Question

What 4 considerations should one make on the first "pass" of an IR spectra?

Answer 1

On the first 'pass' of an IR spectrum, one should consider the identification of functional groups, the unique fingerprint region, bonding nature reflected in the spectra, and % transmittance to gauge the spectrum's information about molecular structure.

Step-by-step explanation:

When conducting the first "pass" of an IR spectra, there are four considerations to bear in mind:

1. Identifying the functional groups based on their characteristic absorption frequencies.
2. Examining the fingerprint region, which is unique to each molecule and helps to confirm the molecule's identity by comparing it to known standards.
3. Understanding the bonding nature reflected through the IR spectra, like the bond strength and the molecular vibrations, and observing the trends in wavelength and their relation to bond types (single, double, triple).
4. Noting the % transmittance and wavenumber values to gauge how strongly light was absorbed at each frequency, where 100% transmittance indicates no absorption.

Utilizing these considerations, the IR spectrum can provide valuable information about the molecular structure and confirm whether chemical reactions have proceeded as expected.