Osmium compounds hydride derivatives

Other volatile compounds of elements can be used to transport samples into the plasma flame. For example, hydride reduction of mercury compounds gives the element (Hg), which is very volatile. Osmium can be oxidized to its volatile tetroxide (OSO4), and some elements can be measured as their volatile acetylacetonate (acac) derivatives, as with Zn(acac)2. 

Two pseudo-sugars of P-L-allo and a-D-manno have been prepared from the preceding intermediate 143 as follows. Reduction of 143 with diisobutyl aluminium hydride afforded the 3-hydroxyl derivative (155), which gave the 3-O-acetyl derivative (156) on acetylation. Hydroxylation of 156 with osmium tetroxide and hydrogen peroxide gave the compound (157), m.p. 154-155 °C, [a] 1 +71.5° (chloroform), as a main component (53% yield) and an unidentified compound, m.p. 191-193 °C, [a.] —7.9° (chloroform), as a minor component (6% yield). On acetylation, 157 was converted into the tri-0-acetyl derivative (158), m.p. 66-67 °C, [a]23 +41.8° (chloroform). 

Protonation of 322 with tetrafluoroboric acid in diethyl ether gives the cyclohexadienyl derivative 325 in 70% yield. Treatment of 325 with lithium aluminum hydride yields the biscyclohexadienyl osmium(II) complex 326. Treatment of 322 with PMe3 at 60°C gives the hydridophenyl osmium-(II) complex 181, rather than the expected arene bistrimethylphosphine osmium(O) compound, via intramolecular C—H bond activation of the benzene ligand (192,193) (Scheme 38). Compound 181 as well as the analogous ruthenium complex (92) have also been obtained directly by cocondensation of osmium or ruthenium atoms with benzene and tri-methylphosphine (62) [Eq. (44)]. 

Ruthenium and osmium are found together in the hydride-containing RuOs3(p-H)2(CO)i3 and the authors also report a triphenylphosphine derivative of this compound. 

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