scholarly journals Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

2021 ◽  
Vol 17 ◽  
pp. 273-282 ◽  
Author(s):  
Sergey V Norkov ◽  
Anton V Cherkasov ◽  
Andrey S Shavyrin ◽  
Maxim V Arsenyev ◽  
Viacheslav A Kuropatov ◽  
...  
Keyword(s):  
Metal Ions ◽  
Spin Density ◽  
Functional Groups ◽  
Quinone Methide ◽  
Redox Activity ◽  
The Novel ◽  
Redox Active Ligands ◽  
Redox Active ◽  
Sterically Hindered ◽  
Quinone Derivative

The fused 1,3-dithiole spacer seems to be very suitable for the functionalization of sterically hindered o-quinones with additional groups capable of coordination of metal ions and/or possessing a redox activity. An effective method for the synthesis of sterically hindered o-quinones containing 1,3-diketonate, dinitrile and p-quinone-methide functional groups at the periphery of the ligand has been developed. The novel compounds have rigid and conjugated structures and exhibit properties typical of o-quinones. A study of their monoreduced semiquinone derivatives reveal that the spin density is delocalized across the whole molecule, including peripheral fragments. The first stable o-quinone derivative bearing an annulated thiete heterocycle has been isolated and characterized.

Host molecules containing electroactive cavities obtained by the molecular assembly of redox-active ligands and metal ions

1995 ◽  
pp. 1643-1644 ◽  
Author(s):  
María José L. Tendero ◽  
Angel Benito ◽  
Juan Cano ◽  
Jose Manuel Lloris ◽  
Ramón Martínez-Máñez ◽  
...  
Keyword(s):  
Metal Ions ◽  
Molecular Assembly ◽  
Redox Active Ligands ◽  
Host Molecules ◽  
Redox Active

scholarly journals Rich Redox-Activity and Solvatochromism in a Family of Heteroleptic Cobalt Complexes

2021 ◽  
Author(s):  
Vincent L. Nadurata ◽  
Moya Hay ◽  
Jett Tao Janetzki ◽  
Gemma Kate Gransbury ◽  
Colette Boskovic
Keyword(s):  
Charge Transfer ◽  
Cobalt Complexes ◽  
Redox Activity ◽  
Redox Active Ligands ◽  
Valence Tautomerism ◽  
Redox Active ◽  
Active Metal ◽  
Metal Redox ◽  
Redox Active Metal

The combination of redox-active metals with redox-active ligands can lead to interesting charge transfer behaviours, including valence tautomerism and solvatochromism. With the aim of investigating a relatively underexplored redox-active metal/redox-active...

scholarly journals Small Molecule-Induced Intramolecular Electron “Pitch and Catch” in a RhodiumIComplex with Substitutionally Inert Redox-Active Ligands.

1999 ◽  
Vol 38 (18) ◽  
pp. 4176-4176
Author(s):  
Igor V. Kourkine ◽  
Caroline S. Slone ◽  
Chad A. Mirkin ◽  
Louise M. Liable-Sands ◽  
Arnold L. Rheingold
Keyword(s):  
Small Molecule ◽  
Redox Active Ligands ◽  
Redox Active

scholarly journals Anodic Stripping Voltammetry with the Hanging Mercury Drop Electrode for Trace Metal Detection in Soil Samples

Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 107
Author(s):  
Kequan Xu ◽  
Clara Pérez-Ràfols ◽  
Amine Marchoud ◽  
María Cuartero ◽  
Gastón A. Crespo
Keyword(s):  
Metal Ions ◽  
Limit Of Detection ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Hanging Mercury Drop Electrode ◽  
Mercury Drop Electrode ◽  
Redox Active ◽  
Active Metal ◽  
Metal Detection ◽  
Trace Metal Detection

The widely spread use of the hanging mercury drop electrode (HMDE) for multi-ion analysis is primarily ascribed to the following reasons: (i) excellent reproducibility owing to the easy renewal of the electrode surface avoiding any hysteresis effect (i.e., a new identical drop is generated for each measurement to be accomplished); (ii) a wide cathodic potential window originating from the passive hydrogen evolution and solvent electrolysis; (iii) the ability to form amalgams with many redox-active metal ions; and (iv) the achievement of (sub)nanomolar limits of detection. On the other hand, the main controversy of the HMDE usage is the high toxicity level of mercury, which has motivated the scientific community to question whether the HMDE deserves to continue being used despite its unique capability for multi-metal detection. In this work, the simultaneous determination of Zn2+, Cd2+, Pb2+, and Cu2+ using the HMDE is investigated as a model system to evaluate the main features of the technique. The analytical benefits of the HMDE in terms of linear range of response, reproducibility, limit of detection, proximity to ideal redox behavior of metal ions and analysis time are herein demonstrated and compared to other electrodes proposed in the literature as less-toxic alternatives to the HMDE. The results have revealed that the HMDE is largely superior to other reported methods in several aspects and, moreover, it displays excellent accuracy when simultaneously analyzing Zn2+, Cd2+, Pb2+, and Cu2+ in such a complex matrix as digested soils. Yet, more efforts are required towards the definitive replacement of the HMDE in the electroanalysis field, despite the elegant approaches already reported in the literature.

Utilizing o-quinone methide chemistry: synthesis of sterically hindered acridin-4-ols

2021 ◽  
Vol 31 (2) ◽  
pp. 262-264
Author(s):  
Svetlana K. Polyakova ◽  
Tatyana V. Balashova ◽  
Roman V. Rumyantcev ◽  
Maxim V. Arsenyev ◽  
Georgy K. Fukin ◽  
...  
Keyword(s):  
Quinone Methide ◽  
Sterically Hindered

scholarly journals Rosuvastatin cocrystals: an attempt to modulate physicochemical parameters

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Venkata Deepthi Vemuri ◽  
Srinivas Lankalapalli
Keyword(s):  
Physicochemical Properties ◽  
Dissolution Rate ◽  
Functional Groups ◽  
Preliminary Investigation ◽  
Scale Up ◽  
Solvent Evaporation ◽  
Molar Ratio ◽  
The Novel ◽  
Formulation Development ◽  
Hydrogen Bond Interaction

Abstract Background The meager physicochemical properties like low solubility and low dissolution rate of rosuvastatin calcium remain as an obstruction for formulation development. In the present work, we explore the evolution of rosuvastatin cocrystal, which may offer the synergetic physico-chemical properties of the drug. Cocrystal crafting depends on two possible intermolecular interactions; heteromeric and the homomeric selection of compounds with complementary functional groups are contemplated as a possible cause of supramolecular synthons in cocrystal formation. Specifically, cocrystals of rosuvastatin with l-asparagine and l-glutamine with molar ratio (1:1) were fabricated by using slow solvent evaporation and slow evaporation techniques. Novel cocrystals of rosuvastatin-asparagine (RSC-C) and rosuvastatin-glutamine (RSC-G) cocrystals obtained by slow solvent evaporation were utilized for preliminary investigation and further scale-up was done by using the solvent evaporation technique. Results The novel cocrystals showed a new characteristic of powder X-ray diffraction, thermograms of differential scanning calorimetry, 1H liquid FT-NMR spectra, and scanning electron microscopy. These results signify the establishment of intermolecular interaction within the cocrystals. In both the novel cocrystals, rosuvastatin was determined to be engaged in the hydrogen bond interaction with the complementary functional groups of l-asparagine and l-glutamine. Compared with the pure rosuvastatin, RSC-C and RSC-G cocrystal showed 2.17-fold and 1.60-fold improved solubility respectively. The dissolution test showed that the RSC-C and RSC-G cocrystal exhibited 1.97-fold and 1.94-fold higher dissolution rate than the pure rosuvastatin in pH6.8 phosphate buffer respectively. Conclusion Modulation in the chemical environment, improvement in the solubility, and dissolution rate demonstrated the benefit of co-crystallization to improve the physicochemical properties of the drug. Graphical abstract

Metal-Metal Interactions in Heterobimetallic Complexes with Dinucleating Redox-Active Ligands

2016 ◽  
Vol 128 (7) ◽  
pp. 2452-2456 ◽  
Author(s):  
Daniël L. J. Broere ◽  
Dieuwertje K. Modder ◽  
Eva Blokker ◽  
Maxime A. Siegler ◽  
Jarl Ivar van der Vlugt
Keyword(s):  
Redox Active Ligands ◽  
Metal Interactions ◽  
Heterobimetallic Complexes ◽  
Redox Active ◽  
Metal Metal
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