How do chemists determine the precise locations
of individual atoms within a molecule?
For atomic physics, the only thing we can observe
is spectra. Bombard the sample with radiation,
modulate the temperature, read the spectra. But
we can't micro-photograph and see the locations
of the components.
For instance, fatty acids:
https://tinyurl.com/fatty-acid00
--
Rich
How do chemists determine the precise locations
of individual atoms within a molecule?
For atomic physics, the only thing we can observe
is spectra. Bombard the sample with radiation,
modulate the temperature, read the spectra. But
we can't micro-photograph and see the locations
of the components.
For instance, fatty acids:
https://tinyurl.com/fatty-acid00
--
Rich
How do chemists determine the precise locations
of individual atoms within a molecule?
For atomic physics, the only thing we can observe
is spectra. Bombard the sample with radiation,
modulate the temperature, read the spectra. But
we can't micro-photograph and see the locations
of the components.
For instance, fatty acids:
https://tinyurl.com/fatty-acid00
Ian is correct that x-ray diffraction is one of the most satisfying techniques in terms of
getting structural information.
Even a simple proton NMR tells you a lot about how the atoms in a molecular are connected.
Add to that fancier NMR experiments that give you atom-to-atom distances like the nuclear
Overhauser effect, or experiments that give direct connectivity information like INADEQUATE
and suddenly a whole world of structural characterization opens up with the need to crystallize a compound.
Then there is mass spectroscopy. Because typical mass spec experiments break up molecules
into pieces, the masses of the pieces tell you something at least about local connectivity.
On October 3, M. Roussel wrote:
How do chemists determine the precise locations
of individual atoms within a molecule?
For atomic physics, the only thing we can observe
is spectra. Bombard the sample with radiation,
modulate the temperature, read the spectra. But
we can't micro-photograph and see the locations
of the components.
For instance, fatty acids:
https://tinyurl.com/fatty-acid00
Ian is correct that x-ray diffraction is one of the most satisfying techniques in terms ofThat's a special case, restricted to to crystals.
getting structural information.
Even a simple proton NMR tells you a lot about how the atoms in a molecular are connected.What is the output of the NMR, how does the chemist reconstruct the structure of the molecule?
Add to that fancier NMR experiments that give you atom-to-atom distances like the nuclear
Overhauser effect, or experiments that give direct connectivity information like INADEQUATE
and suddenly a whole world of structural characterization opens up with the need to crystallize a compound.
Are they solving Schrodinger's equation?
Then there is mass spectroscopy. Because typical mass spec experiments break up moleculesAgain, do they have mathematical models, using quantum mechanics?
into pieces, the masses of the pieces tell you something at least about local connectivity.
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