Luminescent characteristics of tetraphenylporphyrin and its derivatives with lutetium

The spectral and luminescent characteristics of new tetraphenylporphyrin derivatives that contain the lutetium atom in their structure are studied in comparison with the most completely studied unsubstituted tetraphenylporphyrin and its complex with zinc. The luminescence quantum yields in liquid and frozen solutions are measured. The specific features of luminescent characteristics of these compounds and their possible applications are discussed.     

Onium hexacyanoferrates(II) with some halogenated anilines

Onium hexacyanoferrates(II) with 3-and 4-chloroaniline and 4-bromoaniline are studied by X-ra powder diffraction and thermal analyses and IR spectroscopy. The compounds are formed due to the protonation of the amino groups. The thermal stability of the complexes depends on the nature of outer-sphere amines. The kinetic parameters for the first step of thermal destruction of the complexes are calculated.     

Spectral-kinetic characteristics of lutetium-containing tetrapyrroles

The spectral-kinetic characteristics of the triplet states of tetraphenylporphyrin and triphenylcorrole complexes with an aminopolycarboxylic acid (EDTA or DTPA) or its complex with lutetium as a substitute and the corrole complex with Ga(III) as the central atom have been studied. The transient absorption spectra of the complexes in the triplet excited state (effective maximum at 460–470 nm) and the rate constants of triplet quenching by oxygen at room temperature (2 × 10⁸–7 × 10⁸ L mol^?1 s^?1) have been measured. The quantum yields (0.44–0.55) and the molar absorption coefficients of the triplet state (log ?_T = 4.81–4.89) have been determined for some of the derivatives. The efficiency of population and deactivation kinetics of the triplet states are determined by the structure of the porphyrinoid, in particular by the central ion, and depends slightly on the presence of a heavy atom at the periphery of the molecule. Possible uses of the new compounds for designing various optical devices are discussed.     

Acid-base properties and phototransformations of complexone(ate)-substituted tetraphenylporphyrin

The spectral luminescent properties of series of tetraphenylporphyrin derivatives containing complexone-substituent in one of phenyl cycles or its complex with rare earth ion (Lu(III) or Gd(III)) are studied. The basicity of compounds in the ground and electronically excited states are investigated, and the quantum yields of phototransformations under pulsed radiation are measured. The relationship between the photochemical stability of the compounds and their acid-base properties is discussed.     

Luminescence of metal complexes of chelate-substituted tetraphenylporphyrin

The luminescence and absorption spectra of some metal complexes of new tetraphenylporphyrin derivatives containing a chelating group with a heavy atom in the ligand structure were studied and compared with the properties of the zinc complex of unsubstituted tetraphenylporphyrin. The quantum yields of fluorescence and phosphorescence of liquid and frozen solutions of these compounds were measured. The life-times of delayed emission have been estimated, and the nature of bands in the absorption and luminescence spectra of the complexes and their relation with the structure are discussed.     

Luminescence of the free bases of chelate-substituted tetraphenylporphyrin derivatives and their complexes with lutetium

The absorption and luminescence spectra of the free-base forms of some new tetrarphenylporphyrin derivatives bearing a chelating group or lutetium chelate as a substituent on the phenyl ring were studied with reference to the properties of unsubstituted tetrarphenylporphyrin. The fluorescence and phosphorescence quantum yields were measured for solutions of these compounds at various temperatures. The nature of the absorption and luminescence spectral bands of the complexes and their relation to the structure are discussed.     

Study of luminescence properties of cyclic and acyclic thiadiazole-containing compounds

Luminescence properties of thiadiazole-containing compounds of cyclic and acyclic structure have been investigated. All compounds are characterized by fluorescence in the region 500–600 nm. The highest quantum yield of luminescence in the studied series is exhibited by acyclic product of the ABA type (where A is thiadiazole cycle, B is isoindole cycle) with N-pentylthiadiazoline fragments.     

Kinetic Parameters of Thermal Destruction of 1,4-Phenylenediamine Hexacyanoferrate(II)

Thermal decomposition of 1,4-phenylenediamine hexacyanoferrate(II) in an inert atmosphere is studied. Kinetic parameters (reaction order, activation energy, pre-exponential factor) calculated by the Horowitz–Metzger, Coats-Redfern, and Lipskis methods are compared. Good convergence of the results and advantage of the Lipskis differential method are shown.