| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1340292 | Polyhedron | 2006 | 7 Pages |
A new tetranuclear copper(II) complex [Cu4L2(3-ppz)2] (1) has been prepared from the reaction of [Cu2LBr] and 3-phenylpyrazole (3-ppz), where H3L is a pentadentate Schiff base N,N′-(2-hydroxypropane-1,3-diyl)bis(salicylaldimine). The complex as 1 · 6H2O has been structurally characterized by X-ray crystallography. The structure shows the presence of a tetranuclear copper(II) complex with a core showing Cu⋯Cu distances in the range of 3.261(1)–3.492(1) Å. The tetrameric complex is formed from the self-assembly of two dimeric {Cu2L}+ units in the presence of two anionic 3-ppz ligands as linkers. The alkoxo oxygen atoms bind three copper(II) centers giving two equatorial and one axially elongated Cu–O bond. The variable temperature magnetic susceptibility data in the range 300–17 K show antiferromagnetic spin–spin coupling giving magnetic moments of 3.3 μB at 300 K and 0.56 μB at 17 K for the Cu4 unit. A theoretical fitting to the magnetic data gives J values of −86.3, −47.32 and 11.13 cm−1 with a diamagnetic ground state. The crystal structure shows the presence of two complexes and 12 water molecules in the unit cell belonging to the triclinic space group P1¯. Among them, 10 water molecules form an aggregate in which six water molecules are in a chair conformation of the cyclohexane-type with two water dimers hydrogen bonded to the cyclic structure. The discrete decameric water assembly is anchored onto the metalloorganic host involving four phenoxo oxygen atoms of two Cu4 units and four water molecules of the cyclic chair hexameric unit through hydrogen bonding interactions.
Graphical abstractAn antiferromagnetically spin-coupled tetranuclear copper(II) Schiff base complex [Cu4L2(3-ppz)2] (1) containing the 3-phenylpyrazole ligand has been prepared and structurally characterized. The crystal structure of 1 · 6H2O shows the formation of a decameric water cluster having two dimeric and one cyclic chair hexameric water aggregate anchored onto two complex units through hydrogen bonding interactions.Figure optionsDownload full-size imageDownload as PowerPoint slide
