Influence of lanthanide ion energy levels on luminescence of corresponding metalloporphyrins

2017 ◽  
Vol 19 (11) ◽  
pp. 7728-7732 ◽  
Author(s):  
Huimin Zhao ◽  
Lixin Zang ◽  
Chengshan Guo

Energy transfer between the 4f energy levels of lanthanide ions and HMME determines whether lanthanide porphyrins can exhibit RTP.

2005 ◽  
Vol 14 (04) ◽  
pp. 555-564 ◽  
Author(s):  
HWAN KYU KIM ◽  
NAM SEOB BAEK ◽  
JAE BUEM OH ◽  
JAE-WON KA ◽  
SOO-GYUN ROH ◽  
...  

We have designed and developed novel lanthanide(III)-cored supramolecular systems with light-harvesting dendritic arrays for advanced photonics applications such as planar waveguide amplifiers, plastic lasers, and light-emitting diodes. The supramolecular ligands, such as naphthalenes and metalloporphyrins, were specially designed and synthesized in order to provide enough coordination sites to form stable lanthanide(III)-chelated complexes. The energy levels of the supramolecular ligands were tailored to maintain the effective energy transfer process from supramolecular ligands to lanthanide(III) ions for getting a higher optical amplification gain. Also, efficient energy transfer pathways for the sensitization of lanthanide ions by supramolecular ligands were investigated, for the first time to the best our knowledge. Furthermore, to enhance the optophysical properties of novel supramolecular systems, aryl ether-functionalized dendrons as photon antennas have been incorporated into lanthanide-cored supramolecular systems, yielding novel lanthanide-cored dendritic materials with efficient site-isolation effect.


2008 ◽  
Vol 8 (11) ◽  
pp. 5776-5780 ◽  
Author(s):  
C. Manikyala Rao ◽  
V. Sudarsan ◽  
R. S. Ningthoujam ◽  
U. K. Gautam ◽  
R. K. Vatsa ◽  
...  

ZnGa2O4 nanoparticles doped with lanthanide ions (Tb3+ and Eu3+) were prepared at a low temperature of 120 °C based on urea hydrolysis in ethylene glycol medium. X-ray diffraction studies have confirmed that strain associated with nanoparticles changes as Tb3+ gets incorporated in the ZnGa2O4 lattice. Based on steady state emission and excitation studies of ZnGa2O4:Tb nanoparticles, it has been inferred that ZnGa2O4 host is characterized by a broad emission around 427 nm and there exists energy transfer between the host and Tb3+ ions. Unlike this, for ZnGa2O4:Eu nanoparticles, very poor energy transfer between the host and Eu3+ ions is observed. These nanoparticles when coated with ligands like oleic acid results in their improved dispersion in organic solvents like chloroform and dichloromethane.


Author(s):  
Rajani A. Bhoyar ◽  
A. C. Nayak

Lanthanide ions are very efficient activators. Due to the presence of shielded 4f shell, the energy levels can be predicted with relative ease. Interaction with the surrounding lattice is minimum and luminescence efficiency is high. For this reason, many important phosphors having various applications have been discovered which use lanthanide activators. For obtaining efficient phosphors, it is important to find a suitable host for lanthanide activators which can accommodate these ions without concentration quenching. The hosts must be transparent to the emitted light. Lanthanides, most commonly occur as trivalent. Thus, hosts constituted by trivalent metals can be suitable. Yttrium compounds have been extensively studied as hosts. Scandium is another trivalent metal. Compared to the yttrium compounds, Scandium compounds have been very scarcely studied as hosts. We are investigating Scandium compounds as luminescence hosts. Synthesis and photoluminescence properties of Sr9 Sc (PO4)7 : Eu3+ and Sr8MgSc(PO4)7:Eu3+ phosphor are described in this work. The phosphors were prepared by solid state reaction. Usually, these phosphors are reduced and results on Eu2+ photoluminescence are reported. However, we have recorded photoluminescence before reduction and thus new results on Eu3+ emission could be obtained.


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