Synthesis, characterization and photophysics of alkyne bridged bimetallic rhenium(I) and ruthenium(II) complexes

Binuclear ruthenium η6-arene complexes with tetradentate N,S-ligands containing the ortho-aminothiophenol motif

“…[14][15][16][17][18] Typical ligand systems bridging the two metals are bipyridines, terpyridines, polyacetaldehydes, ethynyl and para-substituted phenylene. [19][20][21][22][23][24][25][26][27][28][29][30][31][32] Mono-and binuclear Ru polypyridine complexes display electro-and photochemical properties associated with metalto-ligand charge transfer transitions. [33][34][35][36][37][38] Binuclear η 3 -allyland η 6 -arene Ru complexes showed a remarkable absorption in the visible region and electrochemical studies revealed interactions between the two metals, allowing for potential application as molecular wires.…”

Visible-Light Activation of the Bimetallic Chromophore–Catalyst Dyad: Analysis of Transient Intermediates and Reactivity toward Organic Sulfides

“…Chemical transformations of organic molecules driven by solar light did not receive due recognition from chemists in the 20th century, though Ciamician commented on its importance in the beginning of the century. Photocatalytic organic transformations using sunlight generally involve mild conditions for substrate activation, ideally light alone; this has attracted researchers to devise new photocatalytic systems in recent years. − Though Deronzier et al developed pioneering photocatalytic systems involving [Ru(bpy) 3 ] 2+ (bpy = 2,2′-bipyridine) for organic transformations in the 1980s, little attention has been paid to such processes in the past three decades. , However, the recent past has seen a surge of enormous interest in visible light-induced organic transformations particularly using ruthenium(II)–polypyridyl complexes as solar light absorbers. − The advantage with Ru(II) complexes is that they have strong absorption in the visible region and it is possible to tune the photophysical properties by changing the structure of the polypyridyl ligand. , Currently, photochemists have developed many ruthenium(II)–polypyridyl–catalyst binuclear dyads where both the photosensitizer and the catalyst fragments are part of the same molecule to perform light-induced redox processes. − In these supramolecular photocatalytic systems the catalytic part is activated by either electron transfer − or energy transfer processes. ,, It is important to mention here that the photosensitizer linked to electron acceptor/donor-mimicking photosystem II (PS II) is an attractive candidate for conversion of solar energy into chemical energy. − In this connection, we recently reported binuclear supramolecular models consisting of a ruthenium(II)– or rhenium(I)–polypyridyl moiety linked covalently with different metal ions including manganese to study the light-induced photophysical processes. − In order to develop systems similar to the PS II, we synthesized a Ru(II)–polypyridyl photosensitizer covalently linked with a methionine donor where a methionine radical could be formed by light-induced intramolecular electron transfer reaction . During the past decade, Hammarström, Sun, Åkermark, Styring, Aukauloo, and others have made great efforts to link Ru(II)–pol...…”