The Trityl Cation Embedded into a [7]Helicene-Like Backbone: Preparation and Application as a Lewis Acid Catalyst

The synthesis of a helically chiral carbenium ion is reported. The new motif is essentially a trityl cation embedded into a [7]helicene-like framework. The key step in its preparation establishes the π-extended fluorenone system in one step by an unprecedented palladium-catalyzed carbonylative annulation of a 4,4′-biphenanthryl-3,3′-diyl precursor. The racemic form of the new carbon Lewis acid was found to catalyze a representative set of reactions typically promoted by the trityl cation.

Ligand-enforced intimacy between a gold cation and a carbenium ion: Impact on stability and reactivity

Controlling the reactivity of transition metal complexes by positioning non-innocent functionalities around the catalytic pocket is a concept that has led to signifcant advances in catalysis. Here we describe our...

Helical Carbenium Ion-Based Organic Photoredox Catalyst: A Versatile and Sustainable Option in Red-Light-Induced Reactions

The development of a sustainable catalytic system for red-light-induced photocatalysis is presented. The catalytic system consists of a helical carbenium ion-based organic photoredox catalyst (PC) that is capable of using low-energy red light (λmax = 640 nm) for both photooxidations and photoreductions. Its successful applications in the aerobic oxidative hydroxylation of arylboronic acids and in the oxidation of benzylic C(sp3)–H bonds (reductive quenching), as well as in dual transition-metal/organocatalyzed C–H arylations and intermolecular atom-transfer radical additions (oxidative quenching) provide further support for its role as a versatile and efficient organic PC.1 Introduction2 Red-Light-Induced Photocatalysis3 Properties of N,N′-Dipropyl-1,13-dimethoxyquinacridinium Tetrafluoroborate4 Two Proposed Representative Catalytic Cycles of [ n Pr-DMQA+][BF4 –]5 Applications of [ n Pr-DMQA+][BF4 –] in Red-Light-Induced Photocatalysis6 Conclusion

Symmetric, Robust, and High-voltage Organic Redox Flow Battery Model Based on a Helical Carbenium Ion Electrolyte

Redox flow batteries (RFBs) represent a promising technology for grid-scale integration of renewable energy. Redox-active molecular pairs with large potential windows have been identified as key components of these systems. However, cross-contamination problems encountered by the use of different catholyte and anolyte species still limits the development of reliable organic RFBs. Herein, we report the first use of a helical carbenium ion, with three stable oxidation states, as electrolyte for the development of symmetric cells. Cyclic voltammo-amperometric studies were conducted in acetonitrile to assess the essential kinetic properties for flow battery performance and cycling stability of this molecule. The selected [4]helicenium ion was then evaluated by using mono- and bi-electronic cycling experiments, resulting in 745 and 80 cycles respectively, with near-perfect capacity retention. This helical carbenium ion based electrolyte achieved a proof-of-principle 2.12 V open circuit potential as an all-organic symmetric RFB.<br>

Symmetric, Robust, and High-voltage Organic Redox Flow Battery Model Based on a Helical Carbenium Ion Electrolyte

Redox flow batteries (RFBs) represent a promising technology for grid-scale integration of renewable energy. Redox-active molecular pairs with large potential windows have been identified as key components of these systems. However, cross-contamination problems encountered by the use of different catholyte and anolyte species still limits the development of reliable organic RFBs. Herein, we report the first use of a helical carbenium ion, with three stable oxidation states, as electrolyte for the development of symmetric cells. Cyclic voltammo-amperometric studies were conducted in acetonitrile to assess the essential kinetic properties for flow battery performance and cycling stability of this molecule. The selected [4]helicenium ion was then evaluated by using mono- and bi-electronic cycling experiments, resulting in 745 and 80 cycles respectively, with near-perfect capacity retention. This helical carbenium ion based electrolyte achieved a proof-of-principle 2.12 V open circuit potential as an all-organic symmetric RFB.<br>

Symmetric, Robust, and High-voltage Organic Redox Flow Battery Model Based on a Helical Carbenium Ion Electrolyte

Redox flow batteries (RFBs) represent a promising technology for grid-scale integration of renewable energy. Redox-active molecular pairs with large potential windows have been identified as key components of these systems. However, cross-contamination problems encountered by the use of different catholyte and anolyte species still limits the development of reliable organic RFBs. Herein, we report the first use of a helical carbenium ion, with three stable oxidation states, as electrolyte for the development of symmetric cells. Cyclic voltammo-amperometric studies were conducted in acetonitrile to assess the essential kinetic properties for flow battery performance and cycling stability of this molecule. The selected [4]helicenium ion was then evaluated by using mono- and bi-electronic cycling experiments, resulting in 745 and 80 cycles respectively, with near-perfect capacity retention. This helical carbenium ion based electrolyte achieved a proof-of-principle 2.12 V open circuit potential as an all-organic symmetric RFB.<br>