Structure and properties of o -carboranylalcohols pyridines metal complexes

DI SALVO, F.; PLANAS, J. G.; VIÑAS, C.; TEIXIDOR, F.; LIGHT, M. E.; HURSTHOUSE, M. B.

ACTA CRYSTALLOGRAPHICA A

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2011 vol. 67 p. 368 - 368

0108-7673

The recently reported series of ortho-carboranylmethylalcohols bearing pyridine substituens [1] opens a new door to the synthesis of very attractive carborane based transition metal complexes (Figure). The two different functionalities (OH and N) together with the chance to vary the nitrogen position along the aromatic ring, the metal, as well as the hydrophobic icosahedral heteroborane cluster, give place to compounds which exhibit different structural architectures and properties. When an ethanolic or acetone solution of orthocarboranylmethylalcohol pyridine or quinolyne derivatives is mixed with a solution containing the desired metallic ion, the corresponding complex is obtained. For instance, for Co(II), the 3- and 4- pyridine and 4-quinoline derivatives give place to tetrahedral geometries whereas the 2-pyridine ones, due to the carboranylalcohol acting as a N, OH/O bidentate ligand, conducts to octahedral or square planar complexes (Figure). On the other hand, when Fe(III) and the 2-pyridine ligands are employed, different structures are obtained depending on the carborane substituents (R in the Figure). For R = H, a pentacoordinated mononuclear complex crystallized as a result of the reaction while for R = Me, an iron dinuclear compound with three oxo bridges is obtained (Figure). Magnetic measurements of the Co complexes are in agreement with their different structures and in the particular case of the octahedral complex, the negative sign of θ indicates antiferromagnetic interactions among the monomeric units and matches well with the number of OH⋅⋅⋅Cl hydrogen bonds found in the crystal structure.Ref[1] V. Terrasson, Y. García, P. Farràs, F. Teixidor, C. Viñas, J. G. Planas, D. Prim, M. E. Light, M. B. Hursthouse, CrystEngComm, 2010, 12, 4109.