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Preparations and structures of (π-C5H5)2NbI2 and (π-C5H5)2NbI3

1968; Elsevier BV; Volume: 12; Issue: 3 Linguagem: Inglês

10.1016/s0022-328x(00)88701-x

1872-8561

P. M. TREICHEL, Giuseppe Werber,

Synthesis and characterization of novel inorganic/organometallic compounds

Dicyclopentadienylniobium triiodide can be synthesized by halide ion exchange reaction from (π-C5H5)2NbCl2OH and NH4I in aqueous solution. This compound, in contrast to the other known (π-C5H5)2NbX3 compounds (XCl, Br), shows on tendency to hydrolyze. It can be crystallized as thin violet plates from dichloromethane. Dicyclopentadienylniobium diiodie is formed when (π-C5H5)2NbCl2OH is reduced by benzyl mercaptan in a methanol/benzene solution, in the presence of NH4I. This compound forms black, lustrous crystals, which are slightly air sensitive, though the compound itself is decomposed rapidly by air in solution. The compound is paramagnetic. The infrared spectrum of (π-C5H5)2NbI2 is almost identical with the spectrum of the analogous zirconium compound, suggesting similar structures. The infrared spectrum of (π-C5H5)2NbI3 supports a structure involving parallel or near parallel cyclopentadienyl rings. Models for such a system are proposed which strongly support this structure.