THE STRUCTURE OF AMORPHOUS PT-URIDINE BLUE NITRATE BY WAXS AND SAXS

Amorphous Pt-uridine blue nitrate was studied in the solid state by th e wide angle X-ray scattering method and in aqueous solution by the sm all angle X-ray scattering method. The radial distribution function (R DF) closely resembled that of Pt-uridine blue sulfate. It is proposed that both are mixtures of Pt(II)(2) and Pt(III)(2) units with Pt-Pt di stance of 3.0 and 2.6 Angstrom, respectively. However, the RDF for Pt- uridine blue nitrate could also be reproduced quite well with a mononu clear model, where the Pt-ONO2 distance is about 2.6 Angstrom. In aque ous solution Pt-uridine blue nitrate forms aggregates whose radius of gyration in low concentrations is about 8.4 +/- 0.7 Angstrom.