sp–sp3 Coupling reactions of alkynylsilver cations, RC&≡CAg2 (R = Me and Ph) with allyliodide

Abstract

Alkynylsilver cations, RC&≡CAg2+ (where R = Me and Ph) have been prepared in the gas phase using multistage mass spectrometry experiments in a quadrupole ion trap mass spectrometer. Two methods were used: (i) electrospray ionisation (ESI) of a mixture of AgNO3 (in MeOH/H2O/acetic acid) and the alkyne carboxylic acid to yield the appropriate silver acetylide cations RC&≡CAg2+, via a facile decarboxylation of the RC&≡CCO2Ag2+ precursor; (ii) ESI of silver acetylides, RC&≡CAg, which yields a cluster of the type, [(RC&≡CAg)12Ag2Cl]+. Regardless of the method of preparation, these alkynylsilver cations, RC&≡CAg2+, undergo ion-molecule reactions with allyliodide to yield the ionic products Ag2I+ a..