Unprecedented metal–metal bonded {Ru4(μ3-O)2} butterfly core in oxido-carboxylato bridged mixed valence cluster—structural elucidation and electronic forms in accessible redox states

2020 ◽  
Vol 49 (39) ◽  
pp. 13573-13581
Author(s):  
Sudip Kumar Bera ◽  
Goutam Kumar Lahiri

A metal–metal bonded butterfly core in mixed valence 1 (RuIII3RuIV, S = 1/2) displayed near-infrared absorption and anisotropic EPR, while oxidised 1+ (RuIII2RuIV2) or reduced 1− (RuIII4) is attributed to the spin-paired S = 0 state.

2001 ◽  
Vol 79 (2) ◽  
pp. 145-156
Author(s):  
Reginaldo C Rocha ◽  
Henrique E Toma

The unsymmetrical dinuclear ruthenium–iron complexes [(NH3)5Ru–bta–Fe(CN)5]n (where bta = benzotriazolate; n = –2, –1, 0) were prepared as solid sodium salts from [RuII(NH3)5(bta)]+ or [RuIII(NH3)5(bta)]2+ and [FeII(CN)5(H2O)]3– and characterized in aqueous solution by means of electrochemical and spectroelectrochemical methods. UV-vis, near-infrared, IR, and cyclic and differential pulse voltammetry data suggest that the related mixed valent species belong to a valence trapped formulation, featuring localized Ru(III) and Fe(II) oxidation states. In spite of the class II categorization in the Robin and Day scheme, this system shows a remarkable metal–metal electronic coupling, as deduced from an intense, low-energy, and very broad intervalence band in the near-IR region. In addition, the mixed valence state displays enhanced stabilization in relation to the isovalent state. The intervalence transfer properties are discussed on the basis of Hush's theory.Key words: ammineruthenium complexes, cyanoiron complexes, mixed valence, intervalence, benzotriazole, benzotriazolate.


2010 ◽  
Vol 25 (10) ◽  
pp. 1029-1033
Author(s):  
Shi-Xing XIA ◽  
Chun-Hui YANG ◽  
Chong-Qiang ZHU ◽  
Tian-Hui MA ◽  
Meng WANG ◽  
...  

2021 ◽  
Author(s):  
Shinya Sugiura ◽  
Hiromitsu Maeda

A new series of π-extended quinone derivatives containing a pyrrole bridge exhibited NH/OH-type tautomerization and anion binding along with deprotonation that induced near-infrared absorption and ion-pairing assemblies.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ibrahim Shaik ◽  
S. K. Begum ◽  
P. V. Nagamani ◽  
Narayan Kayet

AbstractThe study demonstrates a methodology for mapping various hematite ore classes based on their reflectance and absorption spectra, using Hyperion satellite imagery. Substantial validation is carried out, using the spectral feature fitting technique, with the field spectra measured over the Bailadila hill range in Chhattisgarh State in India. The results of the study showed a good correlation between the concentration of iron oxide with the depth of the near-infrared absorption feature (R2 = 0.843) and the width of the near-infrared absorption feature (R2 = 0.812) through different empirical models, with a root-mean-square error (RMSE) between < 0.317 and < 0.409. The overall accuracy of the study is 88.2% with a Kappa coefficient value of 0.81. Geochemical analysis and X-ray fluorescence (XRF) of field ore samples are performed to ensure different classes of hematite ore minerals. Results showed a high content of Fe > 60 wt% in most of the hematite ore samples, except banded hematite quartzite (BHQ) (< 47 wt%).


2018 ◽  
Vol 24 (72) ◽  
pp. 19341-19347 ◽  
Author(s):  
Houjia Wei ◽  
Rui Feng ◽  
Yong Fang ◽  
Lei Wang ◽  
Chao Chen ◽  
...  

2018 ◽  
Vol 2 (12) ◽  
pp. 2333-2339 ◽  
Author(s):  
Junhui Miao ◽  
Junxia Wang ◽  
Bin Meng ◽  
Jun Liu ◽  
Lixiang Wang

We report a new A–D–A′–D–A type small molecule acceptor with a wide absorption spectrum spanning from 300 nm to 900 nm and a bandgap of only 1.39 eV.


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