Structural characteristics of amorphous K-Bi citrate (De-Nol) and its aqueous solutions from EXAFS spectra.

EXAFS (Extended X-ray Absorption Fine Structure) spectra of an amorphous solid Bi complex with citrate (known as De-Nol) and its aqueous solutions in a wide concentration range are measured. For the solutions good agreement is revealed between their structural parameters and the averaged interatomic distances and coordination numbers of the crystalline polymeric bismuth citrate compound composed of 12-nuclear Bi clusters based on the structure BiO. So, it is found that droplets of the colloidal solution have a core structure close to the solid BiO cluster structure.