Triple bond Three pairs of electrons

Bonded atoms can share more than one electron pair. A double bond occurs when bonded atoms share two electron pairs in a triple bond, three pairs of electrons are shared. In ethylene (Q2H4) and acetylene (QHJ, the carbon atoms are linked by a double bond and triple bond, respectively. Using two parallel lines to represent a double bond and three for a triple bond, we write the structures of these molecules as... 

Note In VSEPR theory the term bond pair is used for a single bond, a double bond, or a triple bond, even though a single bond consists of one pair of electrons, a double bond two pairs of electrons, and a triple bond three pairs of electrons. To avoid any confusion between the number of electron pairs actually involved in the bonding to a central atom, and the number of atoms bonded to that central atom, we shall occasionally use the term ligand" to indicate an atom or a group of atoms attached to the central atom. 

In addition, carbon atoms can form strong single, double, or triple bonds with other carbon atoms. In a single carbon-carbon bond, one pair of electrons is shared between two carbon atoms. In a double bond, two pairs of electrons are shared between two atoms. In a triple bond, three pairs of electrons are shared between two atoms. 

Up to now, we have looked at covalent bonding in molecules or polyatomic ions that have only single bonds. However, in some molecular compounds, atoms share two or three pairs of electrons to complete their octets. A double bond occurs when two pairs of electrons are shared in a triple bond, three pairs of electrons are shared. Atoms of carbon, oxygen, nitrogen, and sulfur are most likely to form multiple bonds. Atoms of hydrogen and the halogens do not form double or triple bonds. 

Every group of electrons shared between two atoms constitutes a covalent bond. When one pair of electrons is involved, the bond is called a single bond. When two pairs of electrons unite two atoms, the bond is called a double bond. Three pairs of electrons shared between two atoms constitute a triple bond. Examples of these types of bonds arc given below ... 

In a triple covalent bond, three pairs of electrons are shared between the bonded atoms. It is represented by a triple-dash sign = ). 

Triple bonds are formed by the sharing of three pairs of electrons to form a a and two n bonds. Spatially these three bonds behave as a single bond. Consequently acetylene (ethyne) C2H2 has the linear configuration often represented as H—C=C—H. 

Two atoms may share up to three pairs of electrons in single bonds (two shared electrons, one line), double bonds (four shared electrons, two lines), or triple bonds (six shared electrons, three lines). 

In the structural formula for O2, the sharing of two pairs of electrons is represented by two parallel dashes—a double bond. Sometimes three pairs of electrons are shared, producing a triple bond, which is indicated by three parallel dashes. 

Triple bond A bond in which three pairs of electrons are shared. 

Atoms can share more than a single pair of electrons. When atoms share two pairs of electrons, they re said to form a double bond, and when they share three pairs of electrons, they re said to form a triple bond. Figure 5-5 shows examples of double and triple bonds using electron dot structures and line structures. 

Triple bond The sharing of three pairs of electrons by two atoms. 

The atoms of some elements (such as C, N, and O) are able to share more than one pair of electrons between them, to form single, double, or triple bonds—depending on whether one, two, or three pairs of electrons are shared. In general, the bonding energy increases and the internuclear distance decreases as the number of bonds between a pair of atoms increases. 

The triple covalent bond with two atoms bonded by three pairs of electrons is known for instance in the case of nitrogen (N N-.) or of acetylene (H C C H). 

In a similar way, a triple bond involves sharing of three pairs of electrons and is indicated by three lines e.g. between the carbon atoms in ethyne, H-C=C-H. 

Triple bond A covalent bond between two atoms, made up of three pairs of electrons. 

Rule 3 If two or three pairs of electrons form a multiple bond between two atoms, the first bond is a sigma bond formed by a hybrid orbital. The second bond is a pi bond, consisting of two lobes above and below the sigma bond, formed by two unhybridized p orbitals (see the structure of ethylene in Figure 2-17). The third bond of a triple bond is another pi bond, perpendicular to the first pi bond (shown in Figure 2-18). 

In Section 2-4, we studied the electronic structure of a triple bond. Let s review this structure, using acetylene as the example. The Lewis structure of acetylene shows three pairs of electrons in the region between the carbon nuclei ... 

Acetylene (C2H2) has a triple bond. Its Lewis structure shows three pairs of electrons between the carbon atoms to give them octets. The following examples show organic compounds with triple bonds. A triple dash (=) symbolizes a triple bond. 

When atoms share three pairs of electrons, they form a triple bond. Diatomic nitrogen contains a triple bond, as you can see in Figure 3.19. Try the following problems to practise representing covalent bonding using Lewis structures. Watch for multiple bonding ... 

The two nitrogen atoms share six electrons or three pairs of electrons. This means that there are three bonds between the two nitrogen atoms, N = N. This is called a triple bond. 

Triple Bond Triple Point A covalent bond that involves the sharing of three pairs of electrons. A specific point in temperature and pressure at which solid, liquid, and gas exist at the same time. 

In this case, three electron pairs are shared, and each nitrogen atom has an octet of electrons. There is one lone pair of electrons on each nitrogen atom. Three pairs of electrons shared between the same two atoms constitute a triple bond. If two pairs of electrons are shared, a double bond results. Consider the carbon dioxide molecule ... 

So far, we have discussed bonds in which one pair of electrons is shared. This type of bond is called a single bond. As we will see in more detail later, atoms sometimes share two pairs of electrons, forming a double bond, or share three pairs of electrons, forming a triple bond. The bond energies for these multiple bonds are also given in Table 13.6. 

This planar structure is the one expected for three pairs of electrons around a central atom, which means that a double bond should be counted as one effective pair in using the VSEPR model. This makes sense because the two pairs of electrons involved in the double bond are not independent pairs. Both of the electron pairs must be in the space between the nuclei of the two atoms to form the double bond. In other words, the double bond acts as one center of electron density to repel the other pairs of electrons. The same holds true for triple bonds. This leads us to another general rule For the VSEPR model multiple bonds count as one effective electron pair. 

Triple bond a bond in which three pairs of electrons are shared by two atoms. (13.8)... 

Carbon, oxygen, and nitrogen atoms often form double bonds by sharing two pairs of electrons. Carbon and nitrogen atoms may even share three pairs of electrons to form a triple bond. Think about the molecule N2. With five valence electrons, each N atom needs three more electrons for a stable octet. Each N atom contributes three electrons to form three bonding pairs. The two N atoms form a triple bond by sharing these three pairs of electrons, or a total of six electrons. Because the two N atoms share the electrons equally, the triple bond is a nonpolar covalent bond. 

A triple covalent bond is formed when three pairs of electrons are shared between two atoms. Nitrogen (N2) shares three electron pairs, producing a triple bond. One nitrogen atom needs three additional electrons to attain a noble-gas configuration. Figure 9-5b shows the triple bond formed between two nitrogen atoms. 

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