Lanthanide(III) Based Complexes Containing 5,7‐Dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidine as Long‐Lived Photoluminescent Antiparasitic Agents

Abstract

We report the synthesis and characterization of a new family of lanthanide‐based compounds containing a triazolopyrimidine derivative ligand, having the [Ln(H2O)9][Ln(NO3)6]·9dmtp {Ln = La (1) and Nd (2)} and [Ln(H2O)3(NO3)3]·3dmtp {Ln = Eu (3), Gd (4), Tb (5), Dy (6), Er (7) and Yb (8), where dmtp = dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidine} formulae. These materials possess variable structures and show variable luminescence properties, as well as interesting antiparasitic activities against pathogenic agent of Leishmaniasis and Chagas disease, which makes these compounds excellent candidates to be further investigated to develop new drugs against those neglected diseases. Moreover, the measurement of the photoluminescence properties of Eu‐ and Tb‐counterparts revealed that the dmtp ligand possesses accessible triplet states which can not only promote an efficient antenna effect that enhances lanthanide‐based emissions but also prolong them to several milliseconds.

Determination of Rare Earth Elements in Geological Samples by Inductively Coupled Plasma Mass Spectrometry

“…Rare earth elements include both the lanthanides (elements from lanthanum (La) to lutetium (Lu) with atomic numbers 57 -71 in the periodic table), plus scandium (21) and yttrium (39). They are typically divided in two groups, the light rare elements (LREE), from La to Eu, and the heavy rare earth elements (HREE), from Gd to Lu, this classification is based on their atomic mass and effective ion radius [19,20].…”

“…The rare earth also exhibit antibacterial, antifungal and nematicidal activities at levels comparable to copper ions, which are widely used as antibacterial metal [36][37][38][39]. In agriculture, REE are used in fertilizers.…”

Complexos imínicos de cobre com atividade antiparasitária frente à doença de chagas

“…O principal ponto de divergência frente a amostragem de resultados se deve ao tempo de incubação, com estudos utilizando 24h como tempo padrão, mas podendo variar até 72h. [43][44][45] O tempo de incubação pode ser muito impactante, principalmente para os ensaios que utilizam o MTT como ferramenta de medida, pois quanto maior o tempo de incubação, maior a probabilidade de a mortalidade apresentada ocorrer devido à escassez de nutriente no meio de cultura.…”