REACTIONS OF GAS-PHASE ATOMIC METAL-IONS WITH THE MACROCYCLIC LIGAND TRIBENZOCYCLOTRIYNE

Reactions of 22 atomic metal cations with the macrocyclic molecule tri benzocyclotriyne (TBC) were studied in the gas phase in the Fourier-tr ansform ion cyclotron resonance spectrometer. Most of the ions underwe nt association with TBC with good collisional efficiency to give M(TBC )+, with the exceptions of Zn+ and Au+, for which the highly exothermi c charge-transfer reaction dominated, and Cs+, which was unreactive. M ost of the M(TBC)+ ions attached a second ligand to give M(TBC)2+, pre sumably the sandwich complex. Cases for which sandwich formation was s low or negligible included several late first-row transition metal ion s which probably insert into the TBC cavity, and several other ions (K +, Al+, Pb+) which apparently have poor electronic interaction with th e ligand. Periodic trends for both complexation reactions are discusse d, and a rationale is advanced for the surprising inefficiency of exot hermic charge transfer in most cases.