Spectroscopy Essay

Asha Kurup
April 3rd, 2014

IR Spectroscopy Assignment

A. What is spectroscopy and how does it work?
Spectroscopy is a term for analyzing spectra. The spectra may be visible light, infrared, ultraviolet, X-ray, and other types1. When a beam of light hits a triangular prism, it is separated into its components (ROYGBIV).

Figure 1: Components of Light

Spectroscopy is measured using a spectrophotometer. A beam of light is first pointed towards the spectrophotometer. The beam of light then strikes a part of the spectrophotometer called the diffraction grating. The diffraction grating works similar to the prism shown above. It separates the light into its component wavelengths by rotating so that only a specific wavelength will reach a part of the spectrophotometer called the exit slit. On the other end of the exit slit there is a sample located in a test tube as well as a detector. After the wavelength passes through the sample, the detector measures the transmittance and absorption of the sample. The transmittance is the amount of light that was able to pass through the sample and reach the detector, and the absorption is the amount of light that was absorbed by the sample. The detector converts the measure of transmittance into s digital display, such as a graph.

B. What purpose does it serve in the industry?
Spectroscopy can help identify elements and compounds and elucidate the atomic and molecular structure by measuring the radiant energy absorbed or emitted by a substance at characteristic wavelengths of the electromagnetic spectrum on excitation by an external energy source. UV-Vis Spectroscopy is a technique useful for identification of organic and inorganic species and can be used for identification (qualitiative ana...

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...either sp3 hybridization or an alkyl group. By looking at the chemical structure, we can see that two methyl groups are present, and this peak confirms this.
There are no peaks in zone 3, therefore there are no alkyl or nitrile groups present. There are also no peaks in zone 4, indicating that there are no ketone, ester, or carboxylic acid functional groups present.
In zone 5, there are two peaks. One peak is at 1600cm-1, and the other is between 1500 and 1450cm-1. These two peaks indicate that a benzene ring is present in the chemical structure of the compound.
The next part of the graph is the fingerprint region. In the fingerprint region there are two important peaks. The first of these appears around 750cm-1, and the second at 690cm-1. These two peaks indicate that the benzene ring that we discovered present in the structure is a monosubstituted benzene ring.