Acetylenic Cyclophanes as Fullerene Precursors: Formation of C60H6 and C60 by Laser Desorption Mass Spectrometry of C60H6(CO)12

Abstract

A logical precursor of macrocycle C H , cyclophane C H (CO) (1) represents a building block in a possible total synthesis of C . In Fourier transform ion cyclotron resonance laser desorption mass spectroscopic experiments in the negative-ion mode, 1 fragments to C H (2) under successive loss of CO. Further loss of six H atoms and rearrangement gives C ions with a fullerenic structure.

Synthesis of polyynes in a submerged electric arc in organic solvents

“…This synthetic approach led successfully to polyynes chains having m ¼ 12, hence having 24 carbon atoms [1]. The synthesis of polyynes through coupling reactions, although very complex, remained till now the almost unique method to produce these molecules [2][3][4][5][6][7]. Particular emphasis has been given in recent times to the stability of the polyynes; it has been shown that adequate stability can be achieved only if the chains are end-capped by bulky or special groups [2][3][4][5][6][7].…”

“…Recently, some new experimental results based on carbon vapour deposition on surfaces [16] and supersonic cluster beam soft deposition on surfaces [17] have completely revolutionized our knowledge on this carbon allotrope and reawakened the interest and the enthusiasm on this specific field. Notwithstanding the mentioned efforts and results, the access to polyynes (and carbyne) remained practically difficult either because of the complex synthetic approach of the classic organic chemistry [1][2][3][4][5][6][7] or because the need of extremely sophisticated and expensive apparatus [17]. Recently, Tsuji and colleagues have shown that polyynes in solution can be generated by laser ablation of graphite [18] or fullerene [19] particles suspended in an organic solvent.…”

“…In fact, polyynes are an important class of molecules because they are the intermediates involved in the fullerene formation [6,21] but are also the intermediates leading to polycyclic aromatic hydrocarbons and soot formation in all combustions and flames [22,23]. Furthermore, polyynes under the form of cyanopolyynes have been detected in space, in certain astronomical objects and are thought to be the contributors to certain optical feature of the diffuse interstellar bands of the interstellar light extinction curve and of the unidentified infrared bands [24][25][26][27].…”

The graphite arc-discharge in the presence of CCl4: Chlorinated carbon clusters in relation with fullerenes formation

“…graphite arc-discharge in He atmosphere) [1] has been commercially applied for many years, the formation mechanism for such kind of caged carbon clusters is still not well understood owing to the lack of viable evidences [2][3][4][5][6][7][8][9][10][11][12], notably the lack of the information on possible intermediates. Upon this process was established, efforts were primarily directed to support the interpretations proposed by pioneers that see a number of attempts [13][14][15][16][17] to trap intermediates for the fullerene formation by the addition of various agents to the inert gas buffer medium.…”

Laser Desorption Mass Spectrometry of End Group-Protected Linear Polyynes: Evidence of Laser-Induced Cross-Linking

“…35 Of particular importance to the topic of this paper are LDI experiments of polyyne-containing precursor molecules. Tobe et al 36 and Rubin et al 37 independently developed a strategy for the formation of fullerenes, which applies LDI for the conversion of cyclophane-implemented three-dimensional cyclic polyynes. For C 60 , all carbon atoms are already implemented in the precursor and the protecting groups are expelled under laser activation, followed by subsequent rearrangement to the fullerene product.…”