SPECTROSCOPY 323 (f) The protons of a single methyl group are equivalent to one another, but all three methyl groups of 2-methyl-2-butene are nonequivalent. The vinyl proton is uniqu H,C H-C 2-Methyl-2-butene(four signals in the H NMR spectrum 13.8(b) The three methyl protons of 1, 1, 1-trichloroethane(Cl3CCH3) are equivalent. They have the same chemical shift and do not split each others signals. The H NMR spectrum of Cl,CCH3 consists of a single sharp peak (c) Separate signals will be seen for the methylene( CH,) protons and for the methine( Ch)pro- ton of 1.1. 2-trichloroethane Cl1C—CH,C The methine proton splits the signal for the methylene protons into a doublet. The two methylene protons split the methine protons signal into a triplet. (d) Examine the structure of 1, 2, 2-trichloropropane CICH, CCH3 1, 2, 2-Trichloropropane The"H NMR spectrum exhibits a signal for the two equivalent methylene protons and one for the three equivalent methyl protons. Both these signals are sharp singlets. The protons of the methyl group and the methylene group are separated by more than three bonds and do not split ach other's signals (e) The methine proton of 1, 1, 1, 2-tetrachloropropane splits the signal of the methyl protons into a doublet; its signal is split into a quartet by the three methyl protons CICC--CHaDoublet Quartet 1, 1, 1, 2-Tetrachloropropane 13.9(b) The ethyl group appears as a triplet- quartet pattern and the methyl group as a singlet CHaCH,OCH3 Singlet; not vicinal to any other protons in molecule Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE Website( f ) The protons of a single methyl group are equivalent to one another, but all three methyl groups of 2-methyl-2-butene are nonequivalent. The vinyl proton is unique. 13.8 (b) The three methyl protons of 1,1,1-trichloroethane (Cl3CCH3) are equivalent. They have the same chemical shift and do not split each other’s signals. The 1 H NMR spectrum of Cl3CCH3 consists of a single sharp peak. (c) Separate signals will be seen for the methylene (CH2) protons and for the methine (CH) pro￾ton of 1,1,2-trichloroethane. The methine proton splits the signal for the methylene protons into a doublet. The two methylene protons split the methine proton’s signal into a triplet. (d) Examine the structure of 1,2,2-trichloropropane. The 1 H NMR spectrum exhibits a signal for the two equivalent methylene protons and one for the three equivalent methyl protons. Both these signals are sharp singlets. The protons of the methyl group and the methylene group are separated by more than three bonds and do not split each other’s signals. (e) The methine proton of 1,1,1,2-tetrachloropropane splits the signal of the methyl protons into a doublet; its signal is split into a quartet by the three methyl protons. 13.9 (b) The ethyl group appears as a triplet–quartet pattern and the methyl group as a singlet. CH3CH2OCH3 Quartet Singlet; not vicinal to any other protons in molecule Triplet H Cl Cl3CC CH3 Doublet Quartet 1,1,1,2-Tetrachloropropane ClCH2CCH3 Cl Cl 1,2,2-Trichloropropane H Cl2C CH2Cl Triplet Doublet 1,1,2-Trichloroethane 2-Methyl-2-butene (four signals in the 1 H NMR spectrum) C C H3C CH3 H3C H SPECTROSCOPY 323 Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website