Ion/molecule reactions of carbon cluster ions (Cn'+, n = 10-20) in the gas phase with crotononitrile (CRN) were investigated by Fourier transform ion cyclotron resonance spectrometry (FT-ICR). The carbon cluster ions studied were generated by electron impact ionization of perchlorinated aromatic compounds and subsequent elimination of all C1 substituents from the molecular ion. Clear pseudo-first-order reactions were observed for the carbon cluster ions Cn*+ thus formed without any sign of isomeric clusters of different reactivity. AM1 calculations of the stability of C&l, ( x = 4 , 6 , 8 ) derived from octachloronaphthalene indicate that the most stable monocyclic C,'+ are formed by this method. The reactions of C,'+ with C R N at a low operating pressure (1.2 X 1o-S-8.0 X le7 mbar) include the formation of adduct ions stabilized by radiative emission or/and loss of a neutral species (H or HCN) from the adduct ion. Rate constants for the reaction with C R N are distinctly larger than for the cluster reactions with H C N and acrylonitrile, and an exceptionally large reaction efficiency is found for C13*+ and C17*+. This correlates inversely with the thermochemical stability of the carbon clusters. The nature of the reaction products depends on the C number of C,'+. Consecutive reactions of the primary product ions Cn+4H4N+, formed by loss of H from the adduct ion, were observed only for reactions of even numbered Cn'+. On collision induced dissociation (CID) the adduct ions from Cn*+ ( n = 11, 13) redissociate to the original cluster ion while the adduct ions of C17*+ lose C3 and c 6 (2C3). A reaction model explaining these observations is proposed.
Sodium Phosphaethynolate as a Building Block for Heterocycles. -NaOCP is a useful building block to synthesize a variety of phosphorus-containing five-and six-membered heterocycles in good yields. In contrast to its nitrogen analogue NaOCN, the triple bond in NaOCP undergoes [2 + 2], [3 + 2], and [4 + 2] cycloadditions. -(CHEN, X.; ALIDORI, S.; PUSCHMANN, F. F.; SANTISO-QUINONES, G.; BENKO*, Z.; LI, Z.; BECKER, G.; GRUETZMACHER, H.-F.; GRUETZMACHER, H.; Angew.
Das aus Naphthazarin (I) und dem Dien (II) erhältliche Addukt (IIIa) [Röntgenstrukturanalyse (RSA): P2,2,2,; Z=4] wird über das Epoxid (IV) zum Olefin (VIa) umgesetzt.
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