Fabrication of polymer organized thin films containing ruthenium complexes

Polyion complex Langmuir-Blodgett (LB) films containing Ru(dpphen)₃²⁺ (dpphen = 4,7-diphenyl-1,10-phenanthroline) probe (Rudpphen) were prepared by spreading a mixed chloroform solution of N-dodecylacrylamide (DDA)-N-acryloxysuccinimide (SuOA) copolymer and Ru(dpphen)₃Cl₂, onto the water subphase at pH = 11. The SuOA groups undergo a hydrolysis at pH = 11 yielding the acrylate anion, which forms an ion-complex with Ru(dpphen)₃²⁺ in the monolayer. It was found that Ru(dpphen)₃²⁺ is located in the hydrophobic portion of the monolayer at the air/water interface. The monolayers of p(DDA/Rudpphen) could be successfully transferred on a quartz substrate with less than 14 mol% Ru(dpphen)₃²⁺ content. The UV-vis spectroscopy and X-ray diffraction confirmed that the Ru(dpphen)₃²⁺ molecules were densely packed and uniformly distributed in the polyion complex LB films. The properties of p(DDA/Rudpphen) monolayer and LB films were compared with p(DDA/Rubpy) LB films (bpy = 2,2′-bipyridine), which have been previously reported. The luminescence quenching of Ru(dpphen)₃²⁺ by oxygen was also discussed.