Microchemical preparation of tricyclopentadienyl compounds of berkelium, californium, and some lanthanide elements

Abstract

Tricyclopentadienyl complexes of Bk, Cf, and Pm were prepared by reaction of the trichlorides of these elements with molten Be( C5HS)2 in an apparatus developed for use with microgram quantities of radioactive substances. For comparison purposes the compounds Sm(CSHj)3 and Tb(C6Hj)s were prepared in the same way, and Pr(CaHa)3, Sm(CsHs)a, and Gd(CjHs)s were made in gram quantities. The identities of the compounds were established by X-ray powder diffraction methods. Unit-cell dimensions and the space-group symmetry of this isomorphous series were determined from single crystals. Visible absorption spectra were measured using microgram quantities of the radioactive specimens.

Optical Spectroscopy of f-Element Compounds

“…In CmCp3, several sharp bands were observed near 15600 cm" 1 upon excitation in the ultraviolet range, Laubereau and Burns (1970). These correspond well to expected 5 D 7 / 2 •* 8 S transitions in Cm 3+ .…”

Stannocene as Cyclopentadienyl Transfer Agent in Transmetalation Reactions with Lanthanide Metals for the Synthesis of Tris(cyclopentadienyl)lanthanides

“…Also, molten (C 5 H 5 ) 2 Be or (C 5 H 5 ) 2 Mg were used as cyclopentadienyl transfer reagents with LnX 3 16, and C 5 H 5 Tl 17 or (C 5 H 5 ) 2 Hg 18 in transmetalation reactions with rare earth metal powders [Equation (2)] to yield (η 5 ‐C 5 H 5 ) 3 Ln 4.…”

Metal ion - molecule reactions of Bk+: comparison with Pu+ and Tb+

“…Regarding the organometallic chemistry of Bk, the only well-characterized organometallic compound is the ionic trivalent tris-cyclopentadienyl compound, Bk(C 5 H 5 ) 3 , in which the Bk(III) metal center is π-bonded to the cyclopentadienylide ligands: Bk 3+ -η 5 -(C 5 H 5 − ) 3 [15]. No organoberkelium compounds with covalent Bk−C σ-type bonding have been reported.…”