Spectroscopy

IR Spectroscopy: Some Simple Practice Problems

November 29, 2016

By itself, Infrared (IR) spectroscopy isn’t a great technique for solving the structure of an unknown molecule. However, we’ve seen that IR spectroscopy can a great technique for identifying certain functi…

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Infrared Spectroscopy: A Quick Primer On Interpreting Spectra

Infrared Spectroscopy: A Quick Primer On Interpreting Spectra

November 23, 2016

How To Interpret IR Spectra In 1 Minute Or Less: The 2 Most Important Things To Look For [Tongue and Sword] Last post, we briefly introduced the concept of bond vibrations, and we saw that we can think of covalent b…

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Bond Vibrations, IR Spectroscopy, and the “Ball and Spring” Model

Bond Vibrations, IR Spectroscopy, and the “Ball and Spring” Model

November 11, 2016

In This Post  Why do UV spectra have such broad peaks? The “stadium” analogy. Introduction to vibrational energy levels. Visualizing different vibrational energy levels A useful analogy: the “ball a…

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UV-Vis Spectroscopy: Some Practice Questions

UV-Vis Spectroscopy: Some Practice Questions

September 27, 2016

In the past few posts we’ve covered some of the key points of UV-Vis spectroscopy. Now comes the key question: how do we apply it? How can it be useful to us, especially in determining the structure of unknown c…

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UV-Vis Spectroscopy: Absorbance of Carbonyls

UV-Vis Spectroscopy: Absorbance of Carbonyls

September 26, 2016

In our last post we showed that molecules with C-C pi (π) bonds absorb light in the UV-visible region, which promotes electrons from (bonding) π orbitals to (anti bonding) π* orbitals. We saw that the energy requ…

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Introduction To UV-Vis Spectroscopy

September 16, 2016

In today’s post we’ll discuss why most molecules are colourless, introduce the useful technique of UV-visible spectroscopy, and finally explain why molecules like chlorophyll and β-carotene are coloured.…

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How Bleach Works: Understanding Colors From Nature

September 8, 2016

Why are tomatoes red? Why are carrots orange? Why are egg yolks yellow?   And… why is Vulcan blood green? OK, I’m not going to touch that last one, but as for the first three: great question. There are…

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Degrees of Unsaturation (Index of Hydrogen Deficiency)

August 26, 2016

The molecular formula of a compound can give helpful hints about its structure. Today we’ll talk about a quick and useful calculation we can perform to obtain the number of [multiple bonds + rings] in an un…

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Pictorial Guide to Infrared Spectra

Pictorial Guide to Infrared Spectra

August 3, 2011

From the “I wish I made this” department…. Pictorial Guide to Infrared Spectra (Jon Chui, U. of Victoria, Canada) Apparently Jon has been thinking about putting together a similar graphic for NMR, b…

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