Structure of poly-(N-vinylpyrrolidone) complexes with samarium diphthalocyanine in aqueous solutions

Complexes of poly-N-vinylpyrrolidone with the "sandwich" compound of samari um diphthalocyanine were studied in aqueous solutions using viscometry, ele ctronic absorption spectroscopy, dynamic light scattering, and neutron diff raction methods. The association of molecules of the complex into a structu re stable at room temperature was found. The size of associates depends on the polymer concentration: large associates with a hydrodynamic diameter of d(a) similar to 200 nm prevail in dilute solutions (c similar to 0.1 wt %) , while at c = 3 wt %, which is close to the threshold of coil overlapping in D2O, the radius of inertia of the associate R-GA similar to 5 nm) is of the same order as the radius of poly-N- vinylpyrrolidone macromolecules.