This document discusses proton nuclear magnetic resonance (1H NMR) spectroscopy. It explains that 1H NMR provides information about the type, number, and environment of hydrogen atoms in a compound. The principle is based on radio wave absorption by nuclei in an organic molecule placed in a strong magnetic field. Specifically, it describes the phenomenon of nuclear magnetic resonance, where hydrogen nuclei align parallel or anti-parallel to the external magnetic field and absorb energy to flip orientations. The spectrum is displayed on a chemical shift scale and shows signals corresponding to unique sets of protons. Factors like electronegativity, bonds, temperature, and solvent affect the chemical shift values.

1. SPEKTROMETRI PROTON NMR
OLEH :
YUSBARINA, M.Si
JURUSAN P. KIMIA FTK UIN SUSKA RIAU

2. NMR ?
NUCLEAR MAGNETIC RESONANCE
ATAU
RESONANSI MAGNET INTI
H-NMR C-NMR

3. Kegunaan H-NMR?
Memberikan gambaran mengenai :
1. Jenis hidrogen
2. Jumlah hidrogen
3. Lingkungan hidrogen dalam
suatu senyawa

4. Prinsip dasar H-NMR?
NMR didasarkan pada penyerapan
gelombang radio oleh inti – inti
tertentu dalam molekul organik,
apabila molekul tersebut berada dalam
medan magnet yang kuat

5. Fenomena Resonansi Magnetik Inti
Model fisika klasik:
Inti atom bermuatan positif dan berputar pada porosnya
(spin)
⇒ membentuk medan magnet yang berputar
⇒ penempatan di dalam suatu medan magnet (Bo)
menghasilkan putaran presesi yang menyerap di daerah
gelombang radio
⇒ frekuensi presesi dinyatakan oleh:

7. Proses terjadinya resonansi?

8. When molecules containing hydrogen atoms are
placed in an external magnetic field ; the
magnetic moment of each proton nucleus
aligns itself in one of two different
orientations:

9. • The parallel protons absorb energy (radio
waves) and the magnetic moment turn
around (flip) to the high energy antiparallel
state (Resonance)

10. 2 Cara agar terjadi resonansi?
Bo tetap,
frekuensi radiasi
elektromagnetik
diubah - ubah
frekuensi radiasi
elektromagnetik
tetap, Bo diubah –
ubah sampai
dicapai resonansi,
Lebih memuaskan

11. Bentuk spektrum NMR?

12. –The spectrum is measured on a delta ( ) scale in units
of parts per million (ppm)
–Lower frequency is to the left in the spectrum; these
absorptions are said to be downfield
–Higher frequency is to the right in the spectrum:
these absorptions are said to be upfield
–The small signal at 0 corresponds to an internal
standard called tetramethylsilane (TMS) used to
calibrate the chemical shift scale
–The number of signals in the spectrum corresponds
to the number of unique sets of protons

13. Pergesaran Kimia?
Perbandingan antara letak resonansi
suatu proton tertentu dengan letak
resonansi proton standar

14. • Chemical Shift
• Chemical shifts are measured in relation to the
internal reference tetramethylsilane (TMS)
– The protons of TMS are highly shielded because of the
strong electron donating capability of silicon
• The scale for chemical shifts is independent of
the magnetic field strength of the instrument
(whereas the absolute frequency depends on field
strength)

15. Ada apa dengan
TMS?
1. TMS mempunyai dua belas proton yang setara
kimia,karenya memberikan satu puncak tunggal
2. TMS merupakan cairan yang volatil, dapat ditambahkan
dalam jumlah sedikit pada larutan sampel dalam
pelarutnya, sampel dapat diperoleh kembali dengan
menguapkan pelarutnya
3. Proton pada hampir semua senyawa organik mengalami
resonansi pada medan yang lebih rendah daripada proton
TMS
4. TMS bersifat inert dan tidak larut dalam air

16. Faktor yang mempengaruhi
pergesaran kimia?

17. Faktor intramolekular
1. Efek induksi
2. Efek anisotropi
3. Efek mesomeri
Faktor intermolekuler
1. Ikatan hidrogen
2. Temperatur
3. Pelarut

18. Fields induced by sigma bonds
• The induced field from circulating sigma bond
electrons opposes Ho in the vicinity of proton

19. • A proton that is bonded to the same carbon as an
electronegative atom is more deshielded than proton
on other carbons. (Inductive Effect)
• H3C-F H3C-ClH3C-Br H3C-I
Increased shielding of H
C F
H
H
H
F causes a decrease in
e density around each atom

20. The inductive effect
C
H
H
H
C
H
H
C
H
H
X effect of X is important
in decreasing e density
around this proton
effect of X is of
little importance
in decreasing
e density around
this proton
Si
CH3
CH3
CH3
CH3
greater e density on H:
highly shielded
Tetramethylsilane(TMS)

21. Summary of induced field effects

22. Equivalent and nonequivalent protons
MENGHITUNG PROTON

23. CH3CH2OCH2CH3
six equivalent protons
four equivalent protons

24. C
CH3
CH3
H
Br six equivalent protons
CH3
CH3
CH3 Br six equivalent protonstwo

25. Spin-spin coupling
• Protons that split each other signals are said
to have undergone spin-spin coupling

26. n+1 Rule
• The number of peaks of a particular proton is
equal to number (n) of nonequivalent protons
on the adjacent atoms + 1

28. Notice:

29. Splitting pattern:
• The singlet
If no neighboring nonequivalent protons present 
one single peak (singlet) (S).
eg.
CH3 Cl CH3OCCH3
O
CCH3
CH3
Br
CH3 H
H
H
H
H
H

30. The doublet
• If one neighboring nonequivalent proton present 
two peaks (doublet) (d).
eg
CH3 C
H
Cl
Cl CH3 C
H
Cl
CH3
OCH3
HH
CH3
H H
C C
HH
Cl
Cl Cl
Cl
equivalent H's => S

31. The triplet
• If two neighboring nonequivalent protons present 
three peaks (triplet) (t).
eg
CH3CH2Cl
C C
HH
Cl
Cl Cl
H
ClCH2CH2OCH3

32. The quartet
• If a proton is neighboring to CH3  it will observe
3+1=4 peaks (quartet) (q)
eg
CH3CH2Cl CH3CHCl2
CH3CH2OCH2CH3