Research ArticleMATERIALS

Carbyne with finite length: The one-dimensional sp carbon

See allHide authors and affiliations

Science Advances  30 Oct 2015:
Vol. 1, no. 9, e1500857
DOI: 10.1126/sciadv.1500857

eLetters is an online forum for ongoing peer review. Submission of eLetters are open to all . Please read our guidelines before submitting your own eLetter.

Compose eLetter

Plain text

  • Plain text
    No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Author Information
First or given name, e.g. 'Peter'.
Your last, or family, name, e.g. 'MacMoody'.
Your email address, e.g. higgs-boson@gmail.com
Your role and/or occupation, e.g. 'Orthopedic Surgeon'.
Your organization or institution (if applicable), e.g. 'Royal Free Hospital'.
Statement of Competing Interests
CAPTCHA

This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

Vertical Tabs

  • RE: Authors' response to eLetter from Buseck, Tarakeshwar, Nemeth and Kroto

    Comments. The paper by Pan et al. Sci. Adv. 2015; 1:e1500857 (1) has serious problems regarding their claim of having found a finite-length, one-dimensional sp carbon allotrope. Our Response. We don't agree with the above comment. Our reasons are given below.

    Comment #1. Identification/Nomenclature: Carbyne is an allotrope of carbon consisting of chains of sp-hybridized carbon atoms (2,3). As an allotrope, it should contain only carbon, but chemical data of Pan et al. (1) do not permit this conclusion. Their analytical data are from X-ray energy dispersive spectrometry (EDS), which cannot measure hydrogen, and the claim that oxygen in their sample comes from adsorbed molecules and gold from the catalyst is unproven and unlikely. We contend that the presence of any other element or bulky end group to stabilize a material consisting of carbon atoms no longer makes it an allotrope of carbon. The stability analysis of their sample (Section 4, Supplementary Information, and Fig. 3F) was done on hydrogen-capped carbon chains. By analogy, hydrogen peroxide and dimethyl peroxide could be considered to be allotropes of oxygen, which they clearly are not.

    Our Response. First, all spectroscopic analyses including Raman spectra did not detect the presence of any C-H bond in our product. Therefore, we can conclude that "spectroscopic analyses confirm that the product is of the structure of the sp hybridization with the alternating carbon–carbon singl...

    Show More
    Competing Interests: None declared.
  • RE: Carbyne remains elusive
    • Peter R. Buseck, Regents' Professor, School of Molecular Sciences and School of Earth and Space Exploration, Arizona State University
    • Other Contributors:
      • Pilarisetty Tarakeshwar, Associate Research Professor, School of Molecular Sciences, Arizona State University
      • Péter Németh, Research Scientist, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences
      • Harold W. Kroto, Professor, Department of Chemistry & Biochemistry, Florida State University

    The paper by Pan et al. Sci. Adv. 2015; 1:e1500857 (1) has serious problems regarding their claim of having found a finite-length, one-dimensional sp carbon allotrope:
    1. Identification/Nomenclature: Carbyne is an allotrope of carbon consisting of chains of sp-hybridized carbon atoms (2,3). As an allotrope, it should contain only carbon, but chemical data of Pan et al. (1) do not permit this conclusion. Their analytical data are from X-ray energy dispersive spectrometry (EDS), which can not measure hydrogen, and the claim that oxygen in their sample comes from adsorbed molecules and gold from the catalyst is unproven and unlikely. We contend that the presence of any other element or bulky end group to stabilize a material consisting of carbon atoms no longer makes it an allotrope of carbon. The stability analysis of their sample (Section 4, Supplementary Information, and Fig. 3F) was done on hydrogen-capped carbon chains. By analogy, hydrogen peroxide and dimethyl peroxide could be considered to be allotropes of oxygen, which they clearly are not.
    2. Lack of reliable standards, circularity: The paper provides several “carbyne” measurements that are presented as new, with the circularity issue of using their own data as “standards” for their experimental results. An example is their use of a linear structure for C10H2 for calculating the Raman spectrum (Fig. S3, p.15 of Supporting information), which is then used to prove that they obtained carbyne. The peaks at...

    Show More
    Competing Interests: None declared.
  • A Response to Kudryavtsev's comments
    There is a recognized understanding that " On all accounts, the resulting products or materials are ill-defined; definitive evidence for the existence of carbyne has not been obtained and its specific properties have not yet been determined" before our paper was published (Nature Chem. 2, 912 (2010), Nat Chem. 2, 967–971 (2010), Chem. World 7, 11 (2010)). We claimed that "We have, for the first time, synthesized the carbyne crystals with one-dimensional sp-hybridized carbon atoms under ambient conditions in the laboratory" based on these experimental evidence below. (1) We, for the first time, produce the carbyne crystals with the hexagonal structure, which are supported by the perfect XED pattern, the detailed SAED pattern from the three directions in the TEM analysis, and the structural stability analysis based on the first principle calculation. These carbyne crystals, the condensed phase of carbyne, are the white powders (so-called white carbon). Up to date, no peoples have synthesized this condensed phase of carbyne with the well-defined morphology and crystalline structure. Note that the resulting products or materials are ill-defined in previous reports. Additionally, in theory, Heimann et al. ever discussed the hexagonal structure of carbyne in 1983 (Nature 306, 164–167 (1983)). (2) We, for the first time, show the first entire Raman spectrum of the carbyne crystals, in which two sharp peaks at 1050 and 2175 cm-1 are characteristic of carbon-carbon single bond and...Show More
    Competing Interests: None declared.
  • The stable form of carbyne has been synthesized since 1992

    The authors claim a breakthrough in the synthesis of carbyne. Such work should include a complete review of all key articles on this topic. However, it was not done. One gets the impression that the authors are not familiar with the results that are most similar to their ones but received and published much earlier. These are the results of the research group from Moscow State University (MSU, Russia). Note that the authors know works of this group, but for some reason, they referred to the one earliest paper only [1]. Later, in 1992 MSU group reported the first synthesis of the stable carbyne form in which chains are oriented normal to the surface [2] - what is the same as claimed in the article under discussion. Oriented form of carbyne has been studied at Moscow State University [3-5] since 1992. United States Patents had been obtained [6-7]. It was found and published many interesting results which are very similar to the published in the present article. In both cases, carbyne is polymorphic: the distance between chains lies in ranges of 3-5 A, and their two-dimensional packaging can be 2 types: rectangular and hexagonal-with-center. A comparison of the new "2015 form" with the "1992 oriented form" for the case of hexagonal lattices is presented in Fig. 1-4.
    As can be seen from the figures, the old and the new results are identical. The main difference is in the Raman (Fig. 3): width of the peaks is significantly different. This can be explai...

    Show More
    Competing Interests: None declared.
    Attachments

Stay Connected to Science Advances

Navigate This Article