Ru(II) complexes containing dihydro-1,1,3,3-tetramethyl-7,8-diazacyclopenta[1]phenanthren-2-ol ligand: Synthesis and their electrochemiluminescent characteristics

Abstract

A series of new ruthenium(II) complexes containing dihydro-1,1,3,3-tetramethyl-7,8-diazacyclopenta[1]phenanthren-2-ol (DTDP-OH) ligand, such as [Ru(DTDP-OH) n (L) 3− n ] 2+ (L = 2,2′-bipyridyl (bpy), o-phenanthroline ( o-phen), 2,2′-bipyridine-4,4′-dicarboaldehyde (bpy-(CHO) 2), 1,3-dihydro-1,1,3,3-tetramethyl-7,8-diazacyclopenta[1]phenanthren-2-one(DTDP), n = 1, 2, 3) were synthesized and their electrochemical and photophysical properties were studied. The synthesized Ru(II) complexes containing the DTDP-OH ligand showed strong MLCT absorptions at 420–487 nm. All the synthesized Ru(II) complexes containing the DTDP-OH ligand exhibited more intensive ECL emissions than the well-known [Ru( o-phen) 3] 2+ does. In particular, the ECL intensities of [Ru(DTDP-OH) 2( o-phen)] 2+ and [Ru(DTDP-OH) 2(bpy-(CHO) 2)] 2+ were observed to be more than 2-fold greater than that of [Ru( o-phen) 3] 2+.