1,5-Diamido-9,10-anthraquinone, a Centrosymmetric Redox-Active Bridge with Two Coupled b-Ketiminato Chelate Functions: Symmetric and Asymmetric Diruthenium Complexes
The dinuclear complexes (μ-H2L)Ru(bpy)22(ClO4)2 (3(ClO4)2), (μ-H2L)Ru(pap)22(ClO4)2 (4(ClO4)2), and the asym. (bpy)2Ru(m-H2L)Ru(pap)2(ClO4)2 (5(ClO4)2) were synthesized via the mononuclear species Ru(H3L)(bpy)2ClO4 (1ClO4) and Ru(H3L)(pap)2ClO4 (2ClO4), where H4L is the centrosym. 1,5-diamino-9,10-anthraquinone, bpy is 2,2'-bipyridine, and pap is 2-phenylazopyridine. Electrochem. of the structurally characterized 1ClO4, 2ClO4, 3(ClO4)2, 4(ClO4)2, and 5(ClO4)2 reveals multistep oxidn. and redn. processes, which were analyzed by EPR of paramagnetic intermediates and by UV-visible-NIR spectro-electrochem. With support by time-dependent d. functional theory (DFT) calcns. the redox processes could be assigned. Significant results include the dimetal/bridging ligand mixed spin distribution in 33+ vs. largely bridge-centered spin in 43+-a result of the presence of RuII-stabilizing pap coligands. In addn. to the metal/ligand alternative for electron transfer and spin location, the dinuclear systems allow for the observation of ligand/ligand and metal/metal site differentiation within the multistep redox series. DFT-supported EPR and NIR absorption spectroscopy of the latter case revealed class II mixed-valence behavior of the oxidized asym. system 53+ with about equal contributions from a radical bridge formulation. In comparison to the analogs with the deprotonated 1,4-diaminoanthraquinone isomer the centrosym. H2L2- bridge shows anodically shifted redox potentials and weaker electronic coupling between the chelate sites. on SciFinder(R)
%0 Journal Article
%1 Ansari.2016
%A Ansari, Mohd. Asif
%A Mandal, Abhishek
%A Paretzki, Alexa
%A Beyer, Katharina
%A Fiedler, Jan
%A Kaim, Wolfgang
%A Lahiri, Goutam Kumar.
%D 2016
%J Inorganic Chemistry
%K bipyridine complex complex;electrochem complex;ruthenium crystal diaminoanthracenedione dinuclear mononuclear phenyldiazenylpyridine prepn ruthenium spectroelectrochem structure
%N 11
%P 5655--5670
%R 10.1021/acs.inorgchem.6b00726
%T 1,5-Diamido-9,10-anthraquinone, a Centrosymmetric Redox-Active Bridge with Two Coupled b-Ketiminato Chelate Functions: Symmetric and Asymmetric Diruthenium Complexes
%V 55
%X The dinuclear complexes (μ-H2L)Ru(bpy)22(ClO4)2 (3(ClO4)2), (μ-H2L)Ru(pap)22(ClO4)2 (4(ClO4)2), and the asym. (bpy)2Ru(m-H2L)Ru(pap)2(ClO4)2 (5(ClO4)2) were synthesized via the mononuclear species Ru(H3L)(bpy)2ClO4 (1ClO4) and Ru(H3L)(pap)2ClO4 (2ClO4), where H4L is the centrosym. 1,5-diamino-9,10-anthraquinone, bpy is 2,2'-bipyridine, and pap is 2-phenylazopyridine. Electrochem. of the structurally characterized 1ClO4, 2ClO4, 3(ClO4)2, 4(ClO4)2, and 5(ClO4)2 reveals multistep oxidn. and redn. processes, which were analyzed by EPR of paramagnetic intermediates and by UV-visible-NIR spectro-electrochem. With support by time-dependent d. functional theory (DFT) calcns. the redox processes could be assigned. Significant results include the dimetal/bridging ligand mixed spin distribution in 33+ vs. largely bridge-centered spin in 43+-a result of the presence of RuII-stabilizing pap coligands. In addn. to the metal/ligand alternative for electron transfer and spin location, the dinuclear systems allow for the observation of ligand/ligand and metal/metal site differentiation within the multistep redox series. DFT-supported EPR and NIR absorption spectroscopy of the latter case revealed class II mixed-valence behavior of the oxidized asym. system 53+ with about equal contributions from a radical bridge formulation. In comparison to the analogs with the deprotonated 1,4-diaminoanthraquinone isomer the centrosym. H2L2- bridge shows anodically shifted redox potentials and weaker electronic coupling between the chelate sites. on SciFinder(R)
@article{Ansari.2016,
abstract = {The dinuclear complexes {(μ-H2L)[Ru(bpy)2]2}(ClO4)2 ([3](ClO4)2), {(μ-H2L)[Ru(pap)2]2}(ClO4)2 ([4](ClO4)2), and the asym. [(bpy)2Ru(\textgreek{m}-H2L)Ru(pap)2](ClO4)2 ([5](ClO4)2) were synthesized via the mononuclear species [Ru(H3L)(bpy)2]ClO4 ([1]ClO4) and [Ru(H3L)(pap)2]ClO4 ([2]ClO4), where H4L is the centrosym. 1,5-diamino-9,10-anthraquinone, bpy is 2,2'-bipyridine, and pap is 2-phenylazopyridine. Electrochem. of the structurally characterized [1]ClO4, [2]ClO4, [3](ClO4)2, [4](ClO4)2, and [5](ClO4)2 reveals multistep oxidn. and redn. processes, which were analyzed by EPR of paramagnetic intermediates and by UV-visible-NIR spectro-electrochem. With support by time-dependent d. functional theory (DFT) calcns. the redox processes could be assigned. Significant results include the dimetal/bridging ligand mixed spin distribution in 33+ vs. largely bridge-centered spin in 43+-a result of the presence of RuII-stabilizing pap coligands. In addn. to the metal/ligand alternative for electron transfer and spin location, the dinuclear systems allow for the observation of ligand/ligand and metal/metal site differentiation within the multistep redox series. DFT-supported EPR and NIR absorption spectroscopy of the latter case revealed class II mixed-valence behavior of the oxidized asym. system 53+ with about equal contributions from a radical bridge formulation. In comparison to the analogs with the deprotonated 1,4-diaminoanthraquinone isomer the centrosym. H2L2- bridge shows anodically shifted redox potentials and weaker electronic coupling between the chelate sites. [on SciFinder(R)]},
added-at = {2019-07-15T13:41:23.000+0200},
author = {Ansari, Mohd. Asif and Mandal, Abhishek and Paretzki, Alexa and Beyer, Katharina and Fiedler, Jan and Kaim, Wolfgang and Lahiri, Goutam Kumar.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/26709b2814a058475e9ee49fb48f506b0/b_schwederski},
doi = {10.1021/acs.inorgchem.6b00726},
interhash = {1a928eae2d766158e4047e82b4ea1ee9},
intrahash = {6709b2814a058475e9ee49fb48f506b0},
issn = {0020-1669},
journal = {Inorganic Chemistry},
keywords = {bipyridine complex complex;electrochem complex;ruthenium crystal diaminoanthracenedione dinuclear mononuclear phenyldiazenylpyridine prepn ruthenium spectroelectrochem structure},
number = 11,
pages = {5655--5670},
timestamp = {2019-07-15T11:42:10.000+0200},
title = {1,5-Diamido-9,10-anthraquinone, a Centrosymmetric Redox-Active Bridge with Two Coupled \textgreek{b}-Ketiminato Chelate Functions: Symmetric and Asymmetric Diruthenium Complexes},
volume = 55,
year = 2016
}