title: A new family of [Cu(II)Ln(III)M(V)] heterotrimetallic complexes (Ln = La, Gd, Tb; M = Mo, W): model systems to probe exchange interactions and single-molecule magnet properties.
abstract: Four isostructural trinuclear 3d-4f-4(5)d heterotrimetallic complexes, with the general formula [L(2)CuLn(H2O)5(μ-NC)M(CN)7], were obtained from the association of binuclear 3d-4f complexes and {M(V)(CN)8}(3-) metalloligands (M = Mo, Ln = La ; M = W, Ln = La ; M = Mo, Ln = Gd ; M = Mo; Ln = Tb , where H2L(2) = 1,2-ethanediylbis(2-iminomethylene-6-methoxy-phenol)). The metalloligand coordinates through a single-cyanido group at the apical position of the copper(ii) ion belonging to the {Cu(II)Ln(III)} binuclear complex. The analysis of the magnetic data for the La(iii) derivatives (compounds and ), in the 1.85-300 K temperature range, shows a weak ferromagnetic exchange interaction between Cu(II) and Mo(V)/W(V) ions across the cyanido bridge (JCuM/kB = 3.6(6) K; g = 2.23(5) for and JCuM/kB = 3.8(6) K, g = 2.21(5) for , with H = -2JCuMSCu·SM). These results were used to simulate the magnetic properties of compound , using the isotropic spin Hamiltonian H = -2JCuMoSCu·SMo - 2JCuGdSCu·SGd. The resulting magnetic interaction between Cu(II) and Gd(III) ions via the phenoxo-bridge was found to be weakly ferromagnetic (JCuGd/kB = +4.5(2) K with JCuMo/kB = +3.6(2) K, gGd = gCu = 2.00 and gMo = 1.98). The dc magnetic properties for compound also show a predominant ferromagnetic interaction, while the ac magnetic measurements indicate the presence of the slow relaxation of the magnetization below 3.5 K.
authors.affiliation: Coordination and Supramolecular Chemistry Laboratory, Institute of Physical Chemistry "Ilie Murgulescu", Romanian Academy, Splaiul Independentei 202, 060021 Bucharest, Romania.
authors.forename: Diana
authors.initials: D
authors.lastname: Visinescu
authors.affiliation: Inorganic Chemistry Laboratory, Faculty of Chemistry, University of Bucharest, Str. Dumbrava Rosie, nr. 23, 020464 Bucharest, Romania. marius.andruh@dnt.ro and Department of Inorganic Chemistry Physical Chemistry and Electrochemistry, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania.
authors.forename: Maria-Gabriela
authors.initials: MG
authors.lastname: Alexandru
authors.affiliation: Inorganic Chemistry Laboratory, Faculty of Chemistry, University of Bucharest, Str. Dumbrava Rosie, nr. 23, 020464 Bucharest, Romania. marius.andruh@dnt.ro.
authors.forename: Augustin M
authors.initials: AM
authors.lastname: Madalan
authors.affiliation: CNRS, CRPP, UPR 8641, F-33600 Pessac, France. clerac@crpp-bordeaux.cnrs.fr and Univ. Bordeaux, CRPP, UPR 8641, F-33600 Pessac, France and CNRS, ICMCB, UPR 9048, F-33600 Pessac, France and Univ. Bordeaux, CRPP, UPR 9048, F-33600 Pessac, France.
authors.forename: Ie-Rang
authors.initials: IeR
authors.lastname: Jeon
authors.affiliation: CNRS, ICMCB, UPR 9048, F-33600 Pessac, France and Univ. Bordeaux, CRPP, UPR 9048, F-33600 Pessac, France.
authors.forename: Corine
authors.initials: C
authors.lastname: Mathonière
authors.affiliation: CNRS, CRPP, UPR 8641, F-33600 Pessac, France. clerac@crpp-bordeaux.cnrs.fr and Univ. Bordeaux, CRPP, UPR 8641, F-33600 Pessac, France.
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Clérac
authors.affiliation: Inorganic Chemistry Laboratory, Faculty of Chemistry, University of Bucharest, Str. Dumbrava Rosie, nr. 23, 020464 Bucharest, Romania. marius.andruh@dnt.ro.
authors.forename: Marius
authors.initials: M
authors.lastname: Andruh