Cyclophyne chemistry: synthesis and study of an octacobalt complex of [8.8]paracyclophaneoctayne

Carbon‐Rich Compounds: Acetylene‐Based Carbon Allotropes

“…Just as in the case of the proposed transformation of multicyclic polyyne C 60 H 6 (31a) into [60]fullerene under mass spectrometric conditions, it was assumed that a similar cyclization of polyyne-bridged paracyclophanes 34a and 34b would give C 36 of D 6h symmetry. Polyynes 34a and 34b are larger homologues of the polyyne-bridged [8.8]paracyclophane that has eluded synthesis [122], and are generated from the corresponding propellane derivatives 35a and 35b by [2 + 2] cycloreversion [123]. In the LD TOF mass spectrum of 35a (negative mode), the cycloreversion took place cleanly to form C 36 H 8 -(34a -).…”

Macrocycles Based on Phenylacetylene Scaffolding

“…An alternate approach to tetrayne-linked systems is the use of organometallic fragments to stabilize a strained annulene with the subsequent liberation of the hydrocarbon. With sp bond angles calculated to be around 162h, PTeM 338 would be highly strained and was therefore expected to be quite reactive [105]. The octacobalt complex 339, on the other hand, should be readily isolable.…”

Explosionen als Synthesemethode? Cycloalkine als Vorstufen für Fullerene, Buckyröhren und Buckyzwiebeln

“…Die Zersetzungsprodukte, die nicht näher charakterisiert wurden, werden als braunes, polymeres Gemisch beschrieben. Das zweite Beispiel, das [8.8]Paracyclophanoctain 10, [14] konnte lediglich in seiner geschützten Form isoliert werden, in der vier der acht Alkinylgruppen als m-Acetylendicobalthexacarbonyl komplexiert sind. Versuche, den hochgespannten Kohlenwasserstoff 10 aus seinem Octacobaltkomplex freizusetzen, führten lediglich zu groûen Mengen unlöslichen Materials.…”