Microwave-induced delayed MIDP

Burland and Schmidt [190] performed microwave induced delayed phosphorescence (MIDP) experiments using a sample preparation with a benzene host crystal for both pyrazine and pyrimidine. With this technique they found that the relative radiative rates closely resembled the relative total rates for the different spin sublevels, indicating a high quantum yield and low non-radiative rate. The spin sub-level rates of pyrazine for Tr and rv were given as 284 and 6.3 ms, respectively, to be compared with the best response theory result of 282 and 12 ms. The z (out-of-plane) spin component is symmetry forbidden, and its lifetime (400 ms) derives from the lattice perturbation. 

Microwave-Induced Delayed Phosphorescence (MIDP) Method... 

ESR Electron spin resonance MIDP Microwave induced delayed phos-... 

TTie porphyrin ZnP in a crystalline n-octane matrix at 1.2 K was investigated by optically detected magnetic resonance (ODM) and microwave induced delayed phosphorescence (MIDP) . ... 

The assignment of the orbital symmetry of the phosphorescent triplet state of iV,A, A, jV -tetramethyl-p-phenylenediamine (TMPD) has been studied by microwave-induced delayed phosphorescence (MIDP) and the assignment of B2 for the orbital symmetry established. ... 

In the method of microwave-induced delayed phosphorescence (MIDP), the excitation is suddenly extinguished at t = 0. After a time interval, a microwave pulse or rapid passage is applied to induce transitions between T and T. The sudden change in the phosphorescence intensity is described by... 

Complementary to the method of microwave-recovery, the method of micro-wave-induced delayed phosphorescence (MIDP) is sometimes used for studying population kinetics. MIDP is particularly suited for two-level systems in which only one of the levels is radiative, whereas the other, dark level, is long-living. The microwave recovery is mostly applied when both levels are radiative. In the MIDP experiment the exciting light is chopped (or pulsed). In the dark time, after optical excitation, a resonant microwave pulse is applied at the delay time f(j. At t(j> the population still present in the non-radiative level is in part transferred to the radiative level. Thus a phosphorescence intensity change is induced, the amplitude of which is proportional to the population present in the non-radiative level, at time Measurement of the amplitude decay with gives the decay transient for the non-radiative level. The (fast) decay of the delayed phosphorescence transient at times t>t is typical of the decay of the radiative level. 

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