Several dendritic bridging ligands were designed and synthesized to develop more sensitive and efficient electrochemiluminescent (ECL) polynuclear Ru(II) complexes. Various types of novel two-armed, four-armed and six-armed tris(bipyridyl)ruthenium core dendrimers were synthesized by coordinating dendritic polybipyridyl ligands with Ru(II) complexes, and the effect of the ligand and the dendritic network on the ECL characteristics were studied. Their electrochemical redox potentials, UV, photoluminescence (PL), and relative ECL intensities were also investigated in detail. The synthesized metallodendrimers exhibited strong metal-to-ligand charge transfer (MLCT) absorption at 428-451 nm and emission at 591-601 nm. Most of the newly synthesized metallodendrimers showed enhanced ECL intensities compared to the reference complex, [Ru(o-phen)3](PF6)2. In particular, the ECL intensities of the six-armed heptanuclear ruthenium complexes were almost four times greater than that of [Ru(o-phen)3]2+. These metallodendrimers could be utilized as efficient ECL materials and light emitting devices.
Bibliographical noteFunding Information:
The financial supports from the RRC program of the Ministry of Commerce, Industry and Energy, from CBMH, and partly from Kwangwoon University in the year 2006 are gratefully acknowledged. S.H.Y also acknowledges the support of the BK 21 program of the Ministry of Education and Human Resources Development.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry