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Spectroscopy & IR Spectroscopy in Structure Determination
What is Spectroscopy?
Spectroscopy is a scientific technique that involves the study of the interaction between matter and electromagnetic radiation. It is used to analyze the structure, composition, and properties of substances based on how they absorb, emit, or reflect light at specific wavelengths.
This method is critical in fields such as chemistry, physics, and biology for identifying unknown compounds and understanding molecular behavior.
How IR Spectroscopy Helps in Structure Determination
Infrared (IR) Spectroscopy is a type of spectroscopy that measures how molecules absorb infrared light, causing vibrations in chemical bonds. Different bonds absorb IR radiation at characteristic frequencies, producing a spectrum that acts like a molecular “fingerprint.”
- Functional Group Identification: IR spectroscopy reveals the presence of functional groups such as hydroxyl (-OH), carbonyl (C=O), amine (-NH), etc., based on their unique absorption bands.
- Molecular Structure Clues: The shape and number of peaks in an IR spectrum can indicate bond types and molecular geometry.
- Purity Check: IR spectra can detect impurities or confirm the identity of a compound by comparing it to reference spectra.
Example: A strong absorption near 1700 cm−1 typically indicates the presence of a carbonyl group (C=O), helping chemists determine if the compound contains aldehydes, ketones, or carboxylic acids.