While analyzing the UV spectra of my compound, I got data for the UV transitions where I go the Lamda max and excitation energy but I could not find the oscillator strength. Whereas I recorded the sample in UV spectrum I got the oscillator strength but not the excitation energy. If there possibility of finding the values of oscillator strength from excitation energy.
To compute the oscillator strength, f, you need to know epsilon max (the molar absorption coefficient at lambda max) and the width of the absorption band (in energy units, e.g. cm-1), see any Physical Chemistry textbook. But there is a good correlation between epsilon max and f, so if you just want a qualitative measure of the strength of the transition epsilon max is enough: 10,000 - 100,000 M- cm-1 means an allowed transition (f roughly between 0.1 and 1), whereas epsilon max below 10 M-1 cm-1 means a «forbidden» transition (which does not mean it cannot be observed: all depends on absorbance, hence also on concentration and path length - the blue color of copper sulfate aqueous solutions, for instance, is quite familiar).
The oscillator strength can be calculated from absorption measurements. Oscillator strength related to the molar decadic absorption coefficient by the following equation
f=4.32x10-9 x integrating molar decadic abs.coff. over the wavenumber regions
Where ε is molar decadic absorption coefficient carrying the unit L mol-1 cm-1 and wave
number ν in cm-1.The calculated results using this technique quite similar with the theoretical calculation. see the attached lit.
mr Ugandare
first of all please note that the question is from the year 2014
I remember a good description in the textbook of Kautzmann
but also here
https://books.google.nl/books?id=NC5uUlqhQCYC&pg=PA167&lpg=PA167&dq=kautzmann+quantum+chemistry&source=bl&ots=4Vjms0wzuP&sig=ACfU3U2JOieMBC2Cs55h0vshpUj6lGlTOg&hl=nl&sa=X&ved=2ahUKEwif4ZOlsvblAhWIaVAKHcrqCS4Q6AEwAHoECAkQAQ#v=onepage&q=kautzmann%20quantum%20chemistry&f=false
textbook of Turro et al. pg 196
Dear Rasheed Ogundare
The oscillator strength can be calculated from absorption measurements. Oscillator strength related to the molar decadic absorption coefficient by the following equation
f=4.32x10-9 x integrating molar decadic abs.coff. over the wavenumber regions
Where ε is molar decadic absorption coefficient carrying the unit L mol-1 cm-1 and wave
number ν in cm-1.The calculated results using this technique quite similar with the theoretical calculation. see the attached lit
I humbly suggest to refer this video to find oscillator strength using Origin 2019 software
https://youtu.be/s72zuKo2iyM
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