Том 61, № 13 (2016)

Data on the structure, properties, and reactivity of one of the least studied 3D aromatic clusters—nonahydro-closo-nonaborate anion [B₉H₉]^2–—have been systematized. It has been shown that the key aspects of its reactivity are related to structural flexibility, which essentially distinguishes the [B₉H₉]^2– anion from the higher representatives of closo-borate anions.

In the framework of the search for promising anode materials for lithium-ion batteries and with the aim of studying the behavior of silicon–carbon composites during cycling, quantum-chemical modeling of the structure, stability, and electronic properties of silicon-coated carbon fibers has been performed. Calculations of loose infinite nanofibers [Si_nC_m]_k (k = ∞) for n = 12–16 and m = 8–19 have been performed by the density functional theory method with inclusion of gradient correction and periodic boundary conditions. It has been demonstrated that infinite nanofibers Si_nC_m have a large number of voids, promising for the accumulation of lithium without noticeable changes in lattice parameters, and a near-zero gap. The lithiation–delithiation of the Si₂₁ cluster and infinite nanofibers [Si₁₆C₁₉] for Li: Si = 1: 1, 2: 1, 3: 1, and 4: 1 has been modeled.