the effect of dye density on the efficiency of photosensitization of tio2 films light-harvesting by phenothiazine-labelled dendritic ruthenium complexes染料浓度的影响二氧化钛光敏作用效率的电影聚光phenothiazine-labelled树突钌配合物.pdf

Molecules 2009, 14, 3851-3867; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article The Effect of Dye Density on the Efficiency of Photosensitization of TiO Films: Light-Harvesting by Phenothiazine-Labelled 2 Dendritic Ruthenium Complexes Marye Anne Fox 1,*, James K. Whitesell 1, Douglas Magde 1 and Lin-Yong Zhu 2 1 Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA; E-Mails: jkw@ (J.K.W.); dmagde@ (D.M.) 2 Institute of Photographic Chemistry, Chinese Academy of Sciences, Beijing 100101, China; E-Mail: linyongzhu@ (L.-Y.Z.) * Author to whom correspondence should be addressed; E-Mail: mafox@. Received: 10 August 2009; in revised form: 14 September 2009 / Accepted: 22 September 2009 / Published: 28 September 2009 Abstract: A family of dendritic tris-bipyridyl ruthenium coordination complexes incorporating two or four carboxylate groups for binding to a TiO2 surface site and another dendritic linker between the metal complex and highly absorptive dyes were formulated as thin films on TiO2 coated glass. The family included phenothiazine-substituted dendrons of increasing structural complexity and higher optical density. The dye-loaded films were characterized by steady-state emission and absorption measurements and by kinetic studies of luminescence and transient absorption. Upon photoexcitation of the bound dyes, rapid electron injection into the metal oxide film was the dominan