| Texto completo | |
| Autor(es): |
Dezotti, Yuri
;
Vaz, Raphael Capruni Andrade
;
Ribeiro, Marcos Antonio
;
Passamani, Edson Caetano
;
de Almeida, Adriele Aparecida
;
Knobel, Marcelo
;
Ardisson, Jose Domingos
;
Barros, Wdeson Pereira
Número total de Autores: 8
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Crystal Growth & Design; v. 24, n. 9, p. 11-pg., 2024-02-16. |
| Resumo | |
The synthesis and structural, magnetic, and hyperfine properties of a new metal-organic framework are presented. Its chemical formula is [Fe-6(pvb)(4)(HCOO)(6)(OH)(2)](n)<middle dot>2n(dmf)<middle dot>2n(H2O) (1), where pvb(-) = bis{4-[2-(4-pyridyl)vinyl]} benzoate. Compound 1 was obtained under hydro(solvo)thermal conditions, presenting a hexanuclear iron(II) motif, which extends through HCOO- and pvb(-) bridges, resulting in a 2D framework linked covalently to adjacent analogous layers by the pvb(-) ligands to form a 3D coordination polymer. 300 and 80 K Fe-57 M & ouml;ssbauer data suggested two paramagnetic iron(II) species in the extended structure of compound 1, presenting a distorted octahedral high-spin state. Alternating current magnetization data recorded in zero and in-field showed two well-defined ordering temperatures at ca. 13 and 2.5 K for the two iron(II) species in less and highly distorted octahedral symmetry, respectively. The system undergoes magnetic transition from a paramagnetic state at high temperatures to a magnetically ordered state at 13 K. At 2.5 K, the ordered spins present a canted-like structure. These magnetic states are field dependent, showing a metamagnetic phase transition for fields higher than 5 kOe. A remnant magnetization of 1.91 N beta and a coercive field, H-C, of 10 kOe are obtained at 2 K, indicating a hard magnetic state often found when AF and FM exchange interactions are present. (AU) | |
| Processo FAPESP: | 20/09280-0 - Estudo das propriedades magnéticas, luminescentes, foto-reativas e redox de sistemas moleculares polinucleares contendo íons metálicos de transição e lantanídeos |
| Beneficiário: | Wdeson Pereira Barros |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |