Tricyclopentadienyl lanthanide

C5H5)3Eu THF. The THF complexes exhibit a bathochromic shift in their color because of the coordination of the oxygen to the rare earth metal. Tetrahydrofurane adducts with 2 and 3 THF coordinated to the tricyclopentadienyl lanthanide complex are also known (Suleimanov et al., 1982c). 

Tricyclopentadienyl rare earth compounds form stable 1 1 adducts with many bases. THF adducts have been described for yttrium, lanthanum and nearly all lanthanides (Manastyrskyj and Dubeck, 1964 Calderazzo et al., 1966 E.O. Fischer and H. Fischer, 1966 R.D. Fischer and H. Fischer, 1967 Pappalardo, 1969 Raymond and Eigenbrodt, 1980 Rogers et al., 1981 Deacon et al., 1982). Tetrahydrofuran can be removed in high vacuum from all the complexes except for... 

Iodine cleaves one erbium-cyclopentadienyl bond in tricyclopentadienyl erbium with formation of pink dicyclopentadienyl erbium iodide (Maginn et al., 1963), and the tricyclopentadienyl complexes of neodymium and ytterbium are cleaved by hydrogen cyanide with formation of the corresponding dicyclopentadienyl lanthanide cyanide (Kanellakopulos et al., 1974). The colors and some physical data of the cyclopentadienyl rare earth halides and cyanides are given in table 4. 

Table 7 gives the chemical shifts, the paramagnetic H NMR shifts and the line width of some lanthanide tricyclopentadienyls. The extreme line broadening caused by very long relaxation times of Gd and Er are the reason, that no resonances are detected for the gadolinium and the erbium derivatives (Von Ammon et al., 1969 R.D. Fischer, 1973). 

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