Amphiphilic Ruthenium(II) Terpyridine Sensitizers with Long Alkyl Chain Substituted β-Diketonato Ligands: An Efficient Coadsorbent-Free Dye-Sensitized Solar Cells

Table 1

Absorption, luminescence, and electrochemical properties of the ruthenium complexes.

Sensitizer	Absorption,^aλ max/nm (ε/10^3 M^-1 cm^-1)	Emission λ max ^b/nm		Emission τ ^b/ns		E (Ru^3+/2+)^c / versus SCE	E* (Ru^3+/2+)^d/ versus SCE
		298 K	77 K	298 K	77 K
A1	280 (27.6), 331 (22.7), 422 (14.7), 606 (7.0)	940	905	16	160	+0.68	−0.90
A2	280 (28.2), 331 (23.1), 418 (13.6), 605 (7.1)	945	900	15	214	+0.70	−0.95
A3	280 (30.0), 331 (23.6), 422 (14.7), 606 (7.0)	950	910	16	152	+0.70	−0.95

^aMeasured in 4 : 1 v/v ethanol : methanol at room temperature.
^bThe emission spectra and emission lifetime were obtained by exciting into the lowest MLCT band in 4 : 1 v/v ethanol : methanol.
^cHalf-wave potentials assigned to the Ru^3+/2+ couple for ruthenium sensitizers bound to nanocrystalline TiO₂ film, measured in 0.1 M LiClO₄ acetonitrile solution.
^dCalculated from E* (Ru^3+/2+) = E (Ru^3+/2+) − E ^0-0; E ^0-0 values were estimated from the 5% intensity level of the emission spectra at 77 K.