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A general strategy for designing stable hypercarbon CB62−-based cluster-assembled compounds CpM(CB6)q− (M = Li, Na, K, Be, Mg, and Ca) is proposed. This approach takes advantage of (1) the extra st...

We predict the assembly and stabilization of the silicon-doped all-metal aromatic unit SiAl3- based on the density functional calculations on a series of model compounds [D(SiAl3)M]q- as well as the saturated compounds [D(SiAl3)Mn] ((D = SiAl3-, Cp-(C5H5-); M = Li, Na, K, Be, Mg, Ca) and the more extended sandwich-like species. For all six metals, SiAl3- can be assembled only in “heterodecked sandwich” scheme (e.g., [CpM(SiAl3)]q-) so as to avoid cluster fusion. Interestingly, among all the designed sandwich species, SiAl3- generally prefers to interact with the partner deck at the side (Al−Al or Al−Si bonds) or corner (Si or Al atoms) site, in contrast to the known decks such as Cp-, P5-, N42-, and Al42-, which take the traditional face−face interaction type. Such interaction types present an interesting growth pattern that might be applicable to the assembly of Si-doped all-metal aromatic SiAl3- units into highly extended sandwich complexes. Our results for the first time showed that the electronic, str...

The complete reaction mechanism of the platinum-mediated arene [(N−N)PtPh2 (N−N = diimine ArNCMe−CMeNAr with Ar = 2,6-Me2C6H3)] C−H activation has been investigated by using the B3LYP density functional theory method. The calculations show that the protonation should occur at the metal center, giving a coordinately unsaturated five-coordinate Pt(IV) hydride which is trapped by acetonitrile; otherwise monophenyl solvento cations (N−N)Pt(Ph)(NCMe)+ should be isolated and characterized spectroscopically. Of the H exchange process, oxidative addition−reductive elimination and σ-bond metathesis mechanisms (including direct σ-bond metathesis and indirect σ-bond metathesis) are considered. The indirect σ-bond metathesis, which goes through a two-step H migration, is dramatically higher in energy than that of the direct one, so we can safely rule it out. The barrier associated with direct σ-bond metathesis is 14.70 kcal/mol, to be compared with 20.56 kcal/mol found in oxidative addition. So, unlike the methane C−...