Syntheses and Luminescent Behavior of π-Extended Ru(bpy)_3~(2+) Derivatives through Triple Hydrogen Bonds as an Organic-inorganic Hybridized Material

摘要

Two new bipyridine derivative ligands with an extended n 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.