SPIN. Elektron. Proton

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Szymon Karpiński
7 lat temu
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1 SPIN Elektron Proton

2 SPIN - SPIN

3 MULTIPLETOWOĄÖ H H H H H Cl Multipletowość = 2*I (spin jądra) + 1

4 Relative intensity of split peaks Pascal's triangle: Singlet 1 Doublet 11 triplet 121 quartet 1331 quintet sextet Septet

6 STAôA SPRZâģENIA

PRZESUNIâCIE CHEMICZNE δ = (przesunięcie w Hz) / (Częstotliwość aparatu Hz) * 1000000 Natężenie pola: B 0 = 1.

7 PRZESUNIâCIE CHEMICZNE δ = (przesunięcie w Hz) / (Częstotliwość aparatu Hz) * Natężenie pola: B 0 = 1.41 Tesla B 0 = 2.35 Tesla Częstotliwość aparatu: 60 MHz 100 MHz Przesunięcie wzgędem TMS: 162 Hz 270 Hz : 2.70 ppm 2.70 ppm

8 EKRANOWANIE CH 3 X CH 3 H CH 3 I CH 3 Br CH 3 Cl CH 3 F Element X H I Br Cl F Elektronegatywność

9 MAGNETIC ANISOTROPY EFFECTS Protons attached to the aromatic ring "feel" a larger magnetic field than protons elsewhere in the molecule. Aromatic ring protons will therefore resonate at higher frequency and exhibit a downfield shift (7-8 ppm). Acetylenic hydrogen is shielded by this induced field, and will therefore resonate at lower frequency (2-3 pmm).

10 PRZESUNIâCIE CHEMICZNE

11 MULTIPLETOWOĄÖ H H H H H Cl Multipletowość = 2*I (spin jądra) + 1

12 Multipletowość

13 Sprzężenie w układzie aromatycznym

14 Sprzężenie w układzie aromatycznym

15 Bromek allilu

16 Efekt dachowy

17 INKREMENTY PODSTAWNIKÓW H H Y X δ = 0,23 + Z X + Z Y R H Y X δ = 0,23 + Z X + Z Y + Z R X-CH 2 -Y Podstawnik Inkrement -R C=C C,C triple bond C 6 H NR NHC(O)R NO SR C(O)R C(O)C 6 H OH OR OC(O)R OC 6 H F Cl Br I CO 2 R C(O)NR CN 1.70

18 INKREMENTY PODSTAWNIKÓW R (cis) H R (trans) R(gem) sp 2 hybrydyzacja zwiększa s- charakter atomów węgla a więc elektronegatywność. (4.5-7 ppm ) δ = 5,25 + Z gem + Z cis + Z trans

19 INKREMENTY PODSTAWNIKÓW H R (ortho) R (meta) R (para) δ = 7,36 +Z ortho + Z meta + Z para

20 SPEKTROSKOPIA 13 C Only the less abundant 13C nucleus (1.08% natural abundance) can undergo nuclear spin flip. Therefore, the signal produced is very small, and acquisition of a spectrum takes quite a bit longer. The magnetogyric ratio of the 13C nucleus is smaller than that of the hydrogen nucleus, causing the resonance frequency for 13C NMR to be much lower than in 1H NMR spectroscopy (15.1 MHz for 13C as opposed to 60 MHz for 1H in a 1.41 Tesla field). At these lower frequencies, the excess population of nuclei in the lower spin state is reduced, which, in turn, reduces the sensitivity of NMR detection procedures.

22 PRZESUNIâCIE CHEMICZNE

23 PRZESUNIâCIA CHEMICZNE DLA C=O

24 SP 3 13 C PRZESUNIâCIA C ω -C δ -C y -C b -C a -C-C a -C b -C y -C δ -C ω δc = a b -2.5 y δ ω + Σ a (steric corrections) ppm Observed Carbon Atom Steric Corrections (ppm) Type of Attached Carbon Primary Secondary Tertiary Quaternary Primary Secondary Tertiary Quaternary C 1 = (1) + 9.4(3) - 2.5(1) + [1(-3.4)] = 29.1 ppm Obserwowano: 29.1 ppm CH 3 4 CH 3 2 C = (4) + 9.4(1) + [3(-1.5) + 1(-8.4)] Obserwowano: = 30.6 ppm 30.6 ppm H 3 C C CH CH C = (2) + 9.4(3) + [1(-7.5)] Obserwowano: 4 C = (1) + 9.4(1) - 2.5(3) + [1(0.0)] = 36.6 ppm 36.9 ppm = 8.7 ppm Obserwowano: 8.9 ppm

SP 3 13 C PRZESUNIâCIA δc = δc 0 + Σ (increments) ppm terminal: internal: Substituent Y a b g a b g -CH3 9 10-2 6 8-2 -CH=CH2 20 6-0.5-0.5 -CCH 4.5 5.4-3.5-3.

25 SP 3 13 C PRZESUNIâCIA δc = δc 0 + Σ (increments) ppm terminal: internal: Substituent Y a b g a b g -CH CH=CH CCH C6H CHO C(O)CH CO2H CO2R C(O)NH CN NH NHR NR NO OH OR OC(O)CH F Cl Br I

26 SP 2 13 C PRZESUNIâCIA C y -C b -C a -C 1 =C 2 -C a' -C b' -C y' δc 1 = [ 10.6 a b -1.5 y ] - [ 7.9 a' b' -1.5 y' ] + Σ(steric corrections) ppm Steric Corrections (ppm) Ca and a' are trans (E-configuration) 0 Ca and a' are cis (Z-configuration) -1.1 Two alkyl substituents at C1 (two Ca) -4.8 Two alkyl substituents at C2 (two Ca') 2.5 Two or more alkyl substituents at Cb) 2.3 H 3 C H C C H 3 C 1 2 CH 3 1 C = [10.6(2)] - [7.9(1)] + [(-4.8) + (-1.1)] Observed: 2 C = [10.6(1)] - [7.9(2)] + [(2.5) + (-1.1)] Observed: = ppm ppm = ppm ppm

27 SP2 13C PRZESUNIâCIA δc = δc0 + Σ (increments) ppm

28 AROMATYCZNE 13 C PRZESUNIâCIA δc = Σ i Substituent δ-ipso δ-ortho δ-m eta δ-para -M e E t npr ipr tb u C H =C H C CH C 6H C H 2C l C H 2O H C H O C (O ) R C (O )C6H C O 2H C O 2R C N N H N R N H C (O )R N O O H O CH O C(O )R F C l

29 WIDMO SPRZâģONE Z PROTONEM

30 NOE (NUCLEAR OVERHAUSER EFFECT ) The NOE effect is quite general; it occurs whenever two dissimilar atoms are irradiated simultaneously. In the proton- decoupled experiment, the carbon-13 nuclei are observed at the same time that the hydrogen nuclei are irradiated. The hydrogen nuclei are irradiated, the number of nuclei in the higher energy "spin-opposed" state is increased. The carbon atoms to which these protons are attached adjust their equilibrium distribution to increase the population of carbon atoms in the lower energy "spin-aligned" state due to the interaction of spin dipoles. This larger population of carbon atoms in the lower spin state results in a larger number of nuclei that can be detected, and therefore an increased signal. Not all carbon-13 signals will be enhanced to the same extent. Generally, the larger the number of attached protons the larger the enhancement will be.

31 DECOUPLING

32 HOMOTOPIC, ENANTIOTOPIC, AND DIASTEREOTOPIC SYSTEMS Homotopic protons are those that, when substituted for by deuterium, lead to the same structure. Homotopic protons are always equivalent, and will give one signal in the NMR Enantiotopic protons are those that, when substituted for by deuterium, lead to a pair of enantiomeric structures. Enantiotopic protons appear to be equivalent (and will usually give one signal in the NMR), but can be made nonequivalent by placing the molecule in a chiral environment (chiral resolving reagent). Diastereotopic protons are those that, when substituted for by deuterium, lead to a pair of diastereomeric structures. Diastereotopic protons are not equivalent and will usually give different signals in the NMR.

33 NH2, OH H 3 C O OH H 3 C O OH :39:59 Probka Ol._TADDOL w chloroformie 1H Acquisition Time (sec) Comment Probka Ol._TADDOL w chloroformie 1H Date 23 Oct :46:08 Date Stamp 23 Oct :46:08 File Name D:\WIDMA\COMPOUNDS\OL_TADDOL ALDRICH\OL_TADDOL ALDRICH_125000FID Frequency (MHz) Nucleus 1H Number of Transients 4 Origin spect Original Points Count Owner root Points Count Pulse Sequence zg30 Receiver Gain SW(cyclical) (Hz) Solvent CHLOROFORM-d Spectrum Offset (Hz) Sweep Width (Hz) Temperature (degree C) OL_TADDOL ALDRICH_125000FID VerticalScaleFactor = Normalized Intensity Chemical Shift (ppm)

34 NH 2, OH Me-OH

35 ROZPUSZCZALNIKI DO NMR Solvent δ (ppm) acetic acid - d 4 acetone - d 6 acetonitrile - d 3 benzene - d 6 carbon tetrachloride chloroform - d dimethylsulfoxide - d (singlet), 11.7(singlet) 2.09 (singlet) 1.93 (singlet) 7.15 (singlet) none 7.25 (singlet) 2.49 (singlet) ethanol - d , 3.56, 5.19 methanol - d 4 methylene chloride - d 2 water - d (singlet), 4.78 (singlet) 5.32 (singlet) 4.82 (singlet)

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