核磁共振化学位移表NMR tables — ¹H and ¹³C chemical shifts, couplings, solvents
化学位移 \(\delta = (\nu - \nu_{\text{ref}})/\nu_0 \times 10^6\) 反映核周围的电子屏蔽:电负性基团、π 体系的各向异性和氢键使核去屏蔽、移向低场(δ 增大)。下列范围为 CDCl₃ 中的典型值;溶剂、浓度、温度和氢键会使可交换质子(OH、NH、COOH)大幅移动。
The chemical shift \(\delta = (\nu - \nu_{\text{ref}})/\nu_0 \times 10^6\) reflects electronic shielding: electronegative groups, π-system anisotropy and hydrogen bonding deshield nuclei and move them downfield (larger δ). Ranges are typical for CDCl₃; solvent, concentration, temperature and H-bonding shift exchangeable protons (OH, NH, COOH) widely.
¹H 化学位移¹H chemical shifts
绿色标出的 H 就是所指的质子;R = H 或烷基,X = O、N 或卤素。The highlighted H is the proton in question; R = H or alkyl, X = O, N or halogen.
饱和 C–H(R = H 或烷基)Saturated C–H (R = H or alkyl)
杂原子 α 位与 sp² C–Hα to heteroatoms, sp² C–H
可交换质子(位置随浓度、溶剂变化)Exchangeable H (vary with concentration & solvent)
完整查表 Full look-up table
| 质子 / 碳类型 Environment | δ / ppm | 说明 Notes |
|---|---|---|
| TMS(参比)TMS (reference) | 0 | |
| 环丙烷 CHCyclopropane CH | 0.2–0.6 | 环电流屏蔽ring-current shielding |
| 金属–H / 硅–CH₃Si–CH₃, M–CH₃ | −0.1–0.3 | |
| 烷基 CH₃Alkyl CH₃ | 0.8–1 | |
| 烷基 CH₂Alkyl CH₂ | 1.2–1.4 | |
| 烷基 CHAlkyl CH | 1.4–1.7 | |
| 烯丙位 C–HAllylic C–H | 1.6–2.2 | |
| 羰基 α-Hα to C=O | 2–2.6 | 甲基酮 CH₃ 约 2.1,乙酸酯 CH₃ 约 2.0methyl ketone ≈2.1, acetate ≈2.0 |
| 苄位 C–HBenzylic C–H | 2.2–2.8 | 甲苯 CH₃ 2.35toluene CH₃ 2.35 |
| 炔氢Alkyne ≡C–H | 1.8–3.1 | 受三键各向异性屏蔽shielded by the triple-bond anisotropy |
| 胺 N–CHN–CH (amines) | 2.2–2.9 | |
| 硫醚 / 硫醇 S–CHS–CH | 2–2.6 | |
| 卤代 C–H (Cl, Br, I)C–H α to Cl, Br, I | 2.1–4.2 | CH₃I 2.16,CH₃Br 2.68,CH₃Cl 3.05CH₃I 2.16, CH₃Br 2.68, CH₃Cl 3.05 |
| 醇、醚 O–CHO–CH (alcohols, ethers) | 3.3–4 | 甲氧基约 3.3–3.8methoxy ≈3.3–3.8 |
| 酯 O–CH (–C(O)O–CH)Ester O–CH | 3.7–4.4 | 乙酸乙酯 OCH₂ 4.12ethyl acetate OCH₂ 4.12 |
| 氟代 CH (F–CH)F–CH | 4.2–4.8 | |
| 硝基 α-CHCH α to NO₂ | 4.2–4.6 | |
| 醇 O–HAlcohol O–H | 0.5–5 | 可交换、宽,位置随浓度变;D₂O 交换后消失exchangeable, broad, concentration-dependent; vanishes with D₂O |
| 胺 N–HAmine N–H | 0.5–3 | 可交换exchangeable |
| 烯烃 =C–HVinylic =C–H | 4.5–6.5 | 端烯 =CH₂ 4.6–5.0;共轭使其去屏蔽terminal =CH₂ 4.6–5.0; conjugation deshields |
| 烯醇醚 / 烯胺 =C–HEnol ether =CH–O | 6–6.6 | |
| α,β-不饱和羰基 β-Hβ-H of enone | 6.5–7.5 | |
| 芳香 HAromatic H | 6.5–8 | 苯 7.36(CDCl₃);吸电子基使邻、对位去屏蔽benzene 7.36 (CDCl₃); EWGs deshield ortho/para |
| 杂芳 H(吡啶 α-H)Heteroaromatic H (pyridine α) | 7–9 | 吡啶 α-H 约 8.6pyridine α-H ≈ 8.6 |
| 酚 O–HPhenol O–H | 4–7.5 | 分子内氢键时可达 10–12up to 10–12 with intramolecular H-bonds |
| 酰胺 N–HAmide N–H | 5–8.5 | 常宽;DMSO-d₆ 中更清楚often broad; clearer in DMSO-d₆ |
| 甲酰胺 / 甲酸酯 H–C(O)–N/OFormyl H–C(O)N / H–C(O)O | 8–8.2 | |
| 醛 HAldehyde CHO | 9.4–10.1 | 与 α-H 的 ³J 约 1–3 Hz³J to α-H ≈ 1–3 Hz |
| 羧酸 O–HCarboxylic acid O–H | 10–13 | 很宽,可交换very broad, exchangeable |
| 烯醇 O–H(β-二酮)Enol O–H (β-diketone) | 11–17 | 强分子内氢键strong intramolecular H-bond |
¹³C 化学位移¹³C chemical shifts
绿色标出的是所指的碳。The highlighted atom is the carbon in question.
sp³ 碳sp³ carbons
sp / sp² 碳sp & sp² carbons
羰基碳Carbonyl carbons
完整查表 Full look-up table
| 质子 / 碳类型 Environment | δ / ppm | 说明 Notes |
|---|---|---|
| TMS(参比)TMS (reference) | 0 | |
| 烷基 CH₃Alkyl CH₃ | 5–30 | |
| 烷基 CH₂Alkyl CH₂ | 15–45 | |
| 烷基 CH / 季碳Alkyl CH / Cq | 25–55 | |
| C–IC–I | −20–10 | 重原子效应使其高场heavy-atom effect shields it |
| C–BrC–Br | 10–40 | |
| C–ClC–Cl | 25–50 | |
| C–N(胺)C–N (amines) | 30–65 | |
| C–SC–S | 10–40 | |
| C–O(醇、醚)C–O (alcohols, ethers) | 50–85 | OCH₃ 约 55–60OCH₃ ≈ 55–60 |
| C–FC–F | 70–100 | ¹J(C,F) 约 160–250 Hz,呈双峰¹J(C,F) ≈ 160–250 Hz doublet |
| 缩醛 / 缩酮 O–C–OAcetal / ketal O–C–O | 90–110 | 糖的异头碳约 90–105sugar anomeric C ≈ 90–105 |
| 炔碳 C≡CAlkyne C≡C | 65–90 | |
| 腈 C≡NNitrile C≡N | 110–125 | |
| 烯碳 C=CAlkene C=C | 100–150 | |
| 芳碳Aromatic C | 110–160 | 苯 128.4;C–O 芳碳约 155–160benzene 128.4; aryl C–O ≈ 155–160 |
| 杂芳碳Heteroaromatic C | 105–165 | |
| 丙二烯中心碳Allene central C | 195–215 | |
| 酸酐、酯、内酯 C=OEster / lactone / anhydride C=O | 160–180 | |
| 酰胺 C=OAmide C=O | 160–180 | |
| 羧酸 C=OCarboxylic acid C=O | 170–185 | |
| 酰氯 C=OAcyl chloride C=O | 165–175 | |
| 碳酸酯、脲、氨基甲酸酯 C=OCarbonate / urea / carbamate C=O | 150–160 | |
| 醛 C=OAldehyde C=O | 190–205 | |
| 酮 C=OKetone C=O | 195–220 | 共轭酮约 190–200conjugated ≈ 190–200 |
| 亚胺 / 肟 C=NImine / oxime C=N | 145–170 | |
| 金属羰基 M–COMetal carbonyl | 180–230 |
典型偶合常数Typical coupling constants
| 体系 System | J / Hz | 说明 Notes |
|---|---|---|
| 同碳偕偶 ²J(sp³ CH₂)Geminal ²J (sp³ CH₂) | −10 – −15 | 非对映 CH₂ 才显现seen only for diastereotopic CH₂ |
| 邻位 ³J,自由旋转烷基链Vicinal ³J, free-rotating chain | 6 – 8 | 乙基 CH₂–CH₃ 约 7ethyl ≈ 7 |
| 邻位 ³J,环己烷 ax–axVicinal ³J, cyclohexane ax–ax | 8 – 13 | 二面角约 180°(Karplus)dihedral ≈180° (Karplus) |
| 邻位 ³J,环己烷 ax–eq / eq–eqVicinal ³J, ax–eq / eq–eq | 2 – 5 | 二面角约 60°dihedral ≈60° |
| 烯烃顺式 ³J(cis)Alkene ³J cis | 6 – 12 | 通常约 10typically ≈10 |
| 烯烃反式 ³J(trans)Alkene ³J trans | 12 – 18 | 通常约 16,用于区分 E/Ztypically ≈16; distinguishes E/Z |
| 端烯偕偶 ²J(=CH₂)Alkene geminal ²J (=CH₂) | 0 – 3 | |
| 烯丙位 ⁴JAllylic ⁴J | 0 – 3 | |
| 醛 ³J(CHO–CH)Aldehyde ³J (CHO–CH) | 1 – 3 | |
| 苯环邻位 ³J(ortho)Aromatic ortho ³J | 6 – 10 | 约 8≈8 |
| 苯环间位 ⁴J(meta)Aromatic meta ⁴J | 1 – 3 | |
| 苯环对位 ⁵J(para)Aromatic para ⁵J | 0 – 1 | 通常看不到usually unresolved |
| 炔丙位 ⁴J(≡C–H, CH)Propargylic ⁴J | 2 – 3 | |
| ¹J(¹³C–¹H),sp³ / sp² / sp¹J(¹³C–¹H), sp³ / sp² / sp | 125 / 160 / 250 | 约等于 500 × s 成分≈ 500 × s-character |
| ²J(H–C–F)Geminal ²J(H,F) | 45 – 50 | |
| ³J(H–C–C–F)Vicinal ³J(H,F) | 5 – 25 | |
| ¹J(¹³C–¹⁹F)¹J(¹³C,¹⁹F) | 160 – 350 | CF₃ 约 270CF₃ ≈ 270 |
| ³J(H–N–C–H),酰胺³J(HN–CαH), peptides | 4 – 10 | α 螺旋约 4,β 折叠约 9α-helix ≈4, β-sheet ≈9 |
n + 1 规律与帕斯卡三角n + 1 rule & Pascal’s triangle
一级谱中,与 n 个等价邻位质子偶合的质子裂分为 n + 1 重峰,强度比为二项式系数。若与两组不等价质子偶合(J 不同),则得到 dd、dt 等组合峰;Δν/J 小于约 10 时出现屋顶效应和二级谱。
In first-order spectra, coupling to n equivalent neighbours splits a signal into n + 1 lines with binomial intensities. Coupling to two inequivalent sets (different J) gives dd, dt, etc.; when Δν/J falls below ~10, roofing and second-order effects appear.
| 邻近等价 H 数 nEquivalent neighbours n | 峰形 Multiplet | 强度比 Intensity ratio |
|---|---|---|
| 0 | 单峰 s (singlet) | 1 |
| 1 | 二重峰 d (doublet) | 1 : 1 |
| 2 | 三重峰 t (triplet) | 1 : 2 : 1 |
| 3 | 四重峰 q (quartet) | 1 : 3 : 3 : 1 |
| 4 | 五重峰 quint (quintet) | 1 : 4 : 6 : 4 : 1 |
| 5 | 六重峰 sext (sextet) | 1 : 5 : 10 : 10 : 5 : 1 |
| 6 | 七重峰 sept (septet) | 1 : 6 : 15 : 20 : 15 : 6 : 1 |
氘代溶剂残留峰Residual solvent signals
氘代溶剂中的残留未氘代分子和水会出现在谱中;水峰位置随温度和氢键变化明显。¹H 峰形中 “quint” 指与 D(I = 1)偶合得到的 1:2:3:2:1 五重峰。
Residual protio solvent and water show up in spectra; the water signal moves with temperature and hydrogen bonding. A ¹H ‘quint’ is the 1:2:3:2:1 pattern from coupling to D (I = 1).
| 溶剂 Solvent | δH 残留residual | 峰形Pattern | δC | H₂O / HDO |
|---|---|---|---|---|
| CDCl₃ 氘代氯仿 | 7.26 | s | 77.16 | 1.56 |
| DMSO-d₆ 氘代二甲亚砜 | 2.50 | quint | 39.52 | 3.33 |
| CD₃OD 氘代甲醇 | 3.31 | quint | 49.00 | 4.87 |
| D₂O 重水 | 4.79 | s | — | 4.79 |
| Acetone-d₆ 氘代丙酮 | 2.05 | quint | 29.84, 206.26 | 2.84 |
| CD₃CN 氘代乙腈 | 1.94 | quint | 1.32, 118.26 | 2.13 |
| C₆D₆ 氘代苯 | 7.16 | s | 128.06 | 0.40 |
| CD₂Cl₂ 氘代二氯甲烷 | 5.32 | t | 53.84 | 1.52 |
| THF-d₈ 氘代四氢呋喃 | 3.58, 1.72 | m | 67.21, 25.31 | 2.46 |
| Toluene-d₈ 氘代甲苯 | 7.09, 7.01, 6.97, 2.08 | m / quint | 137.48, 128.87, 127.96, 125.13, 20.43 | 0.43 |
| Pyridine-d₅ 氘代吡啶 | 8.74, 7.58, 7.22 | br | 150.35, 135.91, 123.87 | 4.96 |
| DMF-d₇ 氘代 DMF | 8.03, 2.92, 2.75 | br / quint | 163.15, 34.89, 29.76 | 3.51 |
| TFA-d 氘代三氟乙酸 | 11.50 | s | 164.2, 116.6 | 11.5 |
常见 NMR 核Common NMR nuclei
| 核 Nucleus | 自旋 I | 天然丰度 %Abundance % | γ / 10⁷ rad T⁻¹ s⁻¹ | ν at 9.4 T / MHz | 参比 Reference |
|---|---|---|---|---|---|
| ¹H | 1/2 | 99.98 | 26.75 | 400.0 | TMS |
| ²H (D) | 1 | 0.0115 | 4.11 | 61.4 | TMS-d₁₂ |
| ¹³C | 1/2 | 1.07 | 6.73 | 100.6 | TMS |
| ¹⁵N | 1/2 | 0.37 | −2.71 | 40.5 | CH₃NO₂ / 液氨 |
| ¹⁹F | 1/2 | 100 | 25.18 | 376.5 | CFCl₃ |
| ³¹P | 1/2 | 100 | 10.84 | 161.9 | 85% H₃PO₄ |
| ²⁹Si | 1/2 | 4.69 | −5.32 | 79.5 | TMS |
| ¹¹B | 3/2 | 80.1 | 8.58 | 128.3 | BF₃·OEt₂ |
| ¹⁷O | 5/2 | 0.038 | −3.63 | 54.2 | H₂O |
| ¹⁹⁵Pt | 1/2 | 33.8 | 5.84 | 86.0 | Na₂PtCl₆ |