A mononuclear complex and a cubane cluster from the initial use of 2-(hydroxymethyl)pyridine in nickel(II) carboxylate chemistry |
| |
| Authors: | Constantinos G Efthymiou Constantina Papatriantafyllopoulou Nadia I Alexopoulou Catherine P Raptopoulou Roman Bo?a Jerzy Mrozinski Evangelos G Bakalbassis Spyros P Perlepes |
| |
| Institution: | 1. Department of Chemistry, University of Patras, 26504 Patras, Greece;2. Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA;3. Institute of Materials Science, NCSR “Demokritos”, 15310 Agia Paraskevi Attikis, Athens, Greece;4. Department of Inorganic Chemistry, Slovak Technical University, 81237 Bratislava, Slovakia;5. Institute of Chemistry, University of Wroclaw, 14 F. Joliot-Curie, 50383 Wroclaw, Poland;6. Laboratory of Applied Quantum Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece |
| |
| Abstract: | The reactions of 2-(hydromethyl)pyridine, hmpH, with Ni(O2CMe)2·4H2O in H2O, in the absence of counterions, have been investigated. The synthetic study has led to the two new complexes Ni(O2CMe)2(hmpH)2] (1) and Ni4(O2CMe)4(hmp)4(H2O)2] (2). Complex 1 can also be transformed into 2 by reacting with an excess of NaOH in H2O. The structures of 1 and 2·2.25H2O·0.5(1,4-dioxane) have been solved by single-crystal, X-ray crystallography. The octahedral NiII center in centrosymmetric 1 is coordinated by two 1.10 (Harris notation) MeCO2− groups and two N,O-chelating (1.11) hpmH ligands. The tetranuclear cluster molecule of 2·2.25H2O·0.5(1,4-dioxane) possesses a distorted cubane {Ni4(μ3-OR′)4}4+ core R′ = (2-pyridyl)CH2–] with the NiII ions and the oxygen atoms from the 3.31 hmp− ligands occupying alternate vertices of the cube. Two 2.11 MeCO2− groups cap two opposite faces of the cube, while two 1.10 MeCO2− ions and two aqua ligands complete the octahedral coordination sphere of the metal centers. Characteristic IR bands for the two complexes are discussed in terms of the nature of bonding and the structures of the two complexes. The variable-temperature magnetic properties of 2 have been modeled with two J values, and reveal antiferromagnetic exchange interactions between the four NiII ions to give a diamagnetic ground state. |
| |
| Keywords: | Acetate ligands Crystal structures 2-(Hydroxymethyl)pyridine metal complexes Magnetic properties Nickel(II) cubane clusters |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
