Extended diruthenium sigma-alkynyl complexes and attenuation of electronic coupling
Abstract
Research on carbon rich molecules containing carbon-carbon triple bonds attract intense interests from chemists, biologists and material scientists over the past several decades. The organometallic oligo/polyynes are superior to the organic analogs due to the introduction of transition metal centers which could bring in various improved physical properties. They have promising applications in luminescent devices, field effect transistors, semiconductors, solar cells and molecular electronic devices. My research focuses on the development of extended diruthenium σ-alkynyl species as promising building blocks for organometallic molecular wires, which can mediate charge transfer. Efforts of synthesis and detailed characterizations were devoted on three different types of diruthenium carbon-rich compounds. First, polyyn-diyls (-(C≡C) n-) capped by two σ-bonded Ru2(DiMeOap)4 units (DiMeOap is 2-(3, 5-dimethoxyanilino)pyridinate) were prepared with n up to 10. Strong electronic coupling was inferred from their voltammetric data and rough estimation of the small electronic coupling attenuation constants suggests polyyn-diyl bridges are efficient in mediating charge transfer. The second series of compounds, FcC2n-Ru2(Y-DMBA) 4-C2nFc (n =3, 4; Y-DMBA is N,N'-dimethylbenzamidinate and its MeO-substituent), were designed to probe the efficiency of charge transfer across the Ru2 unit. Voltammetric study revealed sizable separations of step-wise Fc-oxidations and hence efficient charge transfer between two Fc across Ru2 unit over a span of 27 Å. Additional effort was directed towards modulation of charge transfer property through covalent modifications of polyyn-diyl chain with Co2(CO)4dppm and tetracyanoethylene, respectively. The impact of modulation on electronic couplings between two Ru2 moieties was successfully assessed through voltammetric study.^
Degree
Ph.D.
Advisors
Tong Ren, Purdue University.
Subject Area
Chemistry, Inorganic
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