triplet state


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trip·let state

a second excited state of a molecule (for example, chlorophyll) produced by absorption of light to produce the singlet state, then loss of some energy (fluorescence) to achieve the longer-lasting triplet state The molecule may remain sufficiently long in the triplet state for a second activating light quantum to be effective in producing a "second triplet" state, at a still-higher level of excitation, hence reactivity. Alternatively, the molecule may lose the triplet state energy directly and return to the ground state.
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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 [25]:
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).