TABLE 12-1 Bond Stretching Frequencies Bond Energy Stretching Frequency Bond [kcal (kJ)] (cm-) Frequency dependence on atomic masses C一H 100(420) 3000 C一D heavier 100(420) 2100 decreases C一C atoms 83 (350) 1200↓ Frequency dependence on bond energies C-C 83 (350) 1200 stronger C=C 146 (611) bond 1660 7 increases CC 200 (840) 2200V C-N 73 (305) 1200 C=N 147 (615) 1650 C=N 213 (891) 2200J C-0 86 (360) 1100 C=0 178 (745)↓ 1700↓ Note:In a group of bonds with similar bond energies,the frequency decreases with increasing atomic weight.In a group of bonds between similar atoms,the frequency increases with bond energy.Bond energies and frequencies are approximate