TY - JOUR
T1 - Synthesis and Characterization of a RuPt-Based Photo-Hydrogen-Evolving Molecular Device Tethered to a Single Viologen Acceptor
AU - Miyaji, Masayuki
AU - Kitamoto, Kyoji
AU - Ozawa, Hironobu
AU - Sakai, Ken
N1 - Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2017/3/3
Y1 - 2017/3/3
N2 - A dinuclear RuIIPtII complex tethered to a methyl viologen (MV2+) unit {RuPt-MV2+; [RuII(bpy)2{phen-bpy(MV2+)}PtIICl2]4+, bpy = 2,2′-bipyridine, phen = 5-amino-1,10-phenanthroline} has been synthesized to investigate the effect of tethering a single pendant MV2+ acceptor on its photo-hydrogen-evolving (PHE) activity. Upon photoirradiation of RuPt-MV2+ in the presence of EDTA as a sacrificial electron donor, the one-electron-reduced species of RuPt-MV2+ {i.e., [RuII(bpy)2{phen-bpy(MV+·)}PtIICl2]3+} is generated as a major photoproduct by intramolecular electron transfer (IET) from the 3MLCT excited state of the [RuII(bpy)2(phen)]2+ unit to the MV2+ unit, followed by subsequent reduction of the [RuIII(bpy)2(phen)]3+ unit by EDTA. Although RuPt-MV2+ shows PHE activity in the presence of EDTA, the estimated turnover number (0.4) is smaller than that for the parent RuIIPtII system, which has no MV2+ tether. The relatively small driving force (0.08 eV) for the IET from the 3MLCT excited state of the [RuII(bpy)2(phen)]2+ unit to the PtIICl2(bpy) unit, which leads to the H2 formation, has been judged to be the major cause of the exceptionally low PHE activity observed for the present system.
AB - A dinuclear RuIIPtII complex tethered to a methyl viologen (MV2+) unit {RuPt-MV2+; [RuII(bpy)2{phen-bpy(MV2+)}PtIICl2]4+, bpy = 2,2′-bipyridine, phen = 5-amino-1,10-phenanthroline} has been synthesized to investigate the effect of tethering a single pendant MV2+ acceptor on its photo-hydrogen-evolving (PHE) activity. Upon photoirradiation of RuPt-MV2+ in the presence of EDTA as a sacrificial electron donor, the one-electron-reduced species of RuPt-MV2+ {i.e., [RuII(bpy)2{phen-bpy(MV+·)}PtIICl2]3+} is generated as a major photoproduct by intramolecular electron transfer (IET) from the 3MLCT excited state of the [RuII(bpy)2(phen)]2+ unit to the MV2+ unit, followed by subsequent reduction of the [RuIII(bpy)2(phen)]3+ unit by EDTA. Although RuPt-MV2+ shows PHE activity in the presence of EDTA, the estimated turnover number (0.4) is smaller than that for the parent RuIIPtII system, which has no MV2+ tether. The relatively small driving force (0.08 eV) for the IET from the 3MLCT excited state of the [RuII(bpy)2(phen)]2+ unit to the PtIICl2(bpy) unit, which leads to the H2 formation, has been judged to be the major cause of the exceptionally low PHE activity observed for the present system.
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U2 - 10.1002/ejic.201601346
DO - 10.1002/ejic.201601346
M3 - Article
AN - SCOPUS:85014924644
VL - 2017
SP - 1237
EP - 1244
JO - Berichte der deutschen chemischen Gesellschaft
JF - Berichte der deutschen chemischen Gesellschaft
SN - 0365-9496
IS - 9
ER -