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Questions tagged [raman]

For questions relating to Raman scattering/effect and its applications as spectroscopy technique.

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Raman spectrum of acid acetic with deuterium?

I have raman spectrums of 3 differents acetic acid in solution : $$CH_3COOH \qquad \qquad CH_3COOD \qquad \qquad CD_3COOD$$ All the following are hypothesis from me and I would like to know if it's ...
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structure information form IR and Raman spectra? [closed]

Is it possible to gain the idea of full molecular structure from IR or Raman spectroscopy?
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Absence of anti-Stokes line in Raman spectrum

If we have a molecule 1H-25X which shows a band at $3000~\mathrm{cm}^{-1}$ in the IR spectrum and you want to record a Stokes and anti-Stokes Raman spectrum with a laser of 1000 nm, why is the anti-...
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What is the difference of polarizability and dipole moment? [duplicate]

One is for Raman and the other is for IR. The words both have 'pole', so I often confused each other.
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How on the quantum level do the notch filters used in Raman spectroscopy remove only a select wavelength of light?

From what I have gathered regarding the schematics of Raman spectrometers, the notch filter is used to remove a narrow range of light corresponding to that of the laser used to excite the sample. How ...
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Raman database of polymer spectra for analyses in R/python

Can anyone reccomend a raman database of polymer spectra that is open source or freely available? I'm analyzing spectra of a number of plastics and looking for reference spectra for identification. ...
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Scan type of DFT calculations adding Freq=Raman keyword [duplicate]

I´m doing a scan calculation by adding Freq=Raman keyword. My objective is to obtain the Raman spectrum of each conformation in my compound. However, when i write the Freq=Raman Keyword, only the ...
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2answers
157 views

How to obtain the Raman spectrum along every coordinate of a scan in Gaussian?

I am doing a scan calculation using Gaussian09 and adding the Freq=Raman keyword to my input file. My objective is to obtain the ...
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1answer
70 views

Raman activity in sulfur

I was wondering why sulfur is Raman active but other elements (e.g. carbon) are not.
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447 views

What drives the cost of Raman spectroscopy? [closed]

Raman spectroscopy setups are quite expensive- \$10-\$30k seems pretty common. The spectrometer, the probe/fiber cable, and the laser are typically each $3k+. The spectrometer could potentially be ...
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Isotopic Dioxygen Raman Spectroscopy

Comment on the fact that $\ce{^{16}O-^{18}O}$ dioxygen leads to only one v($\ce{O-O}$) Raman active stretching frequency at $\mathrm{728~cm^{-1}}$. Isotopic substitution will make the molecule ...
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1answer
140 views

Spectroscopy pyrazine molecule

Considering pyridazine and pyrazine molecules, I am asked to say if I can distinguish one from the other in a sample. I supposed that is possible because pyrazine belongs to D2h and so it has the ...
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663 views

Identification of Sir Raman's handheld scope

I read an article somewhere around 5-10 years ago that talked a little bit about the life of Sir C. V. Raman. The focus was on the effect of Raman spectroscopy but included an interesting little ...
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388 views

Raman Spectroscopy: How to calculate their constants?

$^1{\ce{H2}}$ is interrogated with a laser of wavelength lambda = 532 nm and vibrational Stokes transitions are observed at S(0) = 14302.206 cm$^{-1}$, Q(0) = 14638.442 and O(2) = 14992.823 cm$^{-1}$. ...
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429 views

Consider the vibrational mode that corresponds to the boat-like bending of a benzene ring. Is it (i) Infrared active? (ii) Raman active?

This question was asked in an assignment in my college. So we've been taught how to distinguish functional groups by IR and nothing much. So I request someone to please explain the answer in detail.
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1answer
275 views

Raman Spectrum of carbon chains: How to identify the vibrational modes

So I am using NWChem to calculate the raman spectra of C2H2 and C4H4. For example for the first I obtained the following frequencies: ...
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1answer
382 views

Compound formed from concentrated sulfuric acid and sulfur

In the reaction below, I know what A and B are, but I'm not sure what compound C is. All I know about it is the following: Deep yellow solid Dication contains only sulfur Raman and infra-red spectra ...
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1answer
583 views

Why hydrofluoric acid (HF) has two Raman bands?

Hydrofluoric acid ($\ce{HF}$) is a diatomic molecule with only one vibrational coordinate. Therefore I would expect only one Raman band, however there are two. Why? (source)
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Raman Spectra of Toluene

This is the raman spectra of Toluene I obtained while working at my lab using a raman spectrometer with laser of 532 nm wavelength. Well, I am a physics student, but I want to know how information ...
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SERS Gold nanoparticles performing poorly in organic solvents?

We have been working with some organic solvents lately and noticed a sharp decrease in surface-enhanced Raman spectroscopy (SERS) performance from our gold nanoparticles deposited in an organic ...
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1answer
798 views

Calculating Raman Intensities from Static Raman Activities

Whenever I want to calculate a Raman spectrum, my quantum chemical programs give me Raman scattering activities. As the common Raman spectrum is dependent on the incident wavelength of the used laser ...
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97 views

What are the strategies to deal with fluorescence from oil in Raman Spectroscopy?

I have a sample (for the purpose of this question let's call this Sample A) consisting of oil (edible olive oil) mixed with a contaminant (Contaminant B) from the Polycyclic Aromatic Hydrocarbons ...
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2answers
320 views

Why does Stokes raman not relax to the ground state while anti-Stokes does?

I'm just wondering why stoke-Raman doesn't go to the ground state. Where does the rest of energy from exciting laser leave? On the other hand, why does anti-stoke go back to ground state? I know that ...
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1answer
574 views

Role of Acetonitrile and Ammonium Acetate buffer in Leucomalachite Green stock solution?

I am trying to repeat an experiment conducted by FDA on Malachite Green (MG). According to this paper, ...
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1answer
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Which are the differences between resonance Raman and fluorescence?

If the fluorescence is the re-emitting of a photon with a larger wavelenght due to the transition from a higher energy state to a lower energy state the case of resonance Raman (where there aren't any ...