Subscriber access provided by UNIV OF NEW ENGLAND ARMIDALE
C: Physical Processes in Nanomaterials and Nanostructures
Desorption of Fullerene Dimers upon Heating Non-IPR Fullerene Films on HOPG Jürgen Weippert, Lea Hohmann, Dmitry V. Strelnikov, Patrick Weis, Monica Loredana Pop, Artur Böttcher, and Manfred M. Kappes J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.8b12113 • Publication Date (Web): 11 Feb 2019 Downloaded from http://pubs.acs.org on February 16, 2019
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
The Journal of Physical Chemistry
Desorption of Fullerene Dimers upon Heating non-IPR Fullerene Films on HOPG Jürgen Weippert,† Lea Hohmann,† Dmitry Strelnikov,† Patrick Weis,† Monica L. Pop,‡ Artur Böttcher,∗,† and Manfred M. Kappes†,¶ †Institute of Physical Chemistry, KIT, 76131 Karlsruhe, Germany ‡Faculty of Chemistry and Chemical Engineering, University Babes-Bolyai Cluj-Napoca, 400084 Cluy, Romania ¶Institute of Nanotechnology, KIT, 76344 Eggenstein-Leopoldshafen, Germany E-mail:
[email protected] 1
ACS Paragon Plus Environment
The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Abstract Low energy ion beam deposition of mass-selected fullerene ions was used to generate thin films of non-IPR fullerenes, C2n (2n=48-58 and 52-68) on graphite under UHV. These were probed by mass-resolved thermal desorption spectroscopy. We observe the emission of dimers in addition to dominant monomer desorption for 2n=58-68 while for 2n=48-56 no dimer desorption was detected. Dimer signals were typically at < 1% level compared to the monomers. The desorption temperature ranges of these dimer species were higher and much narrower than for the corresponding monomers. Building also on theoretical considerations we came to the conclusion that coalescence reactions between the fullerenes must take place below 1000 K and that fullerenes with more than three pairs of adjacent pentagons cross-link too strongly to allow the desorption of dimers.
Introduction Conventional fullerenes like C60 or C70 have all-carbon, hollow cage structures consisting only of hexagons and (twelve) pentagons. They always contain an even number 2n of carbon atoms. A subset of these fullerene cages has no shared bonds between any two of their twelve pentagons which is why they are known as IPR fullerenes (Isolated Pentagon Rule, see fig. 1a). 1 By contrast fullerenes with adjacent pentagons (AP) sharing a C-C bond are called non-IPR fullerenes 2 and exhibit fundamentally different properties. In particular, AP sites make non-IPR fullerenes less stable and more reactive than IPR cages of similar size.
Whereas, the 1812 different conventional fullerene isomers which are possible for 2n=60 2 comprise both non-IPR and (one) IPR cages, all fullerenes, C2n , with 2n
