Heterometallic tetranuclear 3d–4f complexes: Syntheses, structures and magnetic properties

• Four tetranuclear 3d–4f complexes based on 4-trifluoromethylbenzoic acid have been synthesized and characterized.
• They adopt distinct coordination modes and various supramolecular frameworks.
• Complexes 1 and 3 exhibit slow magnetic relaxation processes, suggesting SMM type behavior.

Four novel heterometallic tetranuclear 3d–4f complexes M2Dy2L10(phen)2 (M = Co (1), Ni (2), Cu (3) and Zn (4); HL = 4-trifluoromethylbenzoic acid, phen = phenanthroline) have been synthesized hydrothermally and characterized by single crystal X-ray diffraction study, IR, elemental analysis and thermal gravimetric analyses. The structures of 1 and 4 are isostructural and the completely deprotonated L ligands adopt μ2: η1, η1 coordination mode to bridge adjacent metal ions which further connect into 1D chains by hydrogen bonds. The tetranuclears in complex 2 were linked by L ligands with μ2: η1, η2 and μ2: η1, η1 coordinated patterns and spread into 2D layers through hydrogen bonds. In complex 3 L ligands possess the same coordinated styles with 2 and a 3D supramolecular network was fabricated via hydrogen-bonding interactions. Dynamic magnetic susceptibility studies reveal slow magnetic relaxation processes for 1 and 3, suggesting SMM type behavior for these compounds.

Four tetranuclear 3d–4f complexes based on 4-trifluoromethylbenzoic acid and 1,10-phenanthroline (phen) have been synthesized and characterized. They adopt distinct coordination modes and various supramolecular frameworks. Complexes 1 and 3 exhibit slow magnetic relaxation processes, suggesting SMM type behavior.Figure optionsDownload as PowerPoint slide