Uranium(iv) tetrathiolate complexes were made by (a) reaction of U(NEt,), with RSH (R = Et, Pr', Bun or But), (6) treatment of U(BH,), with RSH (R = Bun or Ph) or of U(SBun), with PhSH or (c) oxidation of uranium metal by RSSR (R = Et, Pri or Ph). Rearrangement of [U(SBut),(py)J (py = pyridine) in toluene gave the trinuclear cluster [U,S(SBut),,]with liberation of BUSH and Me,C=CH,.Reaction of U(SPri), with [NEt,H] (BPh,] in the presence of hexamethylphosphoric triamide (hmpa) afforded the cationic compound [U(SPr'),(hmpa),] [BPh,], which presents a trans-octahedral crystal structure. lodinolysis of U(SPri), in pyridine led to the formation of [U(SPr'),l,(py),] which adopts a pentagonal-bipyramidal configuration in its crystalline form. The trithiocarbonate ( PriS),C=S was obtained by reaction of U(SPri), with CS, .

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Solid amorphous cobalt oxysulfide “CoSOH” obtained by basic aqueous precipitation absorbs gaseous hydrogen up to a limit close to the H2/Co molar ratio of 0.5. To understand the nature of this phenomenon, the cobalt compound was characterized before and after hydrogen absorption (XRD, IR, TEM, XPS, inelastic neutrons scattering, and extended X-ray absorption fine structure spectroscopy). The initial oxysulfide is an amorphous solid containing hydroxide groups and sulfide moieties. Considerable amounts of hydrogen (as high as 0.3 mol of H2/Co atom) can be absorbed by this solid without any apparent changes of its structure and morphology, due to the reductive opening of S−S bridges leading to the formation of −SH groups. At higher levels of hydrogen consumption (0.3−0.5 mol of H2/Co atom), formation of crystalline Co9S8 compound was observed. Isotopic exchange and volumetric experiments demonstrated that the absorption of hydrogen is a slow and irreversible first-order solid−gas reaction.

Reduction of the uranium(IV) thiolates Cp* 2 U(SR) 2 (Cp* ) η-C 5 Me 5 , R ) Ph, Me, i Pr or t Bu) with sodium amalgam afforded the corresponding U(III) complexes Na[Cp* 2 U(SR) 2 ] (R ) Ph, 2a; Me, 2b; i Pr, 2c) or the U(IV) sulfide Na[Cp* 2 U(S t Bu)(S)]. C-S bond cleavage of a thiolate ligand was also observed during the thermal decomposition of 2c into the sulfide Na[Cp* 2 U(S i Pr)(S)], whereas 2b was transformed in refluxing THF into the thiametallacyclopropane complex Na[Cp* 2 U(SMe)(SCH 2 )], resulting from C-H bond activation of a SMe group. The X-ray crystal structures of [Na(18-crown-6)(THF) 2 ][Cp* 2 U(S i Pr) 2 ], [Na(18-crown-6)][Cp* 2 U(S t Bu)(S)], and [Na(18-crown-6)(THF) 2 ][Cp* 2 U(SMe)(SCH 2 )] have been determined.