7512J. Org. Chem. 1997, 62, 7512-7515
NMR Chemical Shifts of Common Laboratory Solvents as Trace Impurities
Hugo E. Gottlieb,*Vadim Kotlyar, and
Abraham Nudelman*
Department of Chemistry, Bar-Ilan University,
Ramat-Gan 52900, Israel
Received June 27, 1997
In the course of the routine use of NMR as an aid for organic chemistry, a day-to-day problem is the identifica-tion of signals deriving from common contaminants (water,solvents, stabilizers, oils) in less-than-analyti-cally-pure samples. This data may be available in the literature, but the time involved in searching for it may be considerable. Another issue is the concentration dependence of chemical shifts (especially1H); results obtained two or three decades ago usually refer to much more concentrated samples, and run at lower magnetic fields, than today’spractice.
We therefore decided to collect 1H and 13C chemical shifts of what are, in our experience, the most popular “extrapeaks”in a variety of commonly used NMR solvents, in the hope that this will be of assistance to the practicing chemist.
Experimental Section
NMR spectra were taken in a Bruker DPX-300instrument (300.1and 75.5MHz for 1H and 13C, respectively). Unless otherwise indicated, all were run at room temperature (24(1°C).For the experiments in the last section of this paper, probe temperatures were measured with a calibrated Eurotherm 840/Tdigital thermometer, connected to a thermocouple which was introduced into an NMR tube filled with mineral oil to ap-proximately the same level as a typical sample. At each temperature, the D 2O samples were left to equilibrate for at least 10min before the data were collected.
In order to avoid having to obtain hundreds of spectra, we prepared seven stock solutions containing approximately equal amounts of several of our entries, chosen in such a way as to prevent intermolecular interactions and possible ambiguities in assignment. Solution 1:acetone, tert -butyl methyl ether, di-methylformamide, ethanol, toluene. Solution 2:benzene, di-methyl sulfoxide, ethyl acetate, methanol. Solution 3:acetic acid, chloroform, diethyl ether, 2-propanol, tetrahydrofuran. Solution 4:acetonitrile, dichloromethane, dioxane, n -hexane, HMPA. Solution 5:1,2-dichloroethane, ethyl methyl ketone, n -pentane, pyridine. Solution 6:tert -butyl alcohol, BHT, cyclo-hexane, 1,2-dimethoxyethane, nitromethane, silicone grease, triethylamine. Solution 7:diglyme, dimethylacetamide, ethyl-ene glycol, “grease”(engineoil). For D 2O. Solution 1:acetone, tert -butyl methyl ether, dimethylformamide, ethanol, 2-propanol. Solution 2:dimethyl sulfoxide, ethyl acetate, ethylene glycol, methanol. Solution 3:acetonitrile, diglyme, dioxane, HMPA, pyridine. Solution 4:1,2-dimethoxyethane, dimethylacetamide, ethyl methyl ketone, triethylamine. Solution 5:acetic acid, tert -butyl alcohol, diethyl ether, tetrahydrofuran. In D 2O and CD 3OD nitromethane was run separately, as the protons exchanged with deuterium in presence of triethylamine.
Results
Proton Spectra (Table1). A sample of 0.6mL of the solvent, containing 1µL of TMS, 1was first run on its own. From this spectrum we determined the chemical shifts of the solvent residual peak 2and the water peak. It should be noted that the latter is quite temperature-(1)For recommendations on the publication of NMR data, see:IUPAC Commission on Molecular Structure and Spectroscopy. Pure Appl. Chem. 1972, 29, 627; 1976, 45, 217.
S0022-3263(97)01176-6CCC:$14.00Figure 1. Chemical shift of H DO as a function of tempera-ture.
dependent (vide infra ). Also, any potential hydrogen-bond acceptor will tend to shift the water signal down-field; this is particularly true for nonpolar solvents. In contrast, in e.g. DMSO the water is already strongly hydrogen-bonded to the solvent, and solutes have only a negligible effect on its chemical shift. This is also true for D 2O; the chemical shift of the residual HDO is very temperature-dependent (vide infra ) but, maybe counter-intuitively, remarkably solute (andpH) independent. We then added 3µL of one of our stock solutions to the NMR tube. The chemical shifts were read and are presented in Table 1. Except where indicated, the coupling constants, and therefore the peak shapes, are essentially solvent-independent and are presented only once.
For D 2O as a solvent, the accepted reference peak (δ) 0) is the methyl signal of the sodium salt of 3-(trimeth-ylsilyl)propanesulfonic acid; one crystal of this was added to each NMR tube. This material has several disadvan-tages, however:it is not volatile, so it cannot be readily eliminated if the sample has to be recovered. In addition, unless one purchases it in the relatively expensive deuterated form, it adds three more signals to the spectrum (methylenes1, 2, and 3appear at 2.91, 1.76, and 0.63ppm, respectively). We suggest that the re-sidual HDO peak be used as a secondary reference; we find that if the effects of temperature are taken into account (vide infra ), this is very reproducible. For D 2O, we used a different set of stock solutions, since many of the less polar substrates are not significantly water-soluble (seeTable 1). We also ran sodium acetate and sodium formate (chemicalshifts:1.90and 8.44ppm, respectively).
Carbon Spectra (Table2). To each tube, 50µL of the stock solution and 3µL of TMS 1were added. The solvent chemical shifts 3were obtained from the spectra containing the solutes, and the ranges of chemical shifts
(2)I.e. , the signal of the proton for the isotopomer with one less deuterium than the perdeuterated material, e.g. , C H Cl 3in CDCl 3or C 6D 5H in C 6D 6. Except for CHCl 3, the splitting due to J HD is typically observed (toa good approximation, it is 1/6.5of the value of the corresponding J HH ). For CHD 2groups (deuteratedacetone, DMSO, acetonitrile), this signal is a 1:2:3:2:1quintet with a splitting of ca . 2Hz.
(3)In contrast to what was said in note 2, in the 13C spectra the solvent signal is due to the perdeuterated isotopomer, and the one-bond couplings to deuterium are always observable (ca . 20-30Hz).
©1997American Chemical Society
Notes
Table 1.
proton
solvent residual peak H 2O
acetic acid acetone acetonitrile benzene
tert -butyl alcohol tert -butyl methyl ether BHT b
mult s s s s s s s s s s s s s s s s s t, 7q, 7m m s s s s s s s s s s s t, 7q, 7d s c,d s q, 7t, 7s q, 7t, 7s e m br s t m d, 9.5s h s c,h s t, 7m d, 6sep, 6m m m s m m s m m t,7q, 7
CDCl 37.261.562.102.172.107.361.281.193.226.985.012.271.437.261.433.735.301.213.483.653.573.393.403.552.093.022.948.022.962.882.623.711.253.721.322.054.121.262.142.461.063.760.861.260.881.262.653.491.094.330.881.271.224.048.627.297.680.071.853.762.367.177.251.032.53
1H
J. Org. Chem., Vol. 62, No. 21, 19977513
NMR Data
(CD3) 2SO 2.503.33a 1.912.092.077.371.114.191.113.086.876.652.181.368.321.403.905.761.093.383.513.383.243.243.431.962.942.787.952.892.732.543.571.063.444.631.994.031.172.072.430.913.340.861.252.533.164.014.420.861.271.043.788.587.397.791.763.602.307.187.250.932.43
C 6D 67.160.401.551.551.557.151.051.551.073.047.054.792.241.386.151.402.904.271.113.263.463.343.113.123.331.602.572.057.632.361.861.683.350.963.341.653.890.921.581.810.853.410.921.360.891.242.403.072.940.871.230.953.678.536.666.980.291.403.572.117.027.130.962.40
CD 3CN 1.942.131.962.081.967.371.162.181.143.136.975.202.221.397.581.443.815.441.123.423.533.453.293.283.451.972.962.837.922.892.772.503.601.123.542.471.974.061.202.062.430.963.510.861.270.891.282.573.282.164.310.891.291.093.878.577.337.730.081.803.642.337.1-7.37.1-7.30.962.45
CD 3OD 3.314.871.992.152.037.331.401.153.206.922.211.407.901.453.785.491.183.493.613.583.353.353.522.073.312.927.972.992.862.653.661.193.602.014.091.242.122.501.013.590.881.290.901.292.643.344.340.901.291.503.928.537.447.850.101.873.712.327.167.161.052.58
D 2O 4.792.082.222.061.241.213.22
(CD3) 2CO 2.052.84a 1.962.092.057.361.181.133.136.962.221.418.021.433.875.631.113.413.563.473.283.283.461.973.002.837.962.942.782.523.591.123.573.391.974.051.202.072.450.963.280.871.290.881.282.593.313.124.430.881.271.103.908.587.357.760.131.793.632.327.1-7.27.1-7.20.962.45
chloroform cyclohexane
1,2-dichloroethane dichloromethane diethyl ether diglyme
1,2-dimethoxyethane dimethylacetamide dimethylformamide dimethyl sulfoxide dioxane ethanol ethyl acetate ethyl methyl ketone ethylene glycol “grease”f n -hexane HMPA g methanol nitromethane n -pentane 2-propanol pyridine silicone grease i tetrahydrofuran toluene triethylamine
a
CH 3CH 3CH 3CH CH 3OH c CCH 3OCH 3ArH OH c ArCH 3
ArC(CH3) 3CH CH 2CH 2CH 2CH 3CH 2CH 2CH 2OCH 3CH 3CH 2
CH 3CO NCH 3NCH 3CH CH 3CH 3CH 3CH 2CH 3CH 2OH CH 3CO C H 2CH 3CH 2C H 3CH 3CO C H 2CH 3CH 2C H 3CH CH 3CH 2CH 3CH 2CH 3CH 3OH CH 3CH 3CH 2CH 3CH CH(2)CH(3)CH(4)CH 3CH 2CH 2O CH 3
CH(o/p) CH(m ) CH 3CH 2
1.173.563.673.613.373.373.602.083.062.907.923.012.852.713.751.173.652.074.141.242.193.181.263.65
2.613.344.401.174.028.527.457.871.883.74
0.992.57
In these solvents the intermolecular rate of exchange is slow enough that a peak due to HDO is usually also observed; it appears at 2.81and 3.30ppm in acetone and DMSO, respectively. In the former solvent, it is often seen as a 1:1:1triplet, with 2J H,D ) 1Hz. b 2,6-Dimethyl-4-tert -butylphenol. c The signals from exchangeable protons were not always identified. d In some cases (seenote a ), the coupling interaction between the CH 2and the OH protons may be observed (J ) 5Hz). e In CD 3CN, the OH proton was seen as a multiplet at δ2.69, and extra coupling was also apparent on the methylene peak. f Long-chain, linear aliphatic hydrocarbons. Their solubility in DMSO was too low to give visible peaks. g Hexamethylphosphoramide. h In some cases (seenotes a , d ), the coupling interaction between the CH 3and the OH protons may be observed (J ) 5.5Hz). i Poly(dimethylsiloxane).Its solubility in DMSO was too low to give visible peaks.
show their degree of variability. Occasionally, in order to distinguish between peaks whose assignment was ambiguous, a further 1-2µL of a specific substrate were added and the spectra run again.
7514J. Org. Chem., Vol. 62, No. 21, 1997
Table 2.
CDCl 3
solvent signals
13C
Notes
NMR Data a (CD3) 2SO
C 6D 6
CD 3CN 1.32(0.02118.26(0.02CD 3OD 49.00(0.01D 2O
(CD3) 2CO 29.84(0.01206.26(0.1377.16(0.0639.52(0.06128.06(0.02acetic acid
CO 175.99172.31171.93CH 3
20.8120.5120.95acetone CO
207.07205.87206.31CH 3
30.9230.6030.56acetonitrile CN
116.43117.60117.91CH 3
1.891.121.03benzene CH 128.37129.15128.30tert -butyl alcohol C
69.1568.1366.88CH 3
31.2530.7230.38tert -butyl methyl ether OCH 3
49.4549.3548.70C 72.8772.8172.04C C H 3
26.9927.2426.79BHT C(1)
151.55152.51151.47C(2)135.87138.19139.12CH(3)125.55129.05127.97C(4)128.27126.03124.85CH 3Ar 21.2021.3120.97C H 3C 30.3331.6131.25C
34.2535.0034.33chloroform CH 77.3679.1979.16cyclohexane CH 226.9427.5126.331,2-dichloroethane CH 243.5045.2545.02dichloromethane CH 253.5254.9554.84diethyl ether CH 3
15.2015.7815.12CH 2
65.9166.1262.05diglyme CH 3
59.0158.7757.98CH 270.5171.0369.54CH 2
71.9072.6371.251,2-dimethoxyethane CH 3
59.0858.4558.01CH 2
71.8472.4717.07dimethylacetamide CH 3
21.5321.5121.29CO 171.07170.61169.54NCH 335.2834.8937.38NCH 3
38.1337.9234.42dimethylformamide CH
162.62162.79162.29CH 336.5036.1535.73CH 3
31.4531.0330.73dimethyl sulfoxide CH 340.7641.2340.45dioxane CH 267.1467.6066.36ethanol CH 3
18.4118.8918.51CH 2
58.2857.7256.07ethyl acetate C H 3CO
21.0420.8320.68CO 171.36170.96170.31CH 260.4960.5659.74CH 3
14.1914.5014.40ethyl methyl ketone C H 3CO
29.4929.3029.26CO
209.56208.30208.72C H 2CH 336.8936.7535.83CH 2C H 3
7.868.037.61ethylene glycol CH 263.7964.2662.76“grease”CH 229.7630.7329.20n -hexane CH 3
14.1414.3413.88CH 2(2)22.7023.2822.05CH 2(3)
31.6432.3030.95HMPA b CH 3
36.8737.0436.42methanol CH 350.4149.7748.59nitromethane CH 362.5063.2163.28n -pentane CH 3
14.0814.2913.28CH 2(2)22.3822.9821.70CH 2(3)
34.1634.8333.482-propanol CH 3
25.1425.6725.43CH
64.5063.8564.92pyridine CH(2)
149.90150.67149.58CH(3)123.75124.57123.84CH(4)
135.96136.56136.05silicone grease CH 31.041.40tetrahydrofuran CH 2
25.6226.1525.14CH 2O
67.9768.0767.03toluene CH 3
21.4621.4620.99C(i ) 137.89138.48137.35CH(o ) 129.07129.76128.88CH(m ) 128.26129.03128.18CH(p )
125.33126.12125.29triethylamine CH 3
11.6112.4911.74CH 2
46.25
47.07
45.74
a
See footnotes for Table 1. b 2J PC ) 3Hz. c Reference material; see text.
175.82173.2120.3720.73204.43207.4330.1430.91116.02118.260.201.79128.62129.3268.1968.7430.4730.6849.1949.5272.4073.1727.0927.28152.05152.42136.08138.13128.52129.61125.83126.3821.4021.2331.3431.5034.3535.0577.7979.1727.2327.6343.5945.5453.4655.3215.4615.6365.9466.3258.6658.9070.8770.9972.3572.6358.6858.8972.2172.4721.1621.76169.95171.3134.6735.1737.0338.26162.13163.3135.2536.5730.7231.3240.0341.3167.1667.7218.7218.8057.8657.9620.5621.16170.44171.6860.2160.9814.1914.5428.5629.60206.55209.8836.3637.097.918.1464.3464.2230.2130.8614.3214.4323.0423.4031.9632.3636.8837.1049.9749.9061.1663.6614.2514.3722.7223.0834.4534.8925.1825.5564.2364.30150.27150.76123.58127.76135.28136.891.3825.7226.2767.8068.3321.1021.50137.91138.90129.33129.94128.56129.23125.68126.2812.3512.3846.77
47.10
175.11177.2120.5621.03209.67215.9430.6730.89118.06119.680.851.47129.3469.4070.3630.9130.2949.6649.3774.3275.6227.2226.60152.85139.09129.49126.1121.3831.1535.3679.4427.9645.1154.7815.4614.7766.8866.4259.0658.6771.3370.0572.9271.6359.0658.6772.7271.4921.3221.09173.32174.5735.5035.0338.4338.76164.73165.5336.8937.5431.6132.0340.4539.3968.1167.1918.4017.4758.2658.0520.8821.15172.89175.2661.5062.3214.4913.9229.3929.49212.16218.4337.3437.278.097.8764.3063.17
31.2914.4523.6832.7337.0036.4649.8649.50c 63.0863.22
14.3923.3835.3025.2724.3864.7164.88150.07149.18125.53125.12138.35138.272.1026.4825.6768.8368.68
21.50138.85129.91129.20126.2911.099.0746.96
47.19
Notes For D 2O solutions there is no accepted reference for carbon chemical shifts. We suggest the addition of a drop of methanol, and the position of its signal to be defined as 49.50ppm; on this basis, the entries in Table 2were recorded. The chemical shifts thus obtained are, on the whole, very similar to those for the other solvents. Alternatively, we suggest the use of dioxane when the methanol peak is expected to fall in a crowded area of the spectrum. We also report the chemical shifts of sodium formate (171.67ppm), sodium acetate (182.02and 23.97ppm), sodium carbonate (168.88ppm), sodium bicarbonate (161.08ppm), and sodium 3-(trimethylsilyl)-propanesulfonate [54.90,19.66, 15.56(methylenes1, 2, and 3, respectively), and -2.04ppm (methyls)],in D 2O. Temperature Dependence of HDO Chemical Shifts. We recorded the 1H spectrum of a sample of D 2O, containing a crystal of sodium 3-(trimethylsilyl)propane-sulfonate as reference, as a function of temperature. The
J. Org. Chem., Vol. 62, No. 21, 19977515
data are shown in Figure 1. The solid line connecting the experimental points corresponds to the equation
δ) 5.060-0.0122T +(2.11×10-5) T 2
(1)
which reproduces the measured values to better than 1ppb. For the 0-50o C range, the simpler
δ) 5.051-0.0111T (2)
gives values correct to 10ppb. For both equations, T is the temperature in °C.
Acknowledgment. Generous support for this work by the Minerva Foundation and the Otto Mayerhoff Center for the Study of Drug -Receptor Interactions at Bar-Ilan University is gratefully acknowledged.
JO971176V
常用氘代溶剂和杂质峰在1H 谱中的化学位移
测试核磁的样品一般要求比较纯,并且能够溶解在氘代试剂中,这样才能测得高分辨率的图谱。
为不干扰谱图,所用溶剂分子中的氢都应被氘取代,但难免有氢的残余(1%左右),这样就会产生溶剂峰;除了残存的质子峰外,溶剂中有时会有微量的H2O 而产生水峰,而且这个H2O 峰的位置也会因溶剂的不同而不同;另外,在样品(或制备过程)中,也难免会残留一些杂质,在图谱上就会有杂质峰,应注意识别。以下给出了一些常见溶剂峰和杂质峰的化学位移:
常用氘代溶剂和杂质峰在1H 谱中的化学位移 单位:ppm
溶剂 — CDCl3 (CD3)2CO (CD3)2SO C6D6 CD3CN CD3OH 溶剂峰 — 7.26 2.05 2.49 7.16 1.94 3.31 4.80 水峰 — 1.56 2.84 3.33 0.40 2.13 4.87 — 乙酸 — 2.10 1.96 1.91 1.55 1.96 1.99 2.08 丙酮 — 2.17 2.09 2.09 1.55 2.08 2.15 2.22 乙腈 — 2.10 2.05 2.07 1.55 1.96 2.03 2.06 苯 — 7.36 7.36 7.37 7.15 7.37 7.33 —
叔丁醇 CH3 1.28 1.18 1.11 1.05 1.16 1.40 1.24 OH — — 4.19 1.55 2.18 — —
叔丁基甲醚 CCH3 1.19 1.13 1.11 1.07 1.14 1.15 1.21 OCH3 3.22 3.13 3.08 3.04 3.13 3.20 3.22 氯仿 — 7.26 8.02 8.32 6.15 7.58 7.90 — 环己烷 — 1.43 1.43 1.40 1.40 1.44 1.45 — 1,2-二氯甲烷 3.73 3.87 3.90 2.90 3.81 3.78 — 二氯甲烷 — 5.30 5.63 5.76 4.27 5.44 5.49 — 乙醚 CH3(t) 1.21 1.11 1.09 1.11 1.12 1.18 1.17 CH2(q) 3.48 3.41 3.38 3.26 3.42 3.49 3.56 二甲基甲酰胺CH 8.02 7.96 7.95 7.63 7.92 7.79 7.92 CH3 2.96 2.94 2.89 2.36 2.89 2.99 3.01 CH3 2.88 2.78 2.73 1.86 2.77 2.86 2.85 二甲基亚砜 — 2.62 2.52 2.54 1.68 2.50 2.65 2.71 二氧杂环 — 3.71 3.59 3.57 3.35 3.60 3.66 3.75 乙醇 CH3(t) 1.25 1.12 1.06 0.96 1.12 1.19 1.17 CH2(q) 3.72 3.57 3.44 3.34 3.54 3.60 3.65 OH(s) 1.32 3.39 3.63 — 2.47 — —
乙酸乙酯 CH3CO 2.05 1.97 1.99 1.65 1.97 2.01 2.07 OCH2(q) 4.12 4.05 4.03 3.89 4.06 4.09 4.14 CH3(t) 1.26 1.20 1.17 0.92 1.20 1.24 1.24 甲乙酮 CH3CO 2.14 2.07 2.07 1.58 2.06 2.12 2.19 CH2(q) 2.46 2.45 2.43 1.81 2.43 2.50 3.18 CH3(t) 1.06 0.96 0.91 0.85 0.96 1.01 1.26 乙二醇 — 3.76 3.28 3.34 3.41 3.51 3.59 3.65 润滑脂 CH3(m) 0.86 0.87 — 0.92 0.86 0.88 — CH2(br) 1.26 1.29 — 1.36 1.27 1.29 — 正己烷 CH3(t) 0.88 0.88 0.86 0.89 0.89 0.90 — CH2 (m) 1.26 1.28 1.25 1.24 1.28 1.29 — D2O
甲醇 CH3 3.49 3.31 3.16 3.07 3.28 3.34 3.34 OH 1.09 3.12 4.01 2.16 — —
正戊烷 CH3(t) 0.88 0.88 0.86 0.87 0.89 0.90 — CH2(m) 1.27 1.27 1.27 1.23 1.29 1.29 — 异丙醇 CH3(d) 1.22 1.10 1.04 0.95 1.09 1.50 1.17 CH 4.04 3.90 3.78 3.67 3.87 3.92 4.02 硅脂 — 0.07 0.13 — 0.29 0.08 0.10 — 四氢呋喃 CH2 1.85 1.79 1.76 1.40 1.80 1.87 1.88 CH2O 3.76 3.63 3.60 3.57 3.64 3.71 3.74 甲苯 CH3 2.36 2.32 2.30 2.11 2.33 2.32 — CH (o/p) 7.17 7.20 7.18 7.02 7.30 7.16 — CH (m ) 7.25 7.20 7.25 7.13 7.30 7.16 — 三乙基胺 CH3 1.03 0.96 0.93 0.96 0.96 1.05 0.99 CH2 2.53 2.45 2.43 2.40 2.45 2.58 2.57 石油醚 — 0.5-1.5 0.6-1.9 — — — — —
溶
剂 CDCl3 (CD3)2CO (CD3)2SO C6D6 CD3CN CD3OH D2O 溶剂峰 7.26 2.05 2.49 7.16 1.94 3.31 4.80 水峰 1.56 2.84 3.33 0.40 2.13 4.87 — 乙酸 2.10 1.96 1.91 1.55 1.96 1.99 2.08 丙酮 2.17 2.09 2.09 1.55 2.08 2.15 2.22 乙腈 2.10 2.05 2.07 1.55 1.96 2.03 2.06 苯 7.36 7.36 7.37 7.15 7.37 7.33 — 叔丁醇 CH3 1.28 1.18 1.11 1.05 1.16 1.40 1.24 OH — — 4.19 1.55 2.18 — — 叔丁基甲醚
CCH3 1.19 1.13 1.11 1.07 1.14 1.15 1.21
OCH3 3.22 3.13 3.08 3.04 3.13 3.20 3.22
氯仿 — 7.26 8.02 8.32 6.15 7.58 7.90 —
环己烷 — 1.43 1.43 1.40 1.40 1.44 1.45 — 1,2-二氯甲烷 3.73 3.87 3.90 2.90 3.81 3.78 —
二氯甲烷 — 5.30 5.63 5.76 4.27 5.44 5.49 — 乙醚 CH3(t) 1.21 1.11 1.09 1.11 1.12 1.18 1.17 CH2(q) 3.48 3.41 3.38 3.26 3.42 3.49 3.56 二甲基甲酰胺CH 8.02 7.96 7.95 7.63 7.92 7.79 7.92 CH3 2.96 2.94 2.89 2.36 2.89 2.99 3.01
CH3 2.88 2.78 2.73 1.86 2.77 2.86 2.85
二甲基亚砜 — 2.62 2.52 2.54 1.68 2.50 2.65 2.71 二氧杂环 — 3.71 3.59 3.57 3.35 3.60 3.66 3.75 乙醇 CH3(t) 1.25 1.12 1.06 0.96 1.12 1.19 1.17 CH2(q) 3.72 3.57 3.44 3.34 3.54 3.60 3.65 OH(s) 1.32 3.39 3.63 — 2.47 — —
乙酸乙酯 CH3CO 2.05 1.97 1.99 1.65 1.97 2.01 2.07 OCH2(q) 4.12 4.05 4.03 3.89 4.06 4.09 4.14 CH3(t) 1.26 1.20 1.17 0.92 1.20 1.24 1.24
甲乙酮 CH3CO 2.14 2.07 2.07 1.58 2.06 2.12 2.19 CH2(q) 2.46 2.45 2.43 1.81 2.43 2.50 3.18 CH3(t) 1.06 0.96 0.91 0.85 0.96 1.01 1.26 乙二醇 — 3.76 3.28 3.34 3.41 3.51 3.59 3.65 润滑脂 CH3(m) 0.86 0.87 — 0.92 0.86 0.88 — CH2(br) 1.26 1.29 — 1.36 1.27 1.29 —
正己烷 CH3(t) 0.88 0.88 0.86 0.89 0.89 0.90 — CH2 (m) 1.26 1.28 1.25 1.24 1.28 1.29 — 甲醇 CH3 3.49 3.31 3.16 3.07 3.28 3.34 3.34 OH 1.09 3.12 4.01 2.16 — —
正戊烷 CH3(t) 0.88 0.88 0.86 0.87 0.89 0.90 — CH2(m) 1.27 1.27 1.27 1.23 1.29 1.29 —
异丙醇 CH3(d) 1.22 1.10 1.04 0.95 1.09 1.50 1.17 CH 4.04 3.90 3.78 3.67 3.87 3.92 4.02
硅脂 — 0.07 0.13 — 0.29 0.08 0.10 —
四氢呋喃 CH2 1.85 1.79 1.76 1.40 1.80 1.87 1.88 CH2O 3.76 3.63 3.60 3.57 3.64 3.71 3.74 甲苯 CH3 2.36 2.32 2.30 2.11 2.33 2.32 — CH (o/p) 7.17 7.20 7.18 7.02 7.30 7.16 — CH (m ) 7.25 7.20 7.25 7.13 7.30 7.16 —
三乙基胺 CH3 1.03 0.96 0.93 0.96 0.96 1.05 0.99 CH2 2.53 2.45 2.43 2.40 2.45 2.58 2.57 石油醚 — 0.5-1.5 0.6-1.9 — — — — —
测试核磁的样品一般要求比较纯,并且能够溶解在氘代试剂中,这样才能测得高分辨率的图谱。
为不干扰谱图,所用溶剂分子中的氢都应被氘取代,但难免有氢的残余(1%左右),这样就会产生溶剂峰;除了残存的质子峰外,溶剂中有时会有微量的H 2O 而产生水峰,而且这个H 2O 峰的位置也会因溶剂的不同而不同;另外,在样
品(或制备过程)中,也难免会残留一些杂质,在图谱上就会有杂质峰,应注意识别。以下给出了一些常见溶剂峰和杂质峰的化学位移:
常用氘代溶剂和杂质峰在H 谱中的化学位移 单位:ppm 溶剂
溶剂峰
水峰
乙酸
丙酮
乙腈
苯
叔丁醇 — — — — — — — CDCl 33) 2CO (CD3) 2SO C 6D 63CN CD 32O 1— — CH 3OH — — — —
CCH 3OCH 3—
—
—
— — — — — 叔丁基甲醚 氯仿 环己烷 1,2-二氯甲烷 二氯甲烷
乙醚 CH 3CH 2CH 3CH 3二甲基甲酰胺
二甲基亚砜
二氧杂环
乙醇 — — CH 3CH 2— 2.47 — —
乙酸乙酯 CH 3OCH 2CH 3甲乙酮 CH 3CH 2CH 3乙二醇 —
润滑脂 CH 3CH 2— —
1.25 — — 1.24 1.28 1.29 正己烷
甲醇 CH 3— CH 2 (m) 1.26 1.28 — CH 3— — CH 3— CH 2— CH 3— — — 正戊烷 异丙醇 硅脂
四氢呋喃
甲苯 CH 2CH 2CH 3—
CH (o/p )
CH (m) — —
三乙基胺 CH 3CH 2—5-1.5 0.6-1.9 — — — — — 石油醚
常用氘代溶剂和杂质峰在1H 谱中的化学位移
测试核磁的样品一般要求比较纯,并且能够溶解在氘代试剂中,这样才能测得高分辨率的图谱。
为不干扰谱图,所用溶剂分子中的氢都应被氘取代,但难免有氢的残余(1%左右),这样就会产生溶剂峰;除了残存的质子峰外,溶剂中有时会有微量的H2O 而产生水峰,而且这个H2O 峰的位置也会因溶剂的不同而不同;另外,在样品(或制备过程)中,也难免会残留一些杂质,在图谱上就会有杂质峰,应注意识别。以下给出了一些常见溶剂峰和杂质峰的化学位移:
常用氘代溶剂和杂质峰在1H 谱中的化学位移 单位:ppm 溶
剂 — CDCl3 (CD3)2CO (CD3)2SO C6D6 CD3CN CD3OH D2O 溶剂
峰 — 7.26 2.05 2.49 7.16 1.94 3.31 4.80 水峰 — 1.56 2.84 3.33 0.40 2.13 4.87 — 乙酸 — 2.10 1.96 1.91 1.55 1.96 1.99 2.08 丙酮 — 2.17 2.09 2.09 1.55 2.08 2.15 2.22 乙腈 — 2.10 2.05 2.07 1.55 1.96 2.03 2.06 苯 — 7.36 7.36 7.37 7.15 7.37 7.33 — 叔丁
醇 CH3 1.28 1.18 1.11 1.05 1.16 1.40 1.24 OH — — 4.19 1.55 2.18 — — 叔丁基甲
醚 CCH3 1.19 1.13 1.11 1.07 1.14 1.15 1.21
OCH3 3.22 3.13 3.08 3.04 3.13 3.20 3.22 氯仿 — 7.26 8.02 8.32 6.15 7.58 7.90 — 环己烷 — 1.43 1.43 1.40 1.40 1.44 1.45 — 1,2-二氯甲烷 3.73 3.87 3.90 2.90 3.81 3.78 — 二氯甲
烷 — 5.30 5.63 5.76 4.27 5.44 5.49 — 乙
醚 CH3(t) 1.21 1.11 1.09 1.11 1.12 1.18 1. 17
CH2(q) 3.48 3.41 3.38 3.26 3.42 3.49 3.56 二甲基甲酰胺
CH 8.02 7.96 7.95 7.63 7.92 7.79 7.92 CH3 2.96 2.94 2.89 2.36 2.89 2.99 3.01 CH3 2.88 2.78 2.73 1.86 2.77 2.86 2.85 二甲基亚
砜 — 2.62 2.52 2.54 1.68 2.50 2.65 2.71
二氧杂
环 — 3.71 3.59 3.57 3.35 3.60 3.66 3.75 乙
醇 CH3(t) 1.25 1.12 1.06 0.96 1.12 1.19 1. 17
CH2(q) 3.72 3.57 3.44 3.34 3.54 3.60 3.65 OH(s) 1.32 3.39 3.63 — 2.47 — — 乙酸乙
酯 CH3CO 2.05 1.97 1.99 1.65 1.97 2.01 2. 07
OCH2(q) 4.12 4.05 4.03 3.89 4.06 4.09 4.14
CH3(t) 1.26 1.20 1.17 0.92 1.20 1.24 1.24 甲乙
酮 CH3CO 2.14 2.07 2.07 1.58 2.06 2.12 2. 19
CH2(q) 2.46 2.45 2.43 1.81 2.43 2.50 3.18 CH3(t) 1.06 0.96 0.91 0.85 0.96 1.01 1.26 乙二
醇 — 3.76 3.28 3.34 3.41 3.51 3.59 3.65 润滑
脂 CH3(m) 0.86 0.87 — 0.92 0.86 0.88 — CH2(br) 1.26 1.29 — 1.36 1.27 1.29 — 正己
烷 CH3(t) 0.88 0.88 0.86 0.89 0.89 0.90 — CH2 (m) 1.26 1.28 1.25 1.24 1.28 1.29 — 甲
醇 CH3 3.49 3.31 3.16 3.07 3.28 3.34 3.34 OH 1.09 3.12 4.01 2.16 — — 正戊
烷 CH3(t) 0.88 0.88 0.86 0.87 0.89 0.90 — CH2(m) 1.27 1.27 1.27 1.23 1.29 1.29 — 异丙
醇 CH3(d) 1.22 1.10 1.04 0.95 1.09 1.50 1. 17
CH 4.04 3.90 3.78 3.67 3.87 3.92 4.02 硅脂 — 0.07 0.13 — 0.29 0.08 0.10 — 四氢呋
喃 CH2 1.85 1.79 1.76 1.40 1.80 1.87 1.88 CH2O 3.76 3.63 3.60 3.57 3.64 3.71 3.74 甲苯 CH3 2.36 2.32 2.30 2.11 2.33 2.32 — (o/p) CH 7.17 7.20 7.18 7.02 7.30 7.16 —
CH (m ) 7.25 7.20 7.25 7.13 7.30 7.16 — 三乙基
胺 CH3 1.03 0.96 0.93 0.96 0.96 1.05 0.99 CH2 2.53 2.45 2.43 2.40 2.45 2.58 2.57
石油醚 — 0.5-1.5 0.6-1.9 — — — —
常见溶剂的化学位移
常见溶剂的1H 在不同氘代溶剂中的化学位移值
常见溶剂的化学位移
常见溶剂的13C 在不同氘代溶剂中的化学位移值