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Lecture 18b, Molecular frequency response 


Many examples of spectra of molecules are presented on the
following pages. The spectra can be used to identify the
presents of specific molecules. Note that the same chemical
designation may result in more than one molecular structure
and the resulting spectra may be different.

Basic physics:
c = velocity of light = about 300,000,000 meters per second
f = frequency in Hz, Kilo KHz = 1000 Hz, Mega Mhz = 106Hz
                     Giga GHz = 109Hz Tera THz = 1012Hz
λ = wavelength in meters, μ = 10-6 meters = 1000 nano meters

  c = λ * f
  λ = c / f
  f = c / λ

Example: wavelength  1 μ has frequency, f, computed by
f =  300*106 / 10-6 = 300*1012Hz = 300 THz


The "visible" spectrum, that which can be seen by average people,
is roughly given by wavelength in nm = nanometer or 10-9



The following pages show the spectrum of many molecules.

The Infrared spectrum has wavelength μ in micrometers, 10-6 meters

The notation Frequency, cm-1 must be multiplied by 30*106
to get Hz.

The Nmr, Nuclear magnetic resonance, data is in Nmr units and Hz.

molecular.pdf Molecular frequency response 


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