Lecture 6 Outline of Last Lecture I Beginning of Chapter 13 NMR Outline of Current Lecture II Continuation of Chapter 13 a Spin Spin Split b Multiplets c Coupling Constants Current Lecture Spin Spin Split Number of Hydrogens on a molecule Number of Hydrogens on a neighboring atom within the molecule Reciprocal Properties if one proton splits another the second splits first Multiplets Doublet Recognizable as two peaks on an NMR The first peak shows a hydrogen in line going with with the magnetic field The second peak shows a hydrogen against the magnetic field Triplet Peak ratios are affected by the spins Equivalent carbon atoms require the same environment protons bonded to the same carbon will split each other if NOT equivalent Quartet 1 3 3 1 ratio N 1 4 therefore N 3 which shows the molecule is next to 3 protons These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Steps for analyzing quartets BPM Integration Splitting The number of signals number of different types of hydrogens There is no splitting with 4 or more bonds between hydrogens the distance from one hydrogen to another in a molecule Coupling Constants Used in determination of the distance between peaks of a multiplet in Hertz Deals only with hydrogens not substituants Independent of external magnetic fields May come from adjacent groups of protons if values are equal A true Multiplet has identical distances When dealing with multiple coupling constants a splitting tree is used method of stacking Splitting Tree Example 2