Single bonds orbital overlap

For a covalent bond to form, two atoms must be located so that an orbital of one overlaps an orbital of the other each orbital must contain a single electron. When this happens, the two atomic orbitals merge to form a single bond orbital which is occupied by both electrons. The two electrons that occupy a bond orbital must have opposite spins, that is, must be paired. Each electron has available to it the entire bond orbital, and thus may be considered to belong to both atomic nuclei. 

Bonds C-C a-bonds from overlap of methyl C sp with aldehyde C sp hybrid orbital [C p"-C p ] C=0 a-bond from overlap of aldehyde sp hybrid orbital with methyl C sp orbital C=0 n-bond from side-by-side overlap of C 2p and O 2p atomic orbitals C-H single bonds from overlap of HI s AOs and Csp" hybrid orbitals (methyl C atom) and H1 s AO and Csp hybrid orbital... 

Orbital Overlap in Single and Multiple Bonds Orbital Overlap and Molecular Rotation... 

Experimental evidence on the relationship between structure and reactivity in Norrish type II photochemistry of spirobenzoyladamantanes in the solid state has been produced. Geometric factors clearly determine partitioning between cleavage, cychzation, and hydrogen transfer reactions of the 1,4-biradical intermediate Cleavage becomes predominant when the singly occupied orbitals overlap poorly with one another but well with the central CC bond, which, as earlier sections indicate, has been presumed for years based on ketone structure. 

The C—C single bond in vmylacetylene is a a bond generated by overlap of an sp hybridized orbital on one carbon with an sp hybndized orbital on the other Vmylacetylene has three u bonds and three tt bonds... 

What is the maximum energy structure Does it correspond to a structure that prevents 7t-type orbital overlap What is the barrier to rotation about die C2-C3 single bond ... 

In the MO-CI language, the correct dissociation of a single bond requires addition of a second doubly excited determinant to the wave function. The VB-CF wave function, on the other hand, dissociates smoothly to the correct limit, the VB orbitals simply reverting to their pure atomic shapes, and the overlap disappearing. 

Carbon-carbon single bonds in alkanes are formed by a overlap of carbon sjy hybrid orbitals. Rotation is possible around a bonds because of their cylindrical... 

The diene must adopt what is called an s-cis conformation, meaning "cis-like" about the single bond, to undergo a Diels-Alder reaction. Only in the s-cis conformation are carbons 1 and 4 of the diene close enough to react through a cyclic transition state. In the alternative s-trans conformation, the ends of the diene partner are too far apart to overlap with the dienophile p orbitals. 

The valence atomic orbitals which are available to form the orbitals of a CC single bond, directed along the x axis, are the 2s and 2px atomic orbitals on each carbon atom. Their admixture—in proportions which depend on the number of neighbors at each carbon and on the subsequent hybridization—creates two (s, p ) hybrids on each atom. One of these hybrids points away from the other atom and can be used for bonding to additional atoms. The pair of hybrids which point at each other overlap and interact in the conventional fashion [we symbolize the non-interacting orbitals by an interruption of the bond axis (Fig. 1)]. The two bond orbitals which are formed in this manner both have [Pg.3]

A carbon-carbon double bond is stronger than one carbon-carbon single bond but weaker than the sum of two single bonds (Section 2.15). A carbon-carbon triple bond is weaker than the sum of three carbon-carbon single bonds. Recall that a single C—C bond is a o-bond, but the additional bonds in a multiple bond are TT-bonds. One reason for the difference in strength is that the side-by-side overlap of p-orbitals that results in a rr-bond is not as great as the end-to-end overlap that results in a o-bond. 

STRATEGY Use the VSEPR model to identify the shape of the molecule and then assign the hybridization consistent with that shape. All single bonds are cr-bonds and multiple i bonds are composed of a cr-bond and one or more TT-bonds. Because the C atom is attached to three atoms, we anticipate that its hybridization scheme is sp1 and that one unhybridized p-orbital remains. Finally, we form cr- and Tr-bonds by allowing the 1 orbitals to overlap. 

The carhon-carbon double bond in alkenes is more reactive than carbon-carbon single bonds and gives alkenes their characteristic properties. As we saw in Section 3.4, a double bond consists of a a-bond and a 7r-bond. Each carbon atom in a double bond is sp2 hybridized and uses the three hybrid orbitals to form three cr-bonds. The unhvbridized p-orbitals on each carbon atom overlap each other and form a Tr-bond. As we saw in Section 3.7, the carbon-carbon 7r-bond is relatively weak because the overlap responsible for the formation of the 7r-bond is less extensive than that responsible for the formation of the a-bond and the enhanced electron density does not lie directly between the two nuclei. A consequence of this weakness is the reaction most characteristic of alkenes, the replacement of the 77-bond by two new a-bonds, which is discussed in Section 18.6. 

The alternation of double and single bonds means that each C atom has an unhybridized /7-orbital that can overlap with the /7-orbital on either side. This arrangement allows electrons to be delocalized along the entire chain like a onedimensional version of graphite. 

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