Hybridization in carbon

This would be hybridization of one 3s and three 3p orbitals as opposed to 2s,2p hybridization in carbon. 

TABLE I. I Geometry and Hybridization in Carbon and Other Second Row Elements... 

The answer is D. This question also tests your basic knowledge of hybridization in carbon compounds. A triple bond means three bonds. Since there are three bonds, six electrons are involved in the bond. 

Depending on the degrees of carbon bond hybridization in carbon materials (i.e., sp, sp hybridization), various fabrication techniques have been developed to prepare different carbon nanostructures. These techniques are introduced individually for each category of carbon nanostructures. 

Figure 1-18 Hybridization in carbon to create four sp hybrids. The resulting bonding gives CH4 and other carbon compounds tetrahedral stmctures. The sp hybrids contain small back lobes of sign opposite that of the front iobes. In analogy to Rgure 1 -16B, the energy diagram of -hybridized carbon contains four singly occupied, equal-energy sp levels, in addition to the filled Is orbital.

FIGURE 2 20 Bonding in acetylene based on sp hybridization of carbon The carbon-carbon triple bond is viewed as consisting of one cr bond and two tt bonds... 

Section 2 20 Carbon is sp hybridized in ethylene and the double bond has a ct com ponent and a rr component The sp hybridization state is derived by mix mg the 2s and two of the three 2p orbitals Three equivalent sp orbitals result and their axes are coplanar Overlap of an sp orbital of one car bon with an sp orbital of another produces a ct bond between them Each carbon still has one unhybridized p orbital available for bonding and side by side overlap of the p orbitals of adjacent carbons gives a rr bond between them... 

FIGURE 17 2 Both (a) ethylene and (b) formal dehyde have the same num ber of electrons and carbon IS sp hybridized in both In formaldehyde one of the carbons is replaced by an sp hybridized oxygen Like the carbon-carbon double bond of ethylene the carbon-oxygen double bond of formaldehyde is com posed of a (T component and a TT component... 

FIGURE 19 1 Carbon -W and both oxygens are sp hybridized in formic acid The TT component of the C=0 group and the p or bital of the OH oxygen over lap to form an extended it system that includes carbon and both oxygens... 

The carbon that bears the functional group is 5/r -hybridized in alcohols and alkyl halides. Figure 4.1 illustrates bonding in methanol. The bond angles at carbon are approximately tetrahedral, as is the C—O—H angle. A similar- orbital hybridization model applies to alkyl halides, with the halogen connected to 5/r -hybridized carbon by a a bond. Carbon-halogen bond distances in alkyl halides increase in the order C—F (140 pm) < C—Cl (179 pm) < C—Br (197 pm) < C—I (216 pm). 

At 146 pm the C-2—C-3 distance in 1,3-butadiene is relatively short for a caibon-caibon single bond. This is most reasonably seen as a hybridization effect. In ethane both carbons are 5/r -hybridized and are separated by a distance of 153 pm. The carbon-carbon single bond in propene unites sp - and 5/r -hybridized carbons and is shorter than that of ethane. Both C-2 and C-3 are 5/r -hybridized in 1,3-butadiene, and a decrease in bond distance between them reflects the tendency of carbon to attract electrons more strongly as its 5 character increases. 

The structural facts that benzene is planai, all of the bond angles are 120°, and each carbon is bonded to three other atoms, suggest sp hybridization for carbon and the frane-work of a bonds shown in Figure 11.3<3. 

Each act of proton abstraction from the a carbon converts a chiral molecule to an achiral enol or enolate ion. The 5/) -hybridized carbon that is the chirality center in the starting ketone becomes 5/) -hybridized in the enol or enolate. Careful kinetic studies have established that the rate of loss of optical activity of 5cc-butyl phenyl ketone is equal to its rate of hydrogen-deuterium exchange, its rate of bromination, and its rate of iodina-tion. In each case, the rate-detennining step is conversion of the starting ketone to the enol or enolate anion. 

FIGURE 19.1 Carbon -W and both oxygens are sp -hybridized in formic acid. 

Because carbon is 5/) -hybridized in chlorobenzene, it is more electronegative than the 5/) -hybridized carbon of chlorocyclohexane. Consequently, the withdrawal of electron density away from carbon by chlorine is less pronounced in ar-yl halides than in alkyl halides, and the molecular- dipole moment is smaller. 

In diamond, each carbon atom forms single bonds with four other carbon atoms arranged tetrahedrally around it The hybridization in diamond is sp3. The three-dimensional covalent bonding contributes to diamond s unusual hardness. Diamond is one of the hardest substances known it is used in cutting tools and quality grindstones (Figure 9.12). 

The 13C NMR data for representative three-membered sulfones and sulfoxides are given in Table 5. The chemical shifts of the sp3-hybridized a-carbon in the parent thiirane70 and the five-membered ring86 sulfide, sulfoxide and sulfone are 18.1, 31.7, 54.3 and 51.1, respectively, whereas those of cyclopropenone, diphenylcyclopropenone and dimethylcyclopropenone are 169.087, 148.788 and 157.9, respectively. 

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