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发帖数: 4445 | 1 Man, it seems there are two issues here:
(1) Whether a molecule can absorb photon and have direct vibrational
transitions.
(2) If the above is true, whether the transition is in the IR spectral range
or not.
Your book answers the second one. On the first one, it depends on whether a
particular mode of vibration changes dipole moment or not. All polar
molecules are IR-active. But the reverse is not true since non-polar
molecules can have IR active modes, too.
In the NON-polar molecule CO2, th |
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