CHE 202 1nd Edition Lecture 5 Outline of Last Lecture I Introduction to Nuclear Magnetic Resonance a Spin States II Magnetic Shielding III NMR Spectra a Analyzing Steps b Chemical Shif Outline of Current Lecture I Spin Splitting II Splitting Types a Doublet b Triplet c Quartet III Coupling Constants Current Lecture Spin Splitting Reveals the hydrogens on the molecule as well as the number of neighboring adjacent hydrogens Hydrogens with or against the external magnetic field causes the split Reciprocal relationship If one proton splits another the second proton splits the first Equivalent Carbons in order to be equivalent carbons must maintain the same environment surrounded by identical substituants an or hydrogens Long Range coupling The distance between hydrogens affects the splitting pattern if a hydrogen is four or more bonds away no splitting between these two hydrogens occurs Splitting Types Doublet o One peak represents a hydrogen in line with the electromagnetic field the other line represents a hydrogen against the electromagnetic field Triplet 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 o The spins affect the peaks ratios o Equivalent Carbons will not split each other Quartet o 1 3 3 1 Ratio o N 1 4 therefore N 3 therefore next to 3 protons Coupling Constants Distance between peaks of a multiplet in Hertz Deals only with hydrogens NOT substituants Independent of external magnetic field A true multiplet has identical distances between protons Determines the distances between hydrogens in Hz Splitting Tree is used when dealing with multiple coupling constants keep stacking couplets until one Example Splitting Pattern Splitting Tree