Tetranuclear Complexes Containing a Luminescent Ru₂M₂ Core [M = Cu^I, (allyl)Pd^II]: Synthesis, Structures and Electrochemical Properties

Abstract

The reaction between [(tbbpy) 2 Ru(tmbiH 2 )](PF 6 ) 2 (tbbpy = 4,4Ј-di-tert-butyl-2,2Ј-bipyridine; tmbiH 2 = 5,5Ј,6,6Ј-tetramethyl-2,2Ј-dibenzimidazole) and LiMe/CuI affords the tetranuclear complex 1 containing the dication [{(tbbpy) 2

Ultrafast Excited‐State Excitation Dynamics in a Quasi‐Two‐Dimensional Light‐Harvesting Antenna Based on Ruthenium(II) and Palladium(II) Chromophores

“…The luminescence occurs considerably red-shifted with respect to the excitation spectrum with a maximum at 650 nm and decays with a lifetime of 363 ns as determined from time-resolved luminescence measurements in THF. [37] In our experiments we used 500-nm pump pulses to excite the complex within the 1 MLCT band. Therefore, on the basis of the generally accepted description of the photophysics of Ru-polypyridine complexes we expect to observe a rapid formation of the long-lived 3 MLCT state.…”

“…[37,41,42] The complexes were dissolved in dichloromethane and acetone yielding an optical density of 1.5 in the 1-mm path-length cuvette, which was used for the time-resolved experiments. All solvents used in this study were HPLC grade as provided by the supplier (Aldrich).…”

“…The resulting lowest-lying excited state was found to have a lifetime of 363 ns by performing nanosecond time-resolved luminescence experiments in THF. [37] RuPd complex: Having discussed the ultrafast dynamic processes following initial photoexcitation of the [(tbbpy) 2 RuA C H T U N G T R E N N U N G (tmbiH 2 )] complex, forming the peripheral building blocks of the four-center complex [{(tbbpy) 2 Ru-…”

“…A detailed discussion of the structural features of Ru 2 Pd 2 can be found in the literature. [37] Thus, we consider the {[(tbbpy) 2 2 system to be an extremely interesting model of an inorganic antenna system with accessible reaction centers.…”

“…[57] The overall luminescence shows a maximum intensity at 658 nm and decays with a lifetime of 244 ns. [37] Figure 6B displays the TA spectrum of the Ru 2 Pd 2 complex taken 15 ps after photoexcitation of the system at 520 nm. The spectrum is dominated by a strong GSB in the region of the ground-state absorption.…”