TY - JOUR
T1 - Photoinduced four- and six-electron reduction of mononuclear ruthenium complexes having NAD+ analogous ligands
AU - Fukushima, Takashi
AU - Wada, Tohru
AU - Ohtsu, Hideki
AU - Tanaka, Koji
PY - 2010/12/28
Y1 - 2010/12/28
N2 - The ruthenium complexes [Ru(bpy)(pbn)2](PF6) 2 ([2]2+; bpy = 2,2′-bipyridine, pbn = 2-(2-pyridyl)benzo[b]-1,5-naphthyridine) and [Ru(pbn)3](PF 6)2 ([3]2+) were synthesized. Photoirradiation (λ > 420 nm) of [2]2+ and [3]2+ in CH 3CN/triethanolamine (TEOA) brought about proton coupled four- and six-electron reduction of the complexes to produce [Ru(bpy)(pbnH 2)2](PF6)2 ([2·H 4]2+; pbnH2 = 5,10-dihydro-2-(2-pyridyl) benzo[b]-1,5-naphthyridine) and [Ru(pbnH2)3](PF 6)2 ([3·H6]2+), respectively. The photoexcited [RuIII(bpy)(pbn-)(pbnH 2)]2+ intermediate is quenched by intermolecular electron transfer from TEOA to RuIII, while intramolecular transfer from pbnH2 to RuIII is negligible. As a result, novel photochemical four- and six-electron reduction of [2]2+ and [3] 2+ is achieved through repetition of the two-electron reduction of the Ru-pbn group. The high efficiency photochemical two-, four- and six-electron reductions of [Ru(bpy)2(pbn)]2+ ([1]2+), [2]2+ and [3]2+, respectively, by taking advantage of proton coupled two electron reduction of NAD+ analogous type ligands such as pbn opens a general pathway for multi-electron reduction of metal complexes via illumination with visible light.
AB - The ruthenium complexes [Ru(bpy)(pbn)2](PF6) 2 ([2]2+; bpy = 2,2′-bipyridine, pbn = 2-(2-pyridyl)benzo[b]-1,5-naphthyridine) and [Ru(pbn)3](PF 6)2 ([3]2+) were synthesized. Photoirradiation (λ > 420 nm) of [2]2+ and [3]2+ in CH 3CN/triethanolamine (TEOA) brought about proton coupled four- and six-electron reduction of the complexes to produce [Ru(bpy)(pbnH 2)2](PF6)2 ([2·H 4]2+; pbnH2 = 5,10-dihydro-2-(2-pyridyl) benzo[b]-1,5-naphthyridine) and [Ru(pbnH2)3](PF 6)2 ([3·H6]2+), respectively. The photoexcited [RuIII(bpy)(pbn-)(pbnH 2)]2+ intermediate is quenched by intermolecular electron transfer from TEOA to RuIII, while intramolecular transfer from pbnH2 to RuIII is negligible. As a result, novel photochemical four- and six-electron reduction of [2]2+ and [3] 2+ is achieved through repetition of the two-electron reduction of the Ru-pbn group. The high efficiency photochemical two-, four- and six-electron reductions of [Ru(bpy)2(pbn)]2+ ([1]2+), [2]2+ and [3]2+, respectively, by taking advantage of proton coupled two electron reduction of NAD+ analogous type ligands such as pbn opens a general pathway for multi-electron reduction of metal complexes via illumination with visible light.
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U2 - 10.1039/c0dt00504e
DO - 10.1039/c0dt00504e
M3 - Article
C2 - 20830398
AN - SCOPUS:78649716555
SN - 1477-9226
VL - 39
SP - 11526
EP - 11534
JO - Dalton Transactions
JF - Dalton Transactions
IS - 48
ER -