Raman Spectroscopy: ?????????????? ????????? ? ?????? ????????? ?????

1
Raman Spectroscopy ?????????????? ????????? ?
?????? ????????? ?????
???????? ??????? 204-? ?????? ??????? ????????.
???? ?????? ??? ???????? ?? ?????? ???
????? ??????????? ????????? ? ??? ????????
?????????? ???????? ? ??? ??????? ? ??????
2
Raman Spectroscopy ?????
????????????? ????????????? ???????????????
???????? ??????? ?? ???????? ????? - Minimal
sample preparation (gas, liquid, solid) -
Compatible with wet samples and normal ambient
- Achilles Heal is sample fluorescence
3
Raman Spectroscopy ?????
IR ? ??????????? ????? ??????? ??? ?????????
?????????? ?? ?????????
?????, ??? ????? Raman, ? ??? - IR
4
Raman Spectroscopy ?????
??????????? ????????????? ???????
5
Raman Spectroscopy ???????????? ?????????
?????????? ????? ?? ??????? ??????? DoF 3N
- 6 (bent) or 3N - 5 (linear) for N atoms
??????? ?????????????? ??????????? ???????
????????? Rule of thumb symmetricRaman active,
asymmetricIR active
CO2
H2O
Raman 1335 cm1
Raman IR 3657 cm1
IR 2349 cm1
Raman IR 3756 cm1
IR 667 cm1
Raman IR 1594 cm1
6
??????? ?????????? ???????? ??????????,
?????????, and ?????????????
2nd Electronic Excited State
25,000
Impurity
1st Electronic Excited State
Elastic Scattering (Raleigh)
Excitation Energy, s (cm1)
fluorescence
semit
s
s
semit
semit
fluorescence
4,000
Vib. states
Electronic Ground State
s
0
IR
UV/Vis Fluorescence
7
???????????
2nd Electronic Excited State
25,000
1st Electronic Excited State
Stokes
Anti-Stokes
Excitation Energy, s (cm1)
s
semit
4,000
Vib. states
Electronic Ground State
s
?s
?s
Raman ?ssemits
Resonance Raman ?ssemits
0
IR s
8
?????????????? ????????? At NTUF, ???????????
?? ??????
Near IR 785 nm
Visible 514 nm
Intensity
Stokes
Anti-Stokes
Stokes
Anti-Stokes
?s
?s
?s
?s
11,000
13,000
15,000
17,000
19,000
21,000
Excitation Energy, s (cm1)
9
???????????? ? ??????????????
10
Raman Spectroscopy ?????

• ??????????? ????????? ??????? ?????????????
  ??????? ?????? IR
• - ??????? ??? ?????????????, ????????????
  ???????????? ??????
• ???????? ?? ?????????, ? ?? ?? ???????? ???
  ?????????
• ?? ??????? ????????? ?????????? ?? ?? ????????,
  ?? ?? ????, ?? ?? ??.????
• ?????? ?????????? ????-???????? ?????????? ??-??
  ????????????
• ????? ??????? ??????? ???????????
• 785 nm ????????????? ????? ????????, ??????
  ?????.
• 514 nm????????????? ????? ????????, ????? ?????.

11
??????? ?? ????????!!!!