| Autor: |
Scriven LM; Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, U.K., Kaiser K; IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland., Schulz F; IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland., Sterling AJ; Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, U.K., Woltering SL; Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, U.K., Gawel P; Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, U.K., Christensen KE; Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, U.K., Anderson HL; Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, U.K., Gross L; IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland. |
| Abstrakt: |
Cyclo[18]carbon (C 18 , a molecular carbon allotrope) can be synthesized by dehalogenation of a bromocyclocarbon precursor, C 18 Br 6 , in 64% yield, by atomic manipulation on a sodium chloride bilayer on Cu(111) at 5 K, and imaged by high-resolution atomic force microscopy. This method of generating C 18 gives a higher yield than that reported previously from the cyclocarbon oxide C 24 O 6 . The experimental images of C 18 were compared with simulated images for four theoretical model geometries, including possible bond-angle alternation: D 18 h cumulene, D 9 h polyyne, D 9 h cumulene, and C 9 h polyyne. Cumulenic structures, with ( D 9 h ) and without ( D 18 h ) bond-angle alternation, can be excluded. Polyynic structures, with ( C 9 h ) and without ( D 9 h ) bond-angle alternation, both show a good agreement with the experiment and are challenging to differentiate. |
