Electrical resistivity and ESCA studies on neutral poly(alkylbenzimidazoles), their salts, and complexes

A series of metal and acid salts having poly(alkylbenzimidazoles) as the parent ligand were synthesized. The room‐temperature electrical resistivity of the parent and the salts was measured. Values for the dc electrical resistivity varied from ∼1 × 10 13 ohm.cm for the neutral polymers to ∼1 × 10 6 ohm·cm for the acid conjugate formed by reaction with HCl. Unexpectedly, changes in resistivity did not correlate with acid strength as measured by us but could be roughly correlated with the molar volume of the corresponding acid or metal salt. The nature of the complexes was elucidated using the ESCA technique. The electron core levels of nitrogen, chlorine, and the various metals were examined. The observed photoelectron spectra indicated the formation of polybenzimidazole/acid and polybenzimidazole/metal salts. In addition, one was able to conclude that the complexes of Co and Ni were high spin, thus ruling out a planar geometry for the Ni(II) complex.