scholarly journals Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

2015 ◽  
Vol 11 ◽  
pp. 1596-1613 ◽  
Author(s):  
Masahiko Iyoda ◽  
Masashi Hasegawa
Keyword(s):  
Mixed Valence ◽  
Supramolecular Assembly ◽  
Radical Cations ◽  
Supramolecular Assemblies ◽  
Supramolecular Structures ◽  
Oxidation States ◽  
Face To Face ◽  
Redox Active ◽  
Nanophase Separation ◽  
Self Organizing

The construction of redox-active supramolecular assemblies based on star-shaped and radially expanded tetrathiafulvalene (TTF) oligomers with divergent and extended conjugation is summarized. Star-shaped TTF oligomers easily self-aggregate with a nanophase separation to produce supramolecular structures, and their TTF units stack face-to-face to form columnar structures using the fastener effect. Based on redox-active self-organizing supramolecular structures, conducting nanoobjects are constructed by doping of TTF oligomers with oxidants after the formation of such nanostructures. Although radical cations derived from TTF oligomers strongly interact in solution to produce a mixed-valence dimer and π-dimer, it seems to be difficult to produce nanoobjects of radical cations different from those of neutral TTF oligomers. In some cases, however, radical cations form nanostructured fibers and rods by controlling the supramolecular assembly, oxidation states, and counter anions employed.

scholarly journals Electrochemical and Spectroelectrochemical Studies on the Reactivity of Perimidine–Carbazole–Thiophene Monomers towards the Formation of Multidimensional Macromolecules versus Stable π-Dimeric States

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2167
Author(s):  
Malgorzata Czichy ◽  
Patryk Janasik ◽  
Pawel Wagner ◽  
David L. Officer ◽  
Mieczyslaw Lapkowski
Keyword(s):  
Conjugated Polymer ◽  
Density Functional ◽  
Radical Cations ◽  
Covalent Bonding ◽  
Oxidation States ◽  
Solid Product ◽  
Functional Theory ◽  
Subsequent Oxidation ◽  
Molecular Ordering ◽  
Significant Difference

During research on cross-linked conducting polymers, double-functionalized monomers were synthesized. Two subunits potentially able to undergo oxidative coupling were used—perimidine and, respectively, carbazole, 3,6-di(hexylthiophene)carbazole or 3,6-di(decyloxythiophene)carbazole; alkyl and alkoxy chains as groups supporting molecular ordering and 14H-benzo[4,5]isoquinone[2,1-a]perimidin-14-one segment promoting CH⋯O interactions and π–π stacking. Electrochemical, spectroelectrochemical, and density functional theory (DFT) studies have shown that potential-controlled oxidation enables polarization of a specific monomer subunit, thus allowing for simultaneous coupling via perimidine and/or carbazole, but mainly leading to dimer formation. The reason for this was the considerable stability of the dicationic and tetracationic π-dimers over covalent bonding. In the case of perimidine-3,6-di(hexylthiophene)carbazole, the polymer was not obtained due to the steric hindrance of the alkyl substituents preventing the coupling of the monomer radical cations. The only linear π-conjugated polymer was obtained through di(decyloxythiophene)carbazole segment from perimidine-di(decyloxythiophene)-carbazole precursor. Due to the significant difference in potentials between subsequent oxidation states of monomer, it was impossible to polarize the entire molecule, so that both directions of coupling could be equally favored. Subsequent oxidation of this polymer to polarize the side perimidine groups did not allow further crosslinking, because rather the π–π interactions between these perimidine segments dominate in the solid product.

ChemInform Abstract: [V16O38(CN)]9-: A Soluble Mixed-Valence Redox-Active Building Block with Strong Antiferromagnetic Coupling.

ChemInform ◽  
2012 ◽  
Vol 43 (45) ◽  
pp. no-no
Author(s):  
Tony D. Keene ◽  
Deanna M. D'Alessandro ◽  
Karl W. Kraemer ◽  
Jason R. Price ◽  
David J. Price ◽  
...  
Keyword(s):  
Building Block ◽  
Mixed Valence ◽  
Antiferromagnetic Coupling ◽  
Redox Active

Half-sandwich manganese complexes Cp(CO)2Mn(NHC) as redox-active organometallic fragments

2021 ◽  
Author(s):  
Rémy Brousses ◽  
Vincent Maurel ◽  
Jean-Marie Mouesca ◽  
Vincent Cesar ◽  
Noël Lugan ◽  
...  
Keyword(s):  
Radical Cations ◽  
Manganese Complexes ◽  
Carbene Ligands ◽  
Redox Active ◽  
Half Sandwich

Oxidation of the half-sandwich MnI complexes Cp(CO)2Mn(NHC) bearing dialkyl-, arylalkyl- and diarylsubstituted N-heterocyclic carbene ligands (NHC = IMe, IMeMes, IMes) affords the corresponding stable MnII radical cations [Cp(CO)2Mn(NHC)](BF4) isolated in...

scholarly journals Pyramidal Heteroanion-Directed and Reduced MoV-Driven Assembly of Multi-Layered Polyoxometalate Cages

2018 ◽  
Author(s):  
Qi Zheng, ◽  
Manuel Kupper ◽  
Weimin Xuan ◽  
Hirofumi Oki ◽  
Ryo Tsunashima ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Mixed Valence ◽  
The Self ◽  
Model Structure ◽  
Redox Titration ◽  
Metal Centers ◽  
Redox Active ◽  
Tetrabutyl Ammonium

The fabrication of redox-active polyoxometalates (POMs) that can switch between multiple states is critical for their application in electronic devices, yet, a sophisticated synthetic methodology is not well developed for such cluster types. Here we describe the heteroanion-directed and reduction-driven assembly of a series of multi-layered POM cages 1-10 templated by 1-3 redox-active pyramidal heteroanions. The heteroanions greatly affect the selfassembly of the resultant POM cages, leading to the generation of unprecedented three-layered peanut-shaped - 4, 7 and 8 - or bulletshaped - 5 and 6 - structures. The introduction of reduced molybdate is essential for the self-assembly of the compounds and results in mixed-metal (W/Mo), and mixed-valence (WVI/MoV) 1-10, as confirmed by redox titration, UV-Vis-NIR, NMR spectroscopy and mass spectrometry. 11, the tetrabutyl ammonium (TBA) salt derivative of the fully oxidized 3, is produced as a model structure for measurements to confirm that 1-10 are a statistical mixture of isostructural clusters with different ratios of W/Mo. Finally, multilayered POM cages exhibit dipole relaxations due to the presence of mixed valence WVI/MoV metal centers, demonstrating their potential uses for electronic materials.

scholarly journals Highly-organized stacked multilayers via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes. Stratified supramolecular structures for (bio)electrochemical nanoarchitectonics

Soft Matter ◽  
2018 ◽  
Vol 14 (10) ◽  
pp. 1939-1952 ◽  
Author(s):  
M. Lorena Cortez ◽  
Agustín Lorenzo ◽  
Waldemar A. Marmisollé ◽  
Catalina von Bilderling ◽  
Eliana Maza ◽  
...  
Keyword(s):  
Supramolecular Structures ◽  
Layer By Layer ◽  
Layer By Layer Assembly ◽  
Redox Active ◽  
Self Assembled ◽  
Layer Assembly

Redox-active and (bio)functional hosts can be deliberately located in self-assembled stratified domains.

Ligand mixed-valence and electrical conductivity in coordination complexes containing a redox-active phenalenol-substituted ligand

2019 ◽  
Vol 48 (23) ◽  
pp. 8053-8056 ◽  
Author(s):  
Sarah Dale ◽  
Nico M. Bonanno ◽  
Mark Pelaccia ◽  
Alan J. Lough ◽  
Atsuhiro Miyawaki ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Mixed Valence ◽  
Closed Shell ◽  
Coordination Complexes ◽  
Low Energy ◽  
Redox Active

Neutral Fe3+ and Co3+ complexes are reported featuring mixed-valent open- and closed-shell ligands, low energy IVCT bands and electrical conductivity.

The crystal structures of the mixed-valence tellurium oxysalts tlapallite, (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, and carlfriesite, CaTe4+2Te6+O8

2019 ◽  
Vol 83 (4) ◽  
pp. 539-549 ◽  
Author(s):  
Owen P. Missen ◽  
Anthony R. Kampf ◽  
Stuart J. Mills ◽  
Robert M. Housley ◽  
John Spratt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mixed Valence ◽  
Oxidation States ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
The One ◽  
Micro Analysis ◽  
Secondary Bonding

ABSTRACTThe crystal structure of tlapallite has been determined using single-crystal X-ray diffraction and supported by electron probe micro-analysis, powder diffraction and Raman spectroscopy. Tlapallite is trigonal, space groupP321, witha= 9.1219(17) Å,c= 11.9320(9) Å andV= 859.8(3) Å3, and was refined toR1= 0.0296 for 786 reflections withI> 2σ(I). This study resulted from the discovery of well-crystallised tlapallite at the Wildcat prospect, Utah, USA. The chemical formula of tlapallite has been revised to (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, or more simply (Ca,Pb)3CaCu6Te4+8Te6+2O30(SO4)2·3H2O, from H6(Ca,Pb)2(Cu,Zn)3(TeO3)4(TeO6)(SO4). The tlapallite structure consists of layers containing distorted Cu2+O6octahedra, Te6+O6octahedra and Te4+O4disphenoids (which together form the new mixed-valence phyllotellurate anion [Te4+3Te6+O12]12−), Te4+O3trigonal pyramids and CaO8polyhedra. SO4tetrahedra, Ca(H2O)3O6polyhedra and H2O groups fill the space between the layers. Tlapallite is only the second naturally occurring compound containing tellurium in both the 4+and 6+oxidation states with a known crystal structure, the other being carlfriesite, CaTe4+2Te6+O8. Carlfriesite is the predominant secondary tellurium mineral at the Wildcat prospect. We also present an updated structure for carlfriesite, which has been refined toR1= 0.0230 for 874 reflections withI> 2σ(I). This updated structural refinement improves upon the one reported previously by refining all atoms anisotropically and presenting models of bond valence and Te4+secondary bonding.

scholarly journals Face-to-Face Dimeric Tetrathiafulvalenes and Their Cation Radical and Dication Species as Models of Mixed Valence and π-Dimer States

2012 ◽  
Vol 85 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Masashi Hasegawa ◽  
Kota Daigoku ◽  
Kenro Hashimoto ◽  
Hiroyuki Nishikawa ◽  
Masahiko Iyoda
Keyword(s):  
Mixed Valence ◽  
Cation Radical ◽  
Face To Face

Electronic Properties of some Ternary and Quaternary Oxides of the VIII B and I B Transition Elements: Application to High Tc Superconductivity

1989 ◽  
Vol 156 ◽  
Author(s):  
M. Pouchard ◽  
J-C. Grenier ◽  
J-P. Doumerc ◽  
G. Demazeau ◽  
J-P. Chaminade ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Structural Parameters ◽  
Mixed Valence ◽  
Oxidation States ◽  
Transition Elements ◽  
High Tc Superconductors ◽  
High Tc ◽  
Electronic Configurations ◽  
Spin Electronic ◽  
Mixed Valence Compounds

ABSTRACTIn the scope of the Goodenough model, a brief review of the electronic properties of some 3d transition elements (M = Fe, Co, Ni and Cu ) is given; the main relevant electronic and structural parameters are emphasized. Then a special attention is focussed on N/(N−1) and N/(N−2) electron mixed valence compounds.Finally some particular features of copper are discussed and their relevance to high Tc superconductors is pointed out:-the srong covalency of Cu-O bondings involving a possible delocalization of the hole between trivalent copper and oxygen,-the existence of low and high spin electronic configurations for CuIII,-the disproportionation of Cu2+ and its role in the formation of hole pairs,Cu-O distances very close for the three successive oxidation states of copper favouring the disproportionation process.

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