Evaluation of 1H‐NMR Spectroscopy‐Based Quantification Methods of the Supramolecular Aggregation of a Molecular Photosensitizer^†

Abstract

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 1H‐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.

Prediction of strong solvatochromism in a molecular photocatalyst

“…11 The catalytic efficiency of the lightdriven hydrogen evolution reaction of RuPtI 2 and the related RuPdCl 2 is strongly dependent on several factors such as the nature of the sacrificial electron donor 12 and supramolecular aggregation phenomena. [13][14][15] The interaction with polyaromatic supramolecular activators via π − π bonding with the bridging ligand led to a reduction in the induction phase and an improved initial turnover frequency (TOF) and turnover number (TON) for RuPdCl 2 . 13 The nature of the applied solvent mixtures has a profound effect on the attainable catalytic activity.…”

Prediction of Strong Solvatochromism in a Molecular Photocatalyst**

“…[11] The catalytic efficiency of the lightdriven hydrogen evolution reaction of RuPtI 2 and the related RuPdCl 2 is strongly dependent on several factors such as the nature of the sacrificial electron donor [12] and supramolecular aggregation phenomena. [13][14][15] The interaction with polyaromatic supramolecular activators via p-p bonding with the bridging ligand led to a reduction in the induction phase and an improved initial turnover frequency (TOF) and turnover number (TON) for RuPdCl 2 . [13] The nature of the applied solvent mixtures has a profound effect on the attainable catalytic activity.…”

“…The recently established novel active repair mechanism for this catalyst leads to a boost in attainable catalytic activity with triethylamine (TEA) as electron donor and acetonitrile water mixtures as solvents [11] . The catalytic efficiency of the light‐driven hydrogen evolution reaction of RuPtI 2 and the related RuPdCl 2 is strongly dependent on several factors such as the nature of the sacrificial electron donor [12] and supramolecular aggregation phenomena [13–15] . The interaction with polyaromatic supramolecular activators via $${\pi }$$ ‐$${\pi }$$ bonding with the bridging ligand led to a reduction in the induction phase and an improved initial turnover frequency (TOF) and turnover number (TON) for RuPdCl 2 [13] .…”