Novel Co<sub>5</sub> and Ni<sub>4</sub> Metal Complexes and Ferromagnets by the Combination of 2-Pyridyl Oximes with Polycarboxylic Ligands
Foteini Dimakopoulou,
Costantinos G. Efthymiou,
Ciaran O’Malley,
Andreas Kourtellaris,
Eleni Moushi,
Anastasios Tasiopooulos,
Spyros P. Perlepes,
Patrick McArdle,
Ernesto Costa-Villén,
Julia Mayans,
Constantina Papatriantafyllopoulou
Affiliations
Foteini Dimakopoulou
School of Biological and Chemical Sciences, College of Science and Engineering, National University of Ireland Galway, University Road, H91 TK33 Galway, Ireland
Costantinos G. Efthymiou
School of Biological and Chemical Sciences, College of Science and Engineering, National University of Ireland Galway, University Road, H91 TK33 Galway, Ireland
Ciaran O’Malley
School of Biological and Chemical Sciences, College of Science and Engineering, National University of Ireland Galway, University Road, H91 TK33 Galway, Ireland
Andreas Kourtellaris
Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus
Eleni Moushi
Department of Life Sciences, European University of Cyprus, Nicosia 2404, Cyprus
Anastasios Tasiopooulos
Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus
Spyros P. Perlepes
Department of Chemistry, University of Patras, 26504 Patras, Greece
Patrick McArdle
School of Biological and Chemical Sciences, College of Science and Engineering, National University of Ireland Galway, University Road, H91 TK33 Galway, Ireland
Ernesto Costa-Villén
Departament de Química Inorgànica i Orgànica, Secció Inorgànica and Institute of Nanoscience (IN2UB) and Nanotecnology, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
Julia Mayans
Departament de Química Inorgànica i Orgànica, Secció Inorgànica and Institute of Nanoscience (IN2UB) and Nanotecnology, Universitat de Barcelona, Marti i Franques 1-11, 08028 Barcelona, Spain
Constantina Papatriantafyllopoulou
School of Biological and Chemical Sciences, College of Science and Engineering, National University of Ireland Galway, University Road, H91 TK33 Galway, Ireland
The use of 2-pyridyl oximes in metal complexes chemistry has been extensively investigated in the last few decades as a fruitful source of species with interesting magnetic properties. In this work, the initial combination of pyridine-2-amidoxime (pyaoxH2) and 2-methyl pyridyl ketoxime (mpkoH) with isonicotinic acid (HINA) and 3,5-pyrazole dicarboxylic acid (H3pdc) has provided access to three new compounds, [Ni4(INA)2(pyaox)2(pyaoxH)2(DMF)2] (1), [Co5(mpko)6(mpkoH)2(OMe)2(H2O)](ClO4)6 (2), and [Co5(OH)(Hpdc)5(H2pdc)] (3). 1 displays a square-planar metal topology, being the first example that bears simultaneously HINA and pyaoxH2 in their neutral or ionic form. The neighbouring Ni4 units in 1 are held together through strong intermolecular hydrogen bonding interactions, forming a three-dimensional supramolecular framework. 2 and 3 are mixed-valent Co4IIICoII and Co2IIICoII3 compounds with a bowtie and trigonal bipyramidal metal topology, accordingly. Direct current and alternate current magnetic susceptibility studies revealed that the exchange interactions between the NiII ions in 1 are ferromagnetic (J = 1.79(4) cm−1), while 2 exhibits weak AC signals in the presence of a magnetic field. The syntheses, crystal structures, and magnetic properties of 1–3 are discussed in detail.
