Controlling Near-Infrared Chromophore Electronic Properties through Metal–Ligand Orbital Alignment

2017 ◽  
Vol 139 (7) ◽  
pp. 2808-2815 ◽  
Author(s):  
Nicole M. Mews ◽  
Andreas Berkefeld ◽  
Gerald Hörner ◽  
Hartmut Schubert
1988 ◽  
Vol 43 (4) ◽  
pp. 371-381 ◽  
Author(s):  
K. Bütje ◽  
W. Preetz

AbstractWell-resolved IR and Raman spectra of the two sets of all 10 isomeric complexes [Os(NCS)n(SCN)6-n]3-/2-, n = 0-6, have been recorded. For both series, νCS(N) > νCS(S) and δNCS > δSCN; for the Os(III) complexes, vCN(N) ~ vCN(S) and vOsN ≥ vOsS while for the Os(IV) compounds, vCN(N) < vCN(S) and vOsN ~ vOsS. The vibrational spectra of the n = 0 and n = 6 members of both sets are assigned according to D3d and Oh point symmetry, respectively. For the mixed linkage isomers the band pattern is strongly influenced by pseudo-octahedral coupling wherever frequencies of N- and S-bonded groups coincide. The metal-ligand stretching region is therefore assigned according rather to pseudo-Oh, pseudo-D3d and pseudo-D4h symmetry than to D4h, C4v, C3v and C2v microsymmetry. The charge-transfer spectra of both series are similar, showing a parallel hypsochromic shift with increasing n value. Upon oxidation, a bathochromic shift of the CT bands by an average of 5400 cm-1 is observed, and the intensity increases by a factor 2-2.5. Weak absorptions in the near infrared region are assigned to intraconfigurational transitions.


2001 ◽  
Vol 664 ◽  
Author(s):  
M. Krause ◽  
H. Stiebig ◽  
R. Carius ◽  
H. Wagner

ABSTRACTFor sensor applications in the detection of near infrared light we have prepared μc-Ge:H by plasma enhanced chemical vapor deposition (PECVD) with a mixture of germane and hydrogen, investigatedits structural and electronic properties and incorporated it into thin pin diodes. In order to ensure microcrystalline growth we had to use high hydrogen dilution. However, only the material prepared with a ratio of germane to hydrogen of 0.2% shows high crystallinity. The optical absorption is remarkably different from c-Ge and exhibits no indication of a direct gap at 0.8eV. When this material is implemented as part of a 110nm thin absorber, a short circuit current of 20mA/cm2 and a quantum efficiency of 15% at a wavelength of 1.1μm are achieved. Higher germane concentrations in hydrogen lead to poor electronic properties due to an increase of the amorphous phase and the short circuit current of the devices deteriorates. As for crystalline germanium photodiodes cooling of the devices is used to overcome the restrictionoriginating from the high free carrier concentration.


2018 ◽  
Vol 6 (14) ◽  
pp. 3499-3513 ◽  
Author(s):  
Xiaodong Liu ◽  
Yiwei Lin ◽  
Yingjie Liao ◽  
Jiazun Wu ◽  
Yonghao Zheng

Both broadband and narrowband organic photodetectors can be realized due to the easily tunable optical/electronic properties of organic semiconductors.


2020 ◽  
Author(s):  
Morten Gotthold Vinum ◽  
Laura Voigt ◽  
Steen Hansen ◽  
Colby Bell ◽  
Kensha Marie Clark ◽  
...  

<p>The quest for simple ligands to participate in concerted base metal-ligand multiple-electron redox events is driven by perspectives of replacing noble metals in catalysis and for discovering novel chemical reactivity. Yet the vast majority of simple ligand systems displays electrochemical potentials impractical for catalytic cycles substantiating the importance of new strategies towards aligned metal–ligand orbital energy levels. We herein demonstrate the possibility to establish and tame the elusive <i>non-innocence</i> of the ubiquitous acetylacetonate (acac), that is the most commonly employed anionic, chelating ligand towards elements across the entire Periodic Table. By employing the ligand field in the high-spin Cr(II) as a thermodynamic switch, we were able to chemically tailor the occurrence of metal–ligand redox events. The very mechanism can be understood as a destabilization of the d<i><sub>z</sub></i>2 orbital relative to the <i>pi</i>* LUMO of acac, which proffers a generalizable strategy to synthetically engineer non-innocence with seemingly redox-inactive ligands. </p>


2011 ◽  
Vol 47 (27) ◽  
pp. 7647 ◽  
Author(s):  
David D. Schnaars ◽  
Enrique R. Batista ◽  
Andrew J. Gaunt ◽  
Trevor W. Hayton ◽  
Iain May ◽  
...  

2020 ◽  
Vol 56 (95) ◽  
pp. 15048-15051
Author(s):  
Chihiro Maeda ◽  
Takuma Shirakawa ◽  
Tadashi Ema

A highly conjugated carbazole-based fused diporphyrin shows NIR absorption.


2014 ◽  
Vol 16 (35) ◽  
pp. 18749-18758 ◽  
Author(s):  
Francesco Muniz-Miranda ◽  
Maria Cristina Menziani ◽  
Alfonso Pedone

A schematic description of the UV-vis spectrum of Au11(PPh3)7Cl3 nanoclusters. Metal → metal transitions are ubiquitous, metal → ligand transitions appear above the visible threshold, while ligand → metal and ligand → ligand transitions are much rarer in the investigated range of energies.


RSC Advances ◽  
2020 ◽  
Vol 10 (63) ◽  
pp. 38294-38303
Author(s):  
Kyle J. Colston ◽  
Sara A. Dille ◽  
Benjamin Mogesa ◽  
Jacilynn Brant ◽  
Victor N. Nemykin ◽  
...  

Two sets of FeIII/II complexes, synthesized from N,N′-diisopropyl piperazine-2,3-dithione (iPr2Dt0) and N,N′-dimethyl piperazine-2,3-dithione (Me2Dt0) ligands, exhibit electronically asymmetrical ligands with metal–ligand orbital mixing.


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