Energies for cyclic and acyclic aggregations of adamantane and diamantane units sharing vertices,edges, or six‐membered rings |
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Authors: | Alexandru T Balaban Debojit Bhattacharya Douglas J Klein Yenni P Ortiz |
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Institution: | Texas A & M University at Galveston, Galveston |
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Abstract: | Diamondoids are hydrocarbons having a carbon scaffold comprised from polymer‐like composites of adamantane cages. This article describes computed total energies and “SWB‐tension” energies (often referred to as “strain” energies) for species having n adamantane or diamantane units sharing pairwise: one carbon atom (spiro‐n]adamantane or spiro‐n]diamantane); one C? C bond (one‐bond‐sharing‐n]adamantane or one‐bond‐sharing‐n]diamantane); or one chair‐shaped hexagon of carbon atoms (1234‐helical‐cata‐n]diamantanes). Each of the five investigated polymer‐like types is considered either as an acyclic or a cyclic chain of adamantane‐ or diamantane‐unit cages. With increasing n values, SWB‐tension energies for acyclic aggregates are found to increase linearly, while the net SWB‐tension energies of cyclic aggregates often go thru a minimum at a suitable value of . In all five cases, a limiting common energy per unit ( ) is found to be approached by both cyclic and acyclic chains as , as revealed from plots of versus 1/n for acyclic chains and of versus 1/n2 for cyclic chains. © 2015 Wiley Periodicals, Inc. |
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Keywords: | diamondoid hydrocarbons total and strain energy spiro‐adamantanes bond‐ and ‐hexagon‐sharing diamondoids cyclic and acyclic chains |
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