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Cluster contraction

More remarkably, the reaction forming the Mn-Pt species is unique among the compounds 144-149 in that three other metallacarborane products were also isolated from this system alone. These are two 12-vertex species, [l-Ph-2,2,2-(CO)3-7-X-8,8-dppe-/iyperc/oAo-8,2,l-PtMnCBgHg] pC = H (150), OEt (151)], and the complex [3,6,7- Mn(CO)3 -3,7-(p-H)2-l-Ph-6,6-dppe-c/oio-6,l-PtCBgH6] (152) formed by cluster contraction. Subsequent studies confirmed that the ethoxylated compound 151 is formed by reaction of 146 with adventitious EtOH present in the precursor 129. Indeed, treatment of 146 with other alcohols ROH afforded similar species [l-Ph-2,2,2-(CO)3-7-OR-8,8-dppe-/z3y crc/oA o-8,2,l-PtMnCBgHg] [R = Me (153), (CH2)20H (154), (CH2)40H (155)] with, surprisingly, only mono-cage products observed when diols were used as substrates. All of the alkoxy-substituted compounds 151 and 153-155 are relatively stable and do not react further, whereas... [Pg.31]

In most cases the prolonged treatment of a closo carborane or borane with strong base results in the removal of a single-boron vertex to yield a nido cluster, inert to further degradation. This principle is exploited in the polyhedral contraction and subrogation synthetic strategies. In the prototypical case. [Pg.246]

Further expansion of 13-vertex species or thermal metal transfer reactions leads to the 14-vertex cluster [(T -C H )Co]2C2B2qH22 [52649-56-6] and [52649-57-7] (199). Similar 14-vertex species have been obtained from tetracarbaboranes (203) and show unusual stmctures. The isomeric bimetallic cobaltacarborane complexes /(9j (9-(Tj -CpCo)2C2BgH2Q (cp = C H ) can be formed by either polyhedral expansion or contraction reactions. Six isomers of this cluster are formed in the thermally-induced intermolecular metal transfer and polyhedral expansion of the 11-vertex f/oj o-(ri -C H )CoC2BgH Q. [Pg.247]

Interestingly, compound 10 features the largest and hollow [Gd6] cluster without the support and contracted effect of a centered p6-oxo ligand. Except for the reported TI, unit in the [Thn] cluster [103-106], all previously known octahedral... [Pg.192]

See other pages where Cluster contraction is mentioned: [Pg.15]    [Pg.52]    [Pg.31]    [Pg.82]    [Pg.1581]    [Pg.40]    [Pg.15]    [Pg.52]    [Pg.31]    [Pg.82]    [Pg.1581]    [Pg.40]    [Pg.126]    [Pg.335]    [Pg.298]    [Pg.166]    [Pg.190]    [Pg.162]    [Pg.402]    [Pg.1097]    [Pg.130]    [Pg.33]    [Pg.122]    [Pg.91]    [Pg.76]    [Pg.29]    [Pg.36]    [Pg.189]    [Pg.80]    [Pg.97]    [Pg.287]    [Pg.72]    [Pg.515]    [Pg.287]    [Pg.138]    [Pg.229]    [Pg.24]    [Pg.199]    [Pg.272]    [Pg.21]    [Pg.124]    [Pg.177]    [Pg.195]    [Pg.205]    [Pg.249]   
See also in sourсe #XX -- [ Pg.31 ]

See also in sourсe #XX -- [ Pg.31 ]



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