Formation and reactions of the 1, 8-naphthyridine (napy) ligated geminally dimetallated phenyl complexes [(napy)Cu 2 (Ph)] + , [(napy)Ag 2 (Ph)] + and [(napy)CuAg(Ph)] .

Gas-phase ion trap mass spectrometry experiments and density functional theory calculations have been used to examine the routes to the formation of the 1,8-naphthyridine (napy) ligated geminally dimetallated phenyl complexes [(napy)Cu2 (Ph)]+ , [(napy)Ag2 (Ph)]+ and [(napy)CuAg(Ph)]+ via extrusion of CO2 or SO2 under collision-induced dissociation conditions from their corresponding precursor complexes [(napy)Cu2 (O2 CPh)]+ , [(napy)Ag2 (O2 CPh)]+ , [(napy)CuAg(O2 CPh)]+ and [(napy)Cu2 (O2 SPh)]+ , [(napy)Ag2 (O2 SPh)]+ , [(napy)CuAg(O2 SPh)]+ . Desulfination was found to be more facile than decarboxylation. Density functional theory calculations reveal that extrusion proceeds via two transition states: TS1 enables isomerization of the O, O-bridged benzoate to its O-bound form; TS2 involves extrusion of CO2 or SO2 with the concomitant formation of the organometallic cation and has the highest barrier. Of all the organometallic cations, only [(napy)Cu2 (Ph)]+ reacts with water via hydrolysis to give [(napy)Cu2 (OH)]+ , consistent with density functional theory calculations which show that hydrolysis proceeds via the initial formation of the adduct [(napy)Cu2 (Ph)(H2 O)]+ which then proceeds via TS3 in which the coordinated H2 O is deprotonated by the coordinated phenyl anion to give the product complex [(napy)Cu2 (OH)(C6 H6 )]+ , which then loses benzene.