However, an opposite effect is expected, since that [S.sub.1] and [T.sub.2], the adjacent triplet state
, are both of the same orbital symmetry.
Clearly, more loss channels are present that reduce the efficiency, and now, triplet state
formation plays a role in the charge loss in these materials.
One common method of photoactivation is via energy transfer from the longer-lived triplet state
of the photosensitizer to the substrate [37-39].
In Type-II reaction, the excited- state molecule reacts directly with 3O2 to generate highly toxic triplet state
oxygen (1O2) [1, 3].
The triplet state
quantum yield was determined by the power dependent comparative method :
In the neutral structure of tetraoxygen with [D.sub.2h] point group and triplet state
are more stable than singlet state and other structures.
Since orthohelium is trapped in the excited triplet state
, it has an opportunity to once again react with hydrogen, as displayed in the lower portion of Fig.
The phosphorescence spectra of ketones with an n-[pi]* nature of the lowest triplet state
are usually structured due to the vibrational progression of the C=0 vibration, and [pi]-[pi]* triplets are mostly unstructured.
The result of excitation is that the sensitizer moves from an electronic ground state to a triplet state
that then interacts with microbial components to generate cytotoxic species.
The radiative and non radiative relaxation of the triplet state
are represented by [k.sub.T] and [k.sub.d] respectively.
In phosphorescence, absorbed photon energy crosses into a higher energy state, called a triplet state
. Energy becomes trapped, being released far slower than with fluorescence because of quantum mechanical conditions.
When considering the excited triplet state
energies of both ITX and maleic anhydride derivatives (64 and 72 kcal/mol, respectively), photosensitization is highly unlikely since an energy transfer fronot m a lower energy to a higher energy is not thermodynamically favored (2).