Thermal stability of hexaprismane C12H12 and octaprismane C16H16

Abstract

The results of quantum mechanical calculations of elementary prismanes-hexaprismane C 12 H 12 and octaprismane C 16 H 16 -have been presented. Their stability has been investigated in terms of the density functional theory and nonorthogonal tight binding model, and the heights of potential barriers pre venting isomerization and decay have been determined. It has been established based on the analysis of the molecular dynamics data and the hypersurface of the potential energy of these metastable compounds that hexaprismane and octaprismane have a rather high kinetic stability, which indicates the possibility of the for mation of carbon polyprismanes for applications in microelectronics and nanoelectronics, power engineer ing, pharmaceutics, metrology, and information technologies.

Geometry, Energy, and Some Electronic Properties of Carbon Polyprismanes: Ab Initio and Tight-Binding Study

“…The binding energies of hexaprismane and octaprismane in terms of NTBM model were 4.56 and 4.47 eV/atom, respectively. These results agree well with our data found using the DFT/B3LYP/6-311G: 4.50 and 4.40 eV/atom for hexaprismane and octaprismane, respectively [13]. It should be noted that ab initio methods (say density functional theory) are very accurate but computer-resources demanding and hence applicable to small systems only.…”

“…It is established that polyprismanes are molecular auxetics, that is, compounds having negative Poisson's ratio [12]. In addition, high kinetic stability of small prismanes (namely, [2,6]prismanes and [2,8]prismanes) is also confirmed via direct molecular dynamics simulations [13]. Long [n,m]prismanes with the large values of are of special interest.…”

Silicon buckyballs versus prismanes: Influence of spatial confinement on the structural properties and optical spectra of the Si18H12 and Si19H12 clusters

“…At the same time, attempts to place a carbon atom inside the silicic cage were unsuccessful, due to the loss of prismatic identity of such systems . The use of carbon prismanes as molecular containers is also very challenging if not expectedly impossible, and although these nanosystems possess the moderate stability, their spatial dimensions are too limited to host any atoms on its inside. Currently, Si and Ge are the only elements that are suitable for endohedral prismanes construction.…”

Coexistence of Normal and Auxetic Behavior in a Thermally and Chemically Stable sp3 Nanothread: Poly[5]asterane

“…Threem embers of this family, namely, [ 3]prismane, [11] [4]prismane (cubane), [12] and [5]prismane [13] were synthesized.Experimental and computationala ttempts to find intramolecular [2+ +2] photocycloaddition pathways toward [7]prismane and it analogues were also made in the past. [16] The steric strain in prismane materials can be reduced significantly by extending their framework by introducing additional functional groups.F or example, asterane molecules can be formed by introducing methylene groups (CH 2 )i nto the lateral edges of prismanes, as shown in Scheme 1b.B i [4]asterane and its substituted derivatives weres uccessfully synthesized. [15] Additional computational studies using DFT andt he non-orthogonalt ight-binding model were performed to ascertain the thermals tability of [6]prismane and [8]prismane and revealed rather high kinetic stability.…”

“…[15] Additional computational studies using DFT andt he non-orthogonalt ight-binding model were performed to ascertain the thermals tability of [6]prismane and [8]prismane and revealed rather high kinetic stability. [16] The steric strain in prismane materials can be reduced significantly by extending their framework by introducing additional functional groups.F or example, asterane molecules can be formed by introducing methylene groups (CH 2 )i nto the lateral edges of prismanes, as shown in Scheme 1b.B i [4]asterane and its substituted derivatives weres uccessfully synthesized. [17] In general, it has been shown by quantumc hemicalc alculations that the strain energy in the asterane molecules is lower than that in the corresponding prismane analogues.…”