Asymmetrisch substituierte Iminiumsalze [Et3PNAsPh3]X und ihre Reaktion mit Acetonitril. Kristallstrukturen von [Et3PNAsPh3]X (X = Cl,Br), [(Ph3As)2CCN]Br und [(Ph3As)2CCN(SnBr5)]

Asymmetrically Substituted Iminium Salts Et₃PNAsPh₃]X and their Reactions with Acetonitrile. Crystal Structures of Et₃PNAsPh₃]X (X = Cl, Br), (Ph₃As)₂CCN]Br, and (Ph₃As)₂CCN(SnBr₅)] The asymmetrically substituted iminium salts Et₃PNAsPh₃]X with X = Cl, Br are formed in the reaction of Me₃SiNPEt₃ with Ph₃AsX₂ at 180 °C in the melt. The products crystallize from acetonitrile as colourless, moisture-sensitive crystals, which crystallize isotypicly in the space group P2₁/c with four formula units in the unit cell. In the cations short PN distances of 159.7 pm and short AsN distances of 172.7 pm are to be found along with PNAs bond angles of 135.8°. With acetonitrile they react in the presence of potassium hydride forming the acetonitrile derivatives (Ph₃As)₂CCN]X. The crystal structure analysis of the bromide shows an ionic structure with a linear CCN group of the cation and an As–C–As bond angle of 126.9°. (Ph₃As)₂CCN]Br reacts with tin tetrabromide to form the complex (Ph₃As)₂CCN(SnBr₅)] with a zwitterionic structure and a bond angle CNSn of 144.0°.