Richard R. Rietz

Preparation and properties of the actinide borohydrides: protactinium(IV), neptunium(IV), and plutonium(IV) borohydrides

All five actinide borohydrides are made by reaction of the anhydrous tetrafluoride with Al(BH/sub 4/)/sub 3/. Synthesis of Pa(BH/sub 4/)/sub 4/ is a modification of that of Th (BH/sub 4/)/sub 4/ by Hoekstra and Katz. The Np and Pu borohydrides were synthesized at O/sup 0/C, followed by cold trapping of the products at -78 and -196/sup 0/C. Physical properties of these borohydrides (color, stability, mp, vapor pressure, M/sup 4 +/ radius, structure, density, gas-phase infrared spectra) were compared with those of Th, U, and Hf borohydrides. (DLC)

PREPARATION OF ETA-CYCLOPENTADIENYLCOBALT(III) AND ETA-CYCLOPENTADIENYLNICKEL(IV) COMPLEXES OF THE ETA-7-B10CH11(3-) CARBOLLIDE LIGAND

Abstract : Abstraction of bridging protons from B10CH13(-) with ethanolic KOH followed by addition of C5H6 and anhydrous CoCl2 and subsequent oxidation produces a high yield of the ((eta-C5H5Co(III)(eta-7-B10CH11))(-) ion. Abstraction of N(CH3)3 and bridging protons from B10H12C(N(CH3)3) with sodium in THF followed by the addition of NaC5H5 and NiBr2-2C2H4(OCH3)2 and subsequent oxidation gives a low yield of (eta-C5H5)Ni(IV)(eta-7-B10CH11). Both metallocarboranes are isoelectronic and isostructural with the icosahedral two carbon species, (eta-C5H5)Co(III)(eta-B9C2H11), and contain the metal atom bonded to a B4C face. At 450C under high vacuum (eta-C5H5)Ni(IV)(eta-7-B10CH11) rearranges to a mixture of (eta-C5H5)Ni(IV)(eta-2-B10CH11) and (eta-C5H5)Ni(IV)-(eta-1-B10CH11). (Author)