328 PECTROSCOPY (c) The chemical shift of the eight equivalent hydrogens in C&Hs is 8 5.8 ppm, which is consistent with protons attached to a carbon-carbon double bond 1,3, 5, 7-Cyclooctatetraene (658ppm) (d) The compound CAHg Br has no rings or double bonds. The nine hydrogens belong to three equivalent methyl groups. (CH),CBI r-Butyl bromide(8 1. 8 ppm) (e) The dichloride has no rings or double bonds (index of hydrogen deficiency =0). The four equivalent hydrogens are present as two-CH, CI groups CICH, CH,CI 1. 2-Dichloroethane(8.7 ppm) (f) All three hydrogens in C2H3Cl3 must be part of the same methyl group in order to be CH3CCl3 I, 1, 1-Trichloroethane(8 2.7 ppm) (g) This compound has no rings or double bonds. To have eight equivalent hydrogens it must have our equ valent methyl ene grou CICHCCHCI 1.3-Dichloro-2, 2-di(chloromethyDpropane (63.7ppm (h) A compound with a molecular formula of CnHi has an index of hydrogen deficiency of 4 A likely candidate for a compound with 18 equivalent hydrogens is one with six equivalent CHs groups. Thus, 6 of the 12 carbons belong to CH3 groups, and the other 6 have no hydr gens. The compound is hexamethy benzene. HC A chemical shift of 8 2.2 ppm is consistent with the fact that all of the protons are benzylic ovens (i) The molecular formula of C3H, Br, tells us that the compound has no double bonds and no gs. All six hydrogens are equivalent, indicating two equivalent methyl groups. The com- pound is 2,2-dibromopropane,(CH3)2,CBr2 Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE Website(c) The chemical shift of the eight equivalent hydrogens in C8H8 is 5.8 ppm, which is consistent with protons attached to a carbon–carbon double bond. (d) The compound C4H9Br has no rings or double bonds. The nine hydrogens belong to three equivalent methyl groups. (CH3)3CBr tert-Butyl bromide ( 1.8 ppm) (e) The dichloride has no rings or double bonds (index of hydrogen deficiency 0). The four equivalent hydrogens are present as two GCH2Cl groups. ClCH2CH2Cl 1,2-Dichloroethane ( 3.7 ppm) ( f ) All three hydrogens in C2H3Cl3 must be part of the same methyl group in order to be equivalent. CH3CCl3 1,1,1-Trichloroethane ( 2.7 ppm) (g) This compound has no rings or double bonds. To have eight equivalent hydrogens it must have four equivalent methylene groups. (h) A compound with a molecular formula of C12H18 has an index of hydrogen deficiency of 4. A likely candidate for a compound with 18 equivalent hydrogens is one with six equivalent CH3 groups. Thus, 6 of the 12 carbons belong to CH3 groups, and the other 6 have no hydro￾gens. The compound is hexamethylbenzene. A chemical shift of 2.2 ppm is consistent with the fact that all of the protons are benzylic hydrogens. (i) The molecular formula of C3H6Br2 tells us that the compound has no double bonds and no rings. All six hydrogens are equivalent, indicating two equivalent methyl groups. The com￾pound is 2,2-dibromopropane, (CH3)2CBr2. CH3 CH3 CH3 H3C CH3 H3C ClCH2CCH2Cl CH2Cl CH2Cl 1,3-Dichloro-2,2-di(chloromethyl)propane ( 3.7 ppm) 1,3,5,7-Cyclooctatetraene ( 5.8 ppm) 328 SPECTROSCOPY Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website