Trinuclear anions

In the chromium triad, the only claimed tetranuclear compound is the anion [Mo4(CO)u ]2 which was mentioned together with [Mo3(CO)14]2, in a study of the reaction of sodium tetrahydroborate and hexacarbonyl-molybdenum in liquid ammonia14). Later work failed to confirm the existence of the trinuclear anions, [M3(CO)i4]2 (M = Cr, Mo, W)109 1S0,169 and, therefore, the real existence of the tetranuclear anion also seems dubious. 

XjYs structure, type, 35 283 Halo-chalcogenates(IV), 35 246-255 degradation, 35 247-248 di-and trinuclear anions, 35 247, 249-251 hexahalochalcogenates(IV), 35 251-253 nonahalodichalcogenates(IV), 35 252-253 polymeric species, 35 254-255 in solvents, 35 247 Haloenzyme, 22 424 p-Halogen, see Parahalogen Halogenation, of hexafluoroacetone, 30 302-303... 

This method has the advantage of generating the desired anions quantitatively and avoids the formidable task of separating mixtures of polynuclear anions into their analytically pure components. The trinuclear anions may be isolated as alkali metal salts and used in situ or may be quantitatively metathesized to form alkyl ammonium, arsonium, or phosphonium salts. Therefore, we have found these alkali metal dianions to be a very useful, general starting material for a variety of reactions. 

Trinuclear anions, (Hg2MCls)2, linked by Cl bridges involving the terminal Hg—Cl bonds... 

Trinuclear anions as above, linked by the HgCIM bridging Cl atoms... 

Iron-sulfur systems containing three iron atoms are uncommon, and so the reported synthesis (42) of such a trinuclear anion [Fe3S2-(NO)5] was of great interest, particularly as it was also reported that this anion, although an even-electron species, gave ESR spectra under a wide range of conditions. 

A single oxo bridge may subtend an angle between 140° and 180°, this angle being determined by steric or electronic factors (Table 3).95 103 Almost all these examples refer to the solid state, but there are also several homo- and hetero-nuclear M—O—M and M—O—M—O—M species known in solution. Often these are intermediates in, or products of, electron transfer reactions with oxide-bridging inner-sphere mechanisms. Examples include V—O—V in V(aq)2+ reduction of VO(aq)2+, and Act—O—Cr in Cr(aq)2+ reduction of UOj+ or PuOj+ a useful and extensive list of such species has been compiled. Tlie most recent examples are another V—O—V unit, this time from VO(aq)2+ and VOJ,105 and an all-actinide species containing neptunium(VI) and uranium-(VI).106 An example of a trinuclear anion of this type, with the metal in two oxidation states, is provided by (31).107... 

Similarly, the trinuclear anionic AuVAu111 complexes PPN[(C6F5)Au p,-PPh2 CH(AuX)PPh2 Au(C6F5)3] (X = Cl, Cgl s) are obtained when the same dinuclear methanide is treated with one equivalent of [AuX(tht)] instead of [Au(PPh3)(tht)]C104 [Eq. (32)].90... 

Table 1, p. 400) show that they all possess the trinuclear anionic unit [Hg2MCl8] (M = Pd or Pt) (10). 

Reaction of the tertiary phenylstibine with BuLi/crown ether yielded the complex [Li(12-crown-4)2][Sb3Ph4]-THF containing the bent trinuclear anion [Ph2SbSbSbPh2] with a SbSbSb angle of 88.8° and CSbC angle of 92.7°. The Sb—Sb bond distances are to 276.1 pm, whereas the Sb—C bond lengths are 216.6 pm and 219.0 pm . 

The preparation and i.r. spectra of the tetraphenylphosphonium salts of the trinuclear anions (52) with pure metal isotopes 64Zn, 68Zn, 92Mo, and... 

The only industrial application, the synthesis of butanol from propene (Reppe synthesis), was not very successful (297). This reaction is catalyzed by iron carbonyls in the presence of tertiary ammonium salts the trinu-clear cluster anion [HFe3(CO) ] detected in the reaction mixture has been discussed as the active species (298). Spectroscopic studies under CO pressure, however, showed the trinuclear anion [HFe3(CO) ]- to be converted into the mononuclear species [HFe(CO)4] (299), and this anion is now assumed to be the catalyst in the Reppe reaction (290). 

Trinuclear anions (4) of Cr and Mo are obtained by treating the hexacarbonyls with NaBH4 at the tetrahydrofuran reflux ... 

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