radiationless transition मीनिंग इन हिंदी

Intersystem Crossing ( ISC ) is a photophysical process involving an isoenergetic radiationless transition between two electronic states having different multiplicities.
The observation of electron tracks that were independent of the frequency of the incident photon suggested a mechanism for electron ionization that was caused from an internal conversion of energy from a radiationless transition.
However the El-Sayed s rule states that the rate of intersystem crossing, e . g . from the lowest singlet state to the triplet manifold, is relatively large if the radiationless transition involves a change of molecular orbital type.
Radiationless transition between levels, such as between the excited " S " = 0 and " S " = 1 states, may proceed quickly enough to siphon off a portion of the " S " = 0 population before it spontaneously returns to the ground state.