RELATIVE METAL-ION AFFINITIES OF ORGANIC NITRILES IN THE GAS-PHASE

The relative metal ion (Ni+ and Co+) affinities of 14 alkanenitriles, alkenenitriles and benzonitrile were estimated using Cooks' kinetic method in a fast atom bombardment mass spectrometer. The results are compared with proton affinities, affinities for other metal ions, two-ligand dissociation enthalpies and the dipole moments of the nitriles. The RCN-Co+ bond is found to be close to the RCN-Ni+ bond but weaker than the RCN-Al+ bond. The effective temperature (T) of the metal-bound dimer ions falls in the range 298 K < T < 400 K.