The synthesis and characterization of a mixed carboxylate paddle-wheel copper complex, with formula [Cu(µ-Pip)(µ-MeCO 2)(MeOH)] 2 (Pip = piperonylate or 1,3benzodioxole-5-carboxylate and MeCO 2 = acetate), is here reported. The described compound is a binuclear complex, each pair of similar carboxylate ligands occupying mutually trans bridging positions, while the methanol occupies the apical positions. The dimers are arranged into 2D layers in the bc plane through a network of O-H•••O hydrogen bonds stablished between the methanol and the acetate ligand. Magnetic studies showed a strong antiferromagnetic Cu•••Cu interaction (J =-308 cm-1), in agreement with the presence of four µ-κO-κO' carboxylates bridging the metallic centers in the binuclear complex.

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The reaction of copper(ii) acetate monohydrate with p-hydroxycinnamic acid (HpOHcinn) and different pyridine derivatives (4-tert-butylpyridine, 4-tBupy; 4-acetylpyridine, 4-Acpy; 3-phenylpyridine, 3-Phpy; 4-phenylpyridine, 4-Phpy) was essayed in methanol solvent at room temperature. The crystal structures of the resulting compounds were elucidated. Their analysis shows that the choice of pyridine ligands determines different coordination modes of the pOHcinn ligand and the Cu(ii) coordination, nuclearity and geometry. The pOHcinn acts as a monodentate carboxylate ligand in combination with 4-tBupy or 4-Phpy, yielding monomers and dimers, associated by hydrogen bonds into supramolecular networks in which the phenol group plays a key role. Conversely, in combination with 4-Acpy or 3-Phpy, the phenol group coordinates directly to the Cu(ii), acting as a ditopic ligand and yielding 2D coordination polymers. The compound containing 3-Phpy shows interesting MeOH-H2O reversible exchange behavior. Not only has the pyridine auxiliary ligand had a tremendous effect on the coordination mode of pOHcinn, but also its reactivity is influenced. Particularly, in the case of the compound containing 4-Phpy, it undergoes a photoinduced process, in which the phenol group deprotonates and coordinates to Cu(ii) as a phenoxy ligand. This yields a coordination polymer in which two different dimers alternate, bridged by the resulting pOcinn ligand. The magneto-structural correlation of this compound is also discussed.

Incorporation of one or two o-carborane moieties at the backbone of the pyrazole ring was achieved by lithiation and nucleophilic addition onto the corresponding 3,5-dimethyl-1-(2-toluene-p-sulfonyloxyethyl)pyrazole. Two monosubstituted carboranyl pyrazoles (L2...

Three different paddle wheel compounds have been synthesized, each one via a different synthetic pathway. The first method is the reaction of Cu(MeCO2)2 H2O with 1,3-benzodioxole-5-carboxylic acid (Piperonylic acid, HPip) in a MeOH solution, yielding [Cu(m-Pip) 2(MeOH)]2 (1). The second method is the transformation of the heteroleptic core paddle-wheel compound [Cu(m-MeCO2)(m-Pip)(MeOH)]2 into the homoleptic core paddle-wheel [Cu(m-Pip)2(DMSO)]2 2DMSO (2). Lastly, the third method is the substitution of the solvent molecule (DMF) present in the molecular array [Cu(m-Pip)2(DMF)]2 by 2-benzylpyridine (2-Bzpy) ligand, resulting in [Cu(m-Pip)2(2-Bzpy)]2 2.5MeOH H2O (3a). All compounds are characterized via EA, PXRD, ATR-FTIR, Far-IR and UV-Vis spectroscopy. For all three compounds, the X-ray crystal structure has been determined and their extended structures are discussed. Finally, TG/ DTA measurements have been recorded...