Synthesis of Ruthenium Tris‐Diimine Photosensitizers Substituted by Four Methylphosphonate Anchoring Groups for Dye‐Sensitized Photoelectrochemical Cell Applications

Abstract

The design and synthesis of ruthenium tris‐diimine photosensitizers appropriately functionalized to be (i) anchored onto transparent conductive oxides (TCO) and (ii) covalently coupled with a water‐splitting catalyst represents an important target for solar fuel production in dye‐sensitized photoelectrochemical cells (DS‐PECs). In this study, two different synthetic routes to prepare heteroleptic [Ru(4,4′‐(CH2PO3Et2)2‐bpy)2(N^N)](PF6)2 complexes are evaluated, the scope and limitations of the organometallic pathway involving half‐sandwich η6‐arene ruthenium complexes as synthetic intermediates being especially studied. The spectroscopic and electrochemical characterization of a series of novel structures varying by the nature of the third diimine N^N ligand is reported.

In Vitro and In Vivo Biological Activity of Ruthenium 1,10-Phenanthroline-5,6-dione Arene Complexes

“…The new ruthenium complex JHOR10 was synthesized by the reaction of the Ru(II) precursor [Ru( p -cymene)Cl 2 ] 2 with a silver triflate in dichloromethane under the exclusion of light, followed by the addition of one equivalent of 1,10-phenanthroline-5,6-dione as shown in Scheme 1 . Complex JHOR11 has been already described and was prepared following the literature procedure [ 22 ] ( Scheme 1 ).…”

“…Reagents were purchased from commercial suppliers and used without further purification. Complexes JHOR10 and JHOR11 were prepared following the procedure described in the literature [ 22 ] by a reaction of the precursor [Ru( p -cymene)Cl 2 ] 2 with the halide abstractor silver triflate for JHOR10 and hexafluorofostate for JHOR11 [ 22 ], and next with the phendione ligand.…”

Hydrogen Production at a NiO Photocathode Based on a Ruthenium Dye–Cobalt Diimine Dioxime Catalyst Assembly: Insights from Advanced Spectroscopy and Post-operando Characterization

“…RuP 4 OEt -Co was synthesized by a copper-catalyzed azide-alkyne cycloaddition (CuAAC) coupling between the alkyne-substituted dye precursor RuP 4 OEt -EPIP and the azido-functionalized copper diimine dioxime complex, followed by a transmetallation step from Cu to Co, according to our previously reported procedures. , Acid–base titrations revealed that the dye precursor and the dyad were isolated under their imidazole-protonated form (Figure S2). Full synthetic details and characterizations are provided in the Supporting Information.…”

“…OEt -EPIP 39 and the azido-functionalized copper diimine dioxime complex, 42 followed by a transmetallation step from Cu to Co, according to our previously reported procedures. 19,20 Acid−base titrations revealed that the dye precursor and the dyad were isolated under their imidazole-protonated form (Figure S2).…”

“…38 This was further supported by transient absorption spectroelectrochemistry (TA-SEC) measurements recorded on the sensitized films at the operando potential, which allowed one to detect the formation of the Co I catalytically active species, albeit in very low yield, thus leading to the accumulation and degradation of the reduced dye on the surface of the film. 38 Here, we report on the synthesis and characterization of a novel dyad, RuP 4 -Co, featuring a ruthenium tris-diiimine photosensitizer substituted by four methylphosphonate anchoring groups, 39 covalently linked to the cobalt diimine dioxime H 2 -evolving catalyst. 40 Compared to the previous systems relying on the same catalyst, 19,20,22,37,38 significant improvements in the photocurrent density (4-to 6fold increase) and F.E.…”