Graphene smaller amplitude and higher frequency. This phenomenon, named "membrane effect", was predicted by Lifshitz in 1952. A prediction that was published in 2015 suggested a melting point of ≈4125 K. Recent and more sophisticated modelling has increased this temperature to at least 5000 K. At 6000 K (the sun's surface having an effective temperature of 5,777 K) graphene melts into an agglomeration of loosely coupled doubled bonded chains, before becoming a gas. The carbon–carbon bond length in graphene is about 0.142 nanometers. Graphene sheets stack to form graphite with an interplanar spacing of . Graphene is the strongest material ever
Carbon–carbon bond triple bond are 134 pm and 120 pm, respectively. Also a consequence of its severe steric congestion, hexakis(3,5-di-"tert"-butyl)ethane has a greatly elongated central bond with a length of 167 pm. On the other hand, a very short triple bond of 115 pm has been observed for the iodonium species [HC≡C–IPh][CFSO], due to the strongly electron-withdrawing iodonium moiety. Carbon–carbon bond A carbon–carbon bond is a covalent bond between two carbon atoms. The most common form is the single bond: a bond composed of two electrons, one from each of the two atoms. The carbon–carbon single bond is a sigma bond and