Photoinduced energy transfer in multichromophores based on planar Pt–bipyridine–acetylide and octahedral Ru–bipyridine centres

Abstract

In bi- and trimetallic Pt-bipyridine-acetylide/Ru-bipyridine complexes the intermetallic Pt-Ru distance is approximately 9 è, and complete Pt-->Ru energy transfer is observed with sensitization of the Ru-based luminescence.

Switching of excited states in cyclometalated platinum complexes incorporating pyridyl-acetylide ligands (Pt–CC–py): a combined experimental and theoretical study

“…The room-temperature emission spectrum of complex 2 (CH 3 CN solution) exhibits structurally unresolved bands with a maximum at 570 nm and an emission quantum efficiency of the order of 6%. In accordance with previous studies, 9,[14][15][16][17][18][19][20] this emission is assigned to 3 MLCT excited states to which 3 L 0 LCT states may also contribute. The emission energy of 2 is blue-shifted when compared to that of [Pt( t Bu 2 -C^N^N)-(CRCPh)] 1 (l em = 588 nm, CH 3 CN solution).…”

“…[8][9][10][11][12][13] The ability to vary the ancillary ligand X is an elegant strategy to induce structural modification of the [(C^N^N)PtX] complexes and to tune their photophysical properties. In these series, acetylide derivatives 9,[14][15][16][17][18][19][20] are of special interest, not only because the strong-field nature of the acetylide ligand can help to augment the emission quantum yield, but also due to the facility with which functionalized terminal aryl-alkynes can be accessed, opening a way to new systems containing a diversity of host receptors. [21][22][23][24][25][26][27][28][29][30][31] The more electron-withdrawing the group on the phenyl acetylide ligand, the higher the emission energy.…”

Coordinating Tectons: Bipyridyl-Terminated Group 8 Alkynyl Complexes

“…Cyclic voltammetry of the complex 5 also shows a single irreversible reduction process at −1090 mV, interpreted as a reduction of the bipyridyl moiety, a redox process presumably outside the voltammetric windows investigated for complexes 3 and 4 but anodically shifted into the observable region on coordination of the electron-withdrawing palladium center. A similar redox process at −1170 to −1340 MV has been ascribed to the bipyridyl alkynyl moiety in a series of heterobimetallic ruthenium−platinum complexes derived from [(dtbpy)Pt(C 2 bpy) 2 ], and similarly for [PdCl 2 (bpy)] and analogues …”

“…While complex 9 is best compared to the reported complexes containing the [Ru(bpy) 2 (C 2 bpy)] 2+ moiety from reaction of [(L)Pt(C 2 bpy) n ] with [RuCl 2 (bpy) 2 ], , there is no structural information relevant to the complex of interest. Thus when compared to other [Ru(bpy) 2 (5-R-bpy)] 2+ cations structurally characterized that are substituted at the 5-position on one of the bipyridyl ligands, e.g., [Ru(bpy) 2 (5-pyrene - bpy)] 2+ , there is very little that is remarkable about the geometry of either complex.…”

Efficient light harvesting via sequential two-step energy accumulation using a Ru–Re5 multinuclear complex incorporated into periodic mesoporous organosilica

“…[26][27][28][29] In addition, polymers with many emissive transition metal complexes or organic chromophores as pendants have been studied. [30][31][32][33][34] As an adroit example, Gust et al 35 reported that energy transfer proceeded in a widely light-absorbing molecule called a "molecular hexad" that consisted of three different types of light absorbers (each in the same quantity) and an electron acceptor (fullerene). Efficient and directional energy transfer ultimately proceeded to one of the absorbers (ZnTPP), then charge separation occurred between the excited ZnTPP as a donor and fullerene as an acceptor.…”