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Gas-phase experiments using collision-induced dissociation in an ion trap mass spectrometer have been used in combination with density functional theory (DFT) calculations (at the B3LYP/SDD6-31+G(d) level of theory) to examine the competition between decarboxylation and loss of a coordinated acetonitrile in the unimolecular fragmentation reactions of the silver acetate and silver propiolate complexes, [RCO2Ag2 (CH3CN) n]+ (where R = CH3 and CH3C=C; n = 1 and 2), introduced into the gas-phase via electrospray ionisation. When R = CH[sub 3], loss of acetonitrile is the sole reaction channel observed for both complexes (n = 1 and 2), consistent with DFT calculations, which highlight that the barriers for decarboxylation 2.18 eV (n = 2) and 1.96 eV (n = 1) are greater than the binding energies of the coordinated acetonitriles (1.60 eV for n = 2; 1.64 eV for n = 1). In contrast, when R = CH3C=C, decarboxylation is the main fragmentation pathway observed for both complexes (n = 1 and 2), with loss of acetonitrile only being a minor product channel. This is consistent with DFT calculations, which reveal that the barriers for decarboxylation are 1.17 eV (n = 2) and 1.16 eV (n = 1), which are both below the binding energies of the coordinated acetonitriles (1.55 eV for n = 2; 1.56 eV for n = 1). The barrier for decarboxylation of [CH3C=CCO2Ag2]+ is 1.22 eV, which is less than the 2.06 eV reported for decarboxylation of [CH3CO2Ag2]+ (Al Sharif et al. Organometallics, 2013, 32, 5416). The observed ease of decarboxylation of silver propiolate complexes in the gas-phase is consistent with the recently reported use of silver salts in metal catalysed decarboxylative C-C and C-X bond forming reactions of propiolic acids. Fragmentation of the complexes [RCO2Ag2 (CH3CN)n]+ (n = 1 and 2) is dictated by the R group. Decarboxylation is preferred over loss of a coordinated acetonitrile for R = CH[sub 3]C=C, but ligand loss is the sole pathway when R = CH3. [ABSTRACT FROM AUTHOR]