CHEM 261 Lecture Notes - Lecture 37: Infrared Spectroscopy, Tetramethylsilane, Chemical Shift
7 Jan 2017
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Chem261 lecture 37 nmr and peak splitting. Chemical analysis: can give you molecular information, in a timely manner, and with a small amount (sample, these are the different methods, mass spectroscopy. What happens in nmr: sample in magnetic field alignment, irradiated with em, radiation at right frequency spin-flip (resonance): e absorbed, frequency for resonance depends on magnetic field strength and identify of nuclei. Chemical shifts: to find a chemical shift, use the equation below, there are two types of hydrogens in this case below. Deshielding effects: more electronegativity means more deshielding, deshielding effects decrease with distance. Peak splitting: non-equivalent h"s on adjacent carbons will split one another (due to contributions or opposition to magnetic fields. Peak splitting: triplets (two adjacent protons: when both hbs are aligned with the magnetic field, ha will be deshielded will be aligned with the field and the other hb against.
