CHM 228 -- FINAL

CHM 228 -- FINAL - CHAPTER 13 Infrared Spectroscopy (IR)...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
CHAPTER 13 – Infrared Spectroscopy (IR) H 13.1 – Electromagnetic Radiation (501) Low-Energy Light High Energy Light Low Frequency High Frequency Long Wavelength Short Wavelength 3 13.2 – Interaction of Electromagnetic Radiation with Molecules (502) 3 13.3 – The Electromagnetic Spectrum (503) 3 13.4 – Infrared Spectroscopy (505) 3 13.5 – Generalizations (507) Because of their larger force constants, stronger bonds absorb at higher wavenumbers than weaker bonds. For similar reasons, bond stretches absorb at higher wavenumbers than bends Bonds involving a light hydrogen atom have smaller reduced masses and therefore absorb at higher wavenumbers than bonds involving only heavier atoms. 3 13.6 –The Hydrogen Region (508) 3 13.7 – The Triple-Bond Region (515) 3 13.8 – The Double-Bond Region (518) 3 13.9 – The Fingerprint Region (520) 3 13.10 – Interpretation of IR Spectra (521) Position Group Comments Position Group Comments 3550-3200 O H Strong intensity, broad 1740 R C O O R' 3400-3250 N H 1730 R C O H 3300 C H 1715 R C O R' 3100-3000 C H 1710 R C O OH
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
3000-2850 C H 1690-1630 R C O NH 2 2830-2700 C O H Two Bands 1660-1640 C C Often weak intensity 2260-2200 C N Medium intensity 1600-1450 Four bands of variable intensity 2150-2100 C C Weak intensity N O O Two strong bands R C O O C O R 1300-1000 C O 1800 R C O Cl 900-675 CHAPTER 14 – Nuclear Magnetic Resonance Spectroscopy (NMR) H 14.1 – Proton Magnetic Resonance Spectroscopy (543) Chemical shift - provides information about the carbon (or another atom) to which the hydrogen is attached Multiplicity – the number of peaks in each group, provides information about the other hydrogens that are near the hydrogen or hydrogens that produce peaks (n+1) Integral – the area under a group of peaks is proportional to the number of hydrogens that produce the group of peaks 3 14.2 – Theory of 1 H-NMR (545) 3 14.3 – The Chemical Shift (547) Effects on Chemical Shift Inductive – increasing electronegativeity of atoms deshield nerby hydrogens, resulting in a downfield shift Pi Electron – there is a “ring current effect” that results in a large downfield shift for hydrogens attached to aromatic rings. Hydrogens bonded to Heteroatoms Approximate Chrmical Shifts of Hydrogens in 1 H-NMR Spectra Type of Hydrogen Chemical Shift Type of Hydrogen Chemical Shift Type of Hydrogen Chemical Shift C C H 3 0.9 N C H 3 2.2 C O O C H 3 3.7 C C C H 3 1.6 I C H 3 2.2 O 2 N C H 3 4.1 C C C H 3 1.8 N C C H 3 2.2 F C H 3 4.2 N H 1-3 C H 3 2.3 C C H 5.5-6.5 O H 2-5 Br C H 3 2.7 H 7-8 R O C C H 3 O 2.0 Cl C H 3 3.0 O C H 10 O C C H 3 2.2 O C H 3 3.3 C O O H 12
Background image of page 2
14. 4 – Spin Coupling (556) 3 14. 5 – Complex Coupling (562) 3 14.6 – Chemical Exchange (563) 3 14.7 – Deuterium (563) 3 14.8 – Interpretation of 1 H-NMR Spectra (566) Examine the general positions of the peaks Examine the integral for the ratios of the different kinds of hydrogens
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 11

CHM 228 -- FINAL - CHAPTER 13 Infrared Spectroscopy (IR)...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online