Carbyne Forms of Carbon: Do They Exist?

  title={Carbyne Forms of Carbon: Do They Exist?},
  author={P. P. K. Smith and Peter R. Buseck},
  pages={984 - 986}
Almost 15 years have passed since carbynes entered the literature as new forms of elemental carbon. They recently attracted attention as possible interstellar dust constituents and as carriers of presolar noble gases in meteorites. Their existence and that of the related mineral chaoite are questioned, and a reevaluation of previous data is suggested. 

The Nature of Carbyne- Pros and Cons

There is still controversy whether carbyne is an all-carbon sp-hybridized allotrope of carbon, i.e. the ‘third form of carbon’. However, more and more papers appear that strongly suggest carbyne may

Are crystalline C‐(H‐O‐N) carbons the elusive meteoritic carbynes?

I present an internally consistent reinterpretation of carbyne diffraction data making a few plausible assumptions. The results support that carbynes could be crystalline, randomly interstratified

Elemental carbon as interstellar dust

  • C. Pillinger
  • Physics, Geology
    Philosophical Transactions of the Royal Society of London. Series A: Physical and Engineering Sciences
  • 1993
C60 has not yet been detected in primitive meteorites, a finding that could demonstrate its existence in the early solar nebular or as a component of presolar dust. However, other allotropes of

Carbynes: Advances in the field of linear carbon chain compounds

Synthetic approaches to preparing carbyne, a linear carbon allotrope, including the chemical and physical methods are briefly considered. Modern structural models of carbyne, some of its properties,

Organic matter in carbonaceous chondrites

Carbonaceous chondrites are objects of great interest for chemists and astrophysicists. They contain a large number of abiogenic organic molecules and they are fragments of the least metamorphized

Carbon allotropes: beyond graphite and diamond

Carbon offers unmatched versatility among the elements of the periodic table. Depending on its hybridization state and atomic arrangement, carbon forms the layered semiconductor graphite, the

Heavier Carbon Subchalcogenides as C3 Sources for Tungsten-Capped Cumulenes: A Theoretical Study.

Heavier carbon subchalcogenides C3E2 serves as a source of C3 units for building C3n carbon sp-hybridized allotropes and can bind to transition metals through either a C═C or a C─E double bond.



Carbon: Observations on the New Allotropic Form

The recently characterized " white " allotropic form of carbon has been produced at high temperature and low pressure during graphite sublimation and the interplanar spacings are identical to those of a carbon form noted in graphitic gneiss from the Ries Crater.

Carbon: A New View of Its High-Temperature Behavior

An increasing body of research indicates that carbon can exist in a number of polymorphic "carbyne" forms. It is proposed that these forms occur because of a shift to triple bonding in the carbon

Carbynes: Carriers of Primordial Noble Gases in Meteorites

Five carbynes (triply bonded allotropes of carbon) have been found by electron diffraction in the Allende and Murchison carbonaceous chondrites: carbon VI, VIII, X, XI, and (tentatively) XII. From

Carbon: A Suggested New Hexagonal Crystal Form

Evidence for a new polymorphic form of carbon, similar to but distinct from chaoite, has been discovered in graphitic carbons under free-vaporization conditions at low pressures, with temperatures above approximately 2550�K.

Graphitic carbon in the Allende meteorite: a microstructural study.

High-resolution transmission electron microscopy, shows that carbon in the Allende carbonaceous chondrite meteorite is predominantly a poorly crystalline graphite. Such material is of interest as an

Carbynes in Meteorites: Detection, Low-Temperature Origin, and Implications for Interstellar Molecules

Although carbynes have been known to form only by condensation of carbon vapor above 2600 K or by explosive shock of > 600 kilobars, it is found that they also form metastably by the reaction 2CO → CO2 + C (solid) at 300� to 400�C in the presence of a chromite catalyst.

A New Allotropic Form of Carbon from the Ries Crater

A new allotropic form of carbon occurs in shock-fused graphite gneisses in the Ries Crater, Bavaria, and electron-probe analyses indicate that the new phase is pure carbon.

The P, T phase and reaction diagram for elemental carbon, 1979

A brief history of the many investigations of the pressure/temperature phase diagrams of elemental carbon is given. The strengths and weaknesses of the various proposed diagrams are discussed, and