Substituent effects on novel lanthanide(III) hydrazides complexes

Autor(es)

Brandao, Samira G. ^[1] ; Ribeiro, Marcos A. ^[1] ; Perrella, V, Rafael ; de Sousa Filho, Paulo C. ^[2] ; Luz, Priscilla P. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Espirito Santo, Dept Chem, BR-29075910 Vitoria, ES - Brazil

^[2] Perrella, Rafael, V, Univ Estadual Campinas, Inst Chem, POB 6154, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF RARE EARTHS; v. 38, n. 6, p. 642-648, JUN 2020.
• Citações Web of Science: 0

Resumo

New lanthanide (Eu3+ and Gd3+) complexes were successfully synthesized and the effect of the p-phenyl substituent on the Eu3+ luminescent properties was evaluated. In this sense, benzhydrazide, p-toluic hydrazide, 4-hydroxybenzhydrazide and 4-aminobenzoic hydrazide were used as ligands and the complexes were obtained by mixing the lanthanide salts with hydrazides in ethanol at room temperature and keeping the reaction for 2 h under mechanical stirring. Crystal of Gd-amino was obtained and its structure was elucidated by single-crystal X-ray diffraction, revealing that Gd3+ centered in a distorted tricapped trigonal-prismatic molecular geometry. IR spectroscopy and the elucidated structure confirm hydrazides acting as bidentate ligands binding to Ln(3+) ions through the oxygen of carbonyl group and the nitrogen of terminal amine, forming a five-membered ring. CHN analyses confirm the molecular formulas {[}Gd(amino)(4)(H2O)](NO3)(3)center dot(C2H2OH) and {[}Eu(toluic)(3)(H2O)](NO3)(3). Lower T-1 state energies are observed for ligands p-substituted with higher electron donating capacity groups, such as p-NH2 and p-OH. In contrast, higher lifetimes and quantum efficiencies are obtained for Eu3+ complexes with ligands p-H and p-CH3 substituted, which are not deactivator groups. (C) 2019 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 17/11764-2 - Estratégias na síntese de nanomateriais luminescentes para o desenvolvimento de novos sensores ópticos multimodais
• Beneficiário: Paulo Cesar de Sousa Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular