Syntheses and Luminescent Behavior of π-Extended [Ru(bpy)3]2+ Derivatives through Triple Hydrogen Bonds as an Organic-Inorganic Hybridized Material
Two new bipyridine derivative ligands with an extended π electron system and a triple hydrogen bond group, 2,4-diaminopyrimido[5,6-b]dipyrido[2,3-f:2’,3’-h]quinoxaline (DAPQ) and 2,4(1H,3H)-pyrimidinedion[5,6-b]dipyrido[2,3-f:2’3’-h]quinoxaline (PDPQ), were synthesized in order to construct high-performance Ru(II) complexes. The two Ru(II) complexes composed of dapq or pdpq and two 2,2’-bipyridine (BPY) ligands showed characteristic luminescent spectra with a peak maximum at ca. 610 nm. The octahedral Ru(II) complexes with a D-A-D (D: proton donor; A: proton acceptor) type triple hydrogen bond indicated intense luminescence in comparison with the corresponding Ru(II) complex composed of three BPY ligands. When the triple hydrogen bond was formed with a Co(III) complex with the D-A-D type hydrogen bonding group, the luminescence was quenched. This result was explained in terms of an energy transfer from an excited Ru(II) complex to the Co(III) complex.
Masayuki Nogami, Riguang Jin, Toshihiro Kasuga and Wantai Yang
T. Ozawa et al., "Syntheses and Luminescent Behavior of π-Extended [Ru(bpy)3]2+ Derivatives through Triple Hydrogen Bonds as an Organic-Inorganic Hybridized Material", Advanced Materials Research, Vols. 11-12, pp. 277-280, 2006