TOPIC 9. STRUCTURE DETERMINATION (chapter 9 and part of chapter 2) Lect Topics Reading L29 COMBUSTION ANALYSIS EMPIRICAL AND MOLECULAR FORMULAS; DETERMINATION OF “SODAR” MASS SPECTROMETRY Theory and Experiment Data Available 9.13 An Introduction to Mass Spectrometry 9.14 Formation of Ions: Electron Impact Ionization 9.15 Depicting the Molecular Ion 9.16 Fragmentation 9.17 Determination of Molecular Formulas and Molecular Weights 9.18 Mass Spectrometer Instrument Designs 9.19 GC/MS Analysis 9.20 Mass Spectrometry of Biomolecules (8th ed.: Sections 9.12-18) L30 SPECTROSCOPY: THE INTERACTION OF LIGHT AND MATTER 9.1 Introduction INFRARED SPECTROSCOPY Molecular Vibrations: Stretching and Bending Electromagnetic Radiation Instrumentation and Spectrum Selected Infrared Absorptions 2.16 Infrared Spectroscopy L31 HYDROGEN (PROTON) NUCLEAR MAGNETIC RESONANCE (1H NMR) SPECTROSCOPY Nuclear Spin (1H, 13C, 19F, 31P) The Energy of the Spin States of Hydrogen Nuclei in a Magnetic Field Preview: Types of Information available from a 1H NMR spectrum (a) The number of signals in the spectrum is the number of types of proton 9.2 (8th ed.: 9.3) Nuclear Magnetic Resonance Spectroscopy 9.3 (not in 8th ed.) Interpreting Proton NMR Spectra 9.4 Nuclear Spin: The Origin of the Signal 9.5 (covered elsewhere in 8th ed.) Detecting the Signal: Fourier Transform NMR spectrometers L32 (b) The relative area of each peak (the integration) corresponds to the relative number of each type of proton (c) The chemical shift indicates the environment of the proton 9.6 (8th ed.: 9.5) Shielding and Deshielding of Protons 9.7 (8th ed.: 9.6) The Chemical Shift ContinuedL33 (d) The multiplicity of a signal indicates the number of adjacent protons Summary: Types of information available from 1H NMR spectrum 9.9 (8th ed.: 9.8) Signal Splitting: Spin – Spin Coupling L34 13C NMR SPECTROMETRY Introduction Types of Information available from a 13C NMR spectrum 4.19 (not in 8th ed.) 13C NMR spectroscopy – A Practical Introduction 9.11 (8th ed.: 9.10) Carbon-13 NMR Spectroscopy rev USING DATA TO DETERMINE STRUCTURE NOT COVERED: 9.10 (8th ed.: 9.9) Proton NMR Spectra and Rate Processes; 9.12(8th ed.: 9.11) Two-Dimensional (2D) NMR