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Type:	Artigo de Periódico
Title:	Heterobimetallic one-dimensional coordination polymers MICuII (M = Li and K) based on ferromagnetically coupled Di- and tetracopper(II) metallacyclophanes
Authors:	Tamyris Teixeira da Cunha Willian Xerxes Coelho Oliveira Emerson Fernandes Pedroso Francesc Lloret Miguel Julve Cynthia Lopes Martins Pereira
Abstract:	The synthesis, crystal structure and magnetic properties of the coordination polymers of formula [EDAP{Li6(H2O)8[(Cu2(μ-mpba)2)2(H2O)2]}]n (1) and [(EDAP)2{K(H2O)4[Cu2(μ-mpba)2(H2O)2]}Cl·2H2O]n (2), in which mpba = N,N′-1,3-phenylenebis(oxamate) and EDAP²+ = 1,1′-ethylenebis(4-aminopyridinium) are described. Both compounds have in common the presence of the [Cu2(mpba)2]4− tetraanionic unit which is a [3,3] metallacyclophane motif in which the copper(II) ions are five-coordinate in a distorted square pyramidal surrounding. The complex anion in 1 is dimerized through double out-of-plane copper to outer carboxylate-oxygen atoms resulting in the centrosymmetric tetracopper(II) fragment [Cu4(μ-mpba)4(H2O)2]8− which act as a ligand toward six hydrated lithium(I) cations leading to anionic ladder-like double chains whose charge is neutralized by the EDAP²+ cations. In the case of 2, each dicopper(II) entity acts as a ligand towards tetraquapotassium(I) units to afford anionic zig zag single chains of formula {K(H2O)4[Cu2(μ-mpba)2(H2O)2]}n³n− plus EDAP²+ cations and non-coordinate chloride anions. Cryomagnetic measurements on polycrystalline samples 1 and 2 show the occurrence of ferromagnetic interactions between the copper(II) ions across the –Namidate–(C–C–C)phenyl–Namidate– exchange pathway [J = +10.6 (1) and +8.22 cm−¹ (2)] and antiferromagnetic ones through the double out-of-plane carboxylate-oxygen atoms [j = −0.68 cm−¹ (1), the spin Hamiltonian being defined as H=−J(SCu1⋅SCu2+SCu2i⋅SCu1i)−j(SCu2⋅SCu2i)].
Subject:	Magnetoquímica Cristalografia Propriedades magnéticas Materiais magnéticos
language:	eng
metadata.dc.publisher.country:	Brasil
Publisher:	Universidade Federal de Minas Gerais
Publisher Initials:	UFMG
metadata.dc.publisher.department:	ICX - DEPARTAMENTO DE QUÍMICA
Rights:	Acesso Aberto
metadata.dc.identifier.doi:	https://doi.org/10.3390/magnetochemistry4030038
URI:	http://hdl.handle.net/1843/49116
Issue Date:	2018
metadata.dc.url.externa:	https://www.mdpi.com/2312-7481/4/3/38
metadata.dc.relation.ispartof:	Magnetochemistry
Appears in Collections:	Artigo de Periódico

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