Intraligand fluorescence and phosphorescence of tris(pyrazolyl) hydridoborate complexes

Sol–gel synthesis, paramagnetism, photoluminescence and optical properties of Gd-doped and Bi–Gd-codoped hybrid organo-silica glasses

“…The identification of these IL states should be facilitated by the absence of other low-energy excited states. Thus, several Gd(III) chelates are characterized by a room temperature phosphorescence which extends from the UV to the red spectral region depending on the ligands [52][53][54]. Similar effects were found by others [33].…”

“…ions neither should show fluorescence nor should be the source of phosphorescence in the visible and near infrared (NIR) regions [33]. This is certainly because neither metalcentered f-f transitions nor CT (MLCT or LMCT) occur at such low energies [33,[52][53][54]. Owing to the small absorption coefficients of Ln 3?…”

Splitting of alkyl carbonates photocatalyzed by copper complexes as a model for an artificial photosynthesis

“…We suggest that in agreement with the excited state properties of Tp complexes in general [11,12] the photoexcitation of Cu I Tp* leads to the population of an IL excited state followed by electron transfer to the carbonate. A radical anion is thus formed as an intermediate which is subsequently reduced by a second Cu I Tp* complex forming CO.…”

Interpretation of europium(III) spectra

“…The energy levels of the Gd 3+ ion are well above those of the triplet level so that no gadolinium(III)-centered emission is observed. Moreover, the heavy paramagnetic Gd 3+ ion enhances the intersystem crossing from the singlet to the triplet state, because of mixing of the triplet and singlet states ("heavy atom effect" and "paramagnetic effect") [352][353][354][355][356]. The triplet state acquires partially a singlet character by the spin-orbit coupling interaction, and the selection rules are relaxed.…”