RESUMEN
The supramolecular dimerization of a ruthenium polypyridyl precursor of a well-developed family of hydrogen-evolving photocatalysts via π-π interactions of the polyheteroaromatic bridging ligand was quantified with concentration-dependent 1 H-NMR spectroscopy. The data sets were analyzed with different calculation and fit methods. A comparison between the results of direct calculation and linear and nonlinear approaches showed that the application of a global nonlinear fit procedure yields the best results. The presented methods are also applicable for dimerization processes in the solution of other molecular moieties.
Asunto(s)
Fármacos Fotosensibilizantes , Rutenio , Rutenio/química , Espectroscopía de Resonancia Magnética/métodos , Ligandos , DimerizaciónRESUMEN
1,10-Phenanthroline-5,6-diaryldiazadienes are key structures for the development of novel heterodinuclear photocatalysts and for the construction of extended heterocycles of potential biological use. Herein, the first examples of this compound family are presented together with a wide range of initial reactivity studies. Synthetic strategies are presented to access the two first derivatives of the ligand and to accomplish subsequent metal coordination to the phenanthroline sphere.
Asunto(s)
Alquenos/química , Compuestos Aza/química , Complejos de Coordinación/química , Iridio/química , Fenantrolinas/química , Alquenos/síntesis química , Compuestos Aza/síntesis química , Complejos de Coordinación/síntesis química , Ligandos , Modelos Moleculares , Fenantrolinas/síntesis químicaRESUMEN
The effects of the planar aromatic organic molecules anthracene and pyrene on the catalytic performance of the intramolecular hydrogen evolving photocatalyst [Ru(tbbpy)2(tpphz)PdCl2](PF6)2 functioning as a photocatalytic dyad have been studied. (1)H-NMR studies on [Ru(tbbpy)2(tpphz)PdCl2](PF6)2 and [Ru(tbbpy)2(tpphz)](PF6)2 show a pronounced interaction of pyrene with the ruthenium complexes due to π-π-interactions. The solid state structure of [Ru(tbbpy)2(tpphz)PdCl2]2[Mo8O24] shows a pronounced π-π-stacking of the polyaromatic ligands. In addition, dimerization constants for the complexes and association constants between the complexes and pyrene were determined. Studies on the photocatalytic hydrogen production show a decreased induction phase and increased turn over frequencies during the initial phase of the catalysis in the presence of anthracene and pyrene utilising the catalyst [Ru(tbbpy)2(tpphz)PdCl2](PF6)2 irrespective of the nature of the polycyclic aromatic hydrocarbon.