heterolytic expansion breaks down into a collapsed bond when a molecule decomposes into atoms and radicals. In the rest of the fall, the linking electron pair collapses and the process is called homolytic. Vidpovidno before the said, there is a difference between the process of dissociation and the process of ionization; in times HCl the first one is afraid of thermal decomposition into atoms, the other - in case of decomposition into ions at the point of difference.

Under the influx of a positive electric field, the molecule is polarized, tobto. it has a redistributed charge and the molecule acquires a new value of the dipole moment. Under which non-polar molecules can transform into polar ones, and polar ones become even more polar. Still hanging, under the influx of the outer electric field, the molecules induce a dipole, we will induce the ranks of induction, if only for the influx of the outer electric field.