University:
York University
Course:
CHEM 1000 | Chemical Structure
Academic year:

2021
Views:

292

Pages:

2
Author:

Niklas

Lecture 9 (02/09/21) 14.1: Intro to Spectroscopy Spectroscopy involves an interaction between matter & light (electromagnetic radiation) Light waves ↔ E or packets (particles) E. → "Photons" Wavelength (λ): inversely proportional to E. Frequency (f): directly proportional to E. Electromagnetic Spectrum: Range of possible f of light. Textual Content: 14.2: IR Spectroscopy Molecular Bonds (MB) can vibrate by Stretching or Bending in diff. ways: Stretching In-plane Bending Out-of-plane Bending E. necessary to cause vibration depends on type of bond: C-H bond C-O bond Bigger the Mass Difference (AMU) - more E. req. to vibrate the bond. E (Larger gap) E (smaller gap) IR spectrophotometer irradiates a sample w/ all freq. of IR light. Looks by the sample tell us the Types of B. (FG) that are present. IR Abs. Spectrum: plots % transmittance as a function of freq. Peaks = Absorption Bands Look @ Position, Shape, & Signal (Peak) Characteristics: Wavenumber Intensity Shape X-Y: Similar Mass Units of Freq = Wavenumbers (cm⁻¹)