Spectral-luminescent effects in heterometallic complexes of crown-porphyrins

Abstract

New complexes of ytterbium with porphyrins containing crown-and other oxygen-containing cyclic substituents were obtained. The absorption, excitation, ligand luminescence and 4f-luminescence spectra have been investigated. It has been shown that 4f-luminescence of ytterbium Yb(III) ions was a result of the intramolecular energy transfer from the triplet level of the ligands to the resonance 2 F 5/2 level of Yb(III). It has been also established that in presence of alkali metal Na, K and Cs the dimer complexes (sandwich-type) of ytterbium-crown-porphyrin were formed. Molecular luminescence of the porphyrin matrix was quenched completely in these dimers, but at the same time the quantum yield and lifetime of 4f-luminescence increase in the complexes.

Reactivity of aqua coordinated monoporphyrinate lanthanide complexes: synthetic, structural and photoluminescent studies of lanthanide porphyrinate dimers

“…All the complexes exhibited NIR emission at 980 nm, which can be assigned to the 2 F 5/2 → 2 F 7/2 transition of Yb 3+ . [33][34][35] The NIR luminescence lifetime ranges from 1.02 to 3.17 ls and is much longer than the porphyrinate emission. The excitation spectra of these complexes are very similar to that of [Yb(TPP)(T P H )].…”

Synthesis of a Series of Heavy Lanthanide(III) Monoporphyrinato Complexes with Tetragonal Symmetry

“…In the beginning, these complexes were developed as a new NMR probe for use in biological systems. 2,3 The studies have further spread to new areas such as photoluminescence 4,5 and magnetism. 6 Generally, the lanthanide(III) monoporphyrinato complexes were prepared via an intermediate obtained from a reaction between free-base porphyrin and lanthanide acetylacetonate (acac) at high temperature.…”

“…Since the lanthanide­(III) monoporphyrinato complexes were reported in 1974, studies on the compounds have been carried out from various aspects. In the beginning, these complexes were developed as a new NMR probe for use in biological systems. , The studies have further spread to new areas such as photoluminescence , and magnetism …”

Lanthanide–tetrapyrrole complexes: synthesis, redox chemistry, photophysical properties, and photonic applications

“…Korovin et al prepared crown-porphyrins (Fig. 18) according to the Thanabal and Krishnan method, 110,111 which involves the reaction between a 4 0 -aldehyde crown ether and pyrrole in propionic acid under reflux conditions for 45 min. The work-up procedures were similar to TPP syntheses and the product was obtained after purification by column chromatography on basic alumina with chloroform-THF-MeOH as the eluent.…”