Optical and Infrared Spectroelectrochemical Studies of CN-Substituted Bipyridyl Complexes of Ruthenium(II).
Optical and Infrared Spectroelectrochemical Studies of CN-Substituted Bipyridyl Complexes of Ruthenium(II).
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CN 取代的钌 (II) 联吡啶配合物的光学和红外光谱电化学研究。
DOI:
10.1021/acs.inorgchem.0c03579
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发表时间:
2021
影响因子:
4.6
通讯作者:
Taylor JO
中科院分区:
文献类型:
--
作者:
Taylor JO
Ruthenium(II) polypyridyl complexes [Ru(CN-Me-bpy)x(bpy)3–x]2+(CN-Me-bpy = 4,4′-dicyano-5,5′-dimethyl-2,2′-bipyridine, bpy = 2,2′-bipyridine, andx= 1–3, abbreviated as12+,22+, and32+) undergo four (12+) or five (22+and32+) successive one-electron reduction steps between −1.3 and −2.75 V versus ferrocenium/ferrocene (Fc+/Fc) in tetrahydrofuran. The CN-Me-bpy ligands are reduced first, with successive one-electron reductions in22+and32+being separated by 150–210 mV; reduction of the unsubstituted bpy ligand in12+and22+occurs only when all CN-Me-bpy ligands have been converted to their radical anions. Absorption spectra of the first three reduction products of each complex were measured across the UV, visible, near-IR (NIR), and mid-IR regions and interpreted with the help of density functional theory calculations. Reduction of the CN-Me-bpy ligand shifts the ν(C≡N) IR band by ca. −45 cm–1, enhances its intensity ∼35 times, and splits the symmetrical and antisymmetrical modes. Semireduced complexes containing two and three CN-derivatized ligands2+,3+, and30show distinct ν(C≡N) features due to the presence of both CN-Me-bpy and CN-Me-bpy•–, confirming that each reduction is localized on a single ligand. NIR spectra of10,1–, and2–exhibit a prominent band attributable to the CN-Me-bpy•–moiety between 6000 and 7500 cm–1, whereas bpy•–-based absorption occurs between 4500 and 6000 cm–1; complexes2+,3+, and30also exhibit a band at ca. 3300 cm–1due to a CN-Me-bpy•–→ CN-Me-bpy interligand charge-transfer transition. In the UV–vis region, the decrease of π → π* intraligand bands of the neutral ligands and the emergence of the corresponding bands of the radical anions are most diagnostic. The first reduction product of12+is spectroscopically similar to the lowest triplet metal-to-ligand charge-transfer excited state, which shows pronounced NIR absorption, and its ν(C≡N) IR band is shifted by −38 cm–1and 5–7-fold-enhanced relative to the ground state.
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DOI:
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发表时间:
2017
期刊:
影响因子:
--
作者:
Laura M. Kiefer;K. Kubarych
通讯作者:
K. Kubarych
DOI:
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发表时间:
1995
期刊:
影响因子:
--
作者:
S. Záliš;M. Krejcik;V. Drchal;A. Vlček
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A. Vlček
DOI:
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发表时间:
1985
期刊:
影响因子:
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作者:
R. Amos
通讯作者:
R. Amos
DOI:
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发表时间:
2006
期刊:
影响因子:
--
作者:
R. C. Rocha;A. Shreve
通讯作者:
A. Shreve
DOI:
--
发表时间:
1987
期刊:
影响因子:
--
作者:
B. Gaš;J. Klima;S. Záliš;A. Vlc̆ek
通讯作者:
A. Vlc̆ek