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A single layer of a dyad made of a cobalt(II) bis‐terpyridine complex functionalized with a Boron‐dipyrromethene (BODIPY) fluorophore on transparent Indium Tin Oxide (ITO) electrode is prepared. A modulation of the photoluminescence intensity of the fluorophore upon the application of an electric stimulus on the ITO electrode that supports 10 picomoles of molecules is demonstrated. The intensity of the fluorescence intensity decreases when the cobalt is at the oxidation state +III, due to CoIII oxidative quenching of BODIPY emission that has a higher driving force than the CoII reductive quenching initially responsible for the low fluorescence intensity of the chemisorbed dyad. [ABSTRACT FROM AUTHOR]

New tetrazine derivatives were prepared and their electrochemical properties as well as their reactivity in the inverse demand Diels−Alder (DAinv) reaction were investigated. DFT calculations were performed to calculate the energy and electronic distribution in the frontier molecular orbitals. In particular, the reactivity of these tetrazine derivatives has been compared with that of the already known dichlorotetrazine. A comparison of the gathered data allows a rough correlation to be established between the reactivity and the electron-withdrawing character of the substituent, but only a closer examination of the involved orbitals can enable an accurate prediction of the DAinv reactivity of the investigated compounds. [ABSTRACT FROM AUTHOR]

Abstract: The first example of thin layer electrochemistry coupled to epifluorescence microscopy in the total internal reflectance mode is described and applied to the investigation of electrochemically modulated fluorescence of an organic dye (chloromethoxytetrazine) in solution. This technique allows to generate full redox switch of fluorescence when converting reversibly the dye into its anion radical, as well as to record the spectral features of the electrogenerated species. Recording simultaneously fluorescence intensity and lifetime along with coulombic charge as a function of the electrode potential will lead to a deep insight into the redox quenching mechanism. [Copyright &y& Elsevier]

• In this review, we highlight the very special nature of tetrazines' fluorescence, and the new repercusssions of this in various fields. We especially detailed the incidence in the field of electrofluorochromism, which started precisely with our work on tetrazines' fluorescence extinction by electrochemical reduction. • We also devote a large special section on new tetrazines' applications, from revelation of fingerprints to imaging of friction concact surfaces, passing through photons down-conversion and new polymer coatings. • The detailed description of the use of tetrazines in the field of fluorescence and chemically induced fluorescence switching is provided. The 1,2,4,5-Tetrazines, or s-tetrazines, are a particular example of small, high nitrogen content heterocycle with extremely original physico-chemical properties. In this review, we summarize the last 20 years of research on this topic, focusing more on fluorescence and related optical properties on tetrazines, and tetrazine derived materials. [ABSTRACT FROM AUTHOR]

Bis[5-(2,2′-bithienyl)]tetrazine has been synthesized and polymerized electrochemically. This is the first example of an electroactive polymer containing a tetrazine moiety in the main chain. In addition, reduction of the tetrazine ring has been shown to be possible in the films. [Copyright &y& Elsevier]

Abstract: Original new electroactive dyads have been prepared, featuring two different electroactive groups, namely a triphenylamine and a tetrazine, linked through various linkers. We describe here the synthesis, the electrochemical and some photophysical properties of these molecules which are composed of two separate components, one triphenylamine, electron-rich unit, and one tetrazine, electron-poor unit. The electroactivity of both moieties of the molecule is quite apparent in each case and potentials depend upon the type of linker between the groups. [Copyright &y& Elsevier]

Abstract: We describe the synthesis of two new polymerizable monomers, based on respectively one thiophene–pyrrole–thiophene (SNS) moiety and one carbazole moiety, both functionalized by 3-chloro-6-alkoxy-s-tetrazine pendant groups. The electrochemical response of the monomers and the subsequent polymers has been studied both by cyclic voltametry and UV–visible spectroscopy. In both case conducting polymers are obtained, featuring both the redox activity of the main chain in oxidation and of the tetrazine functional group upon reduction, but only the one stemming from the SNS moiety is stable to cycling. The spectroscopic and electrochemical characteristics of both the monomer and the polymer are detailed herein, and especially a stable film has been obtained on an ITO plate. [Copyright &y& Elsevier]

Abstract: Several new s-tetrazines have been prepared with hindered, electron-withdrawing or electron-rich substituents. This is the first time that tetrazine bearing interactive functional groups other than ligands are described… Their electrochemical and spectroscopic properties have been investigated, especially concerning the electron transfer rate in the case of three selected compounds. Fluorescence occurs as expected as soon as the substituent linked to the tetrazine core is electron withdrawing enough. The existence of the tetrazine fluorescence with imide substituents might open the way to the preparation of bichomophoric fluorophores. [Copyright &y& Elsevier]

Abstract: New systems consisting in ferrocenes conjugated with a pyridinium core have been synthesized, and their electrochemistry has been studied in a conventional electrolyte. All ferrocenes exhibit a reversible wave as expected, however the pyridinium reduction was somewhat surprisingly found only weakly reversible, enough however to allow comparison of the number of electrons transferred between the anodic and cathodic process. All compounds give single oxidation waves with 2 or 3 electrons exchanged depending on the number of ferrocenes. An attempt to draw diffusion coefficients from the analysis of the variation of peak currents vs. scan rate has been made, showing that 2-branch compounds diffuse slightly faster than 3-branch ones. However, the differences between the two series is less than one could predict from calculation with sphere-like and rod-like molecules. [Copyright &y& Elsevier]

Abstract: New tetrazines substituted by heteroatomic substituents have been prepared, and their physicochemical properties investigated. In particular, a cyclophane containing three tetrazine units was synthesised and its crystal structure demonstrated. The electrochemical and fluorescence properties of these new compounds were investigated, as well as the sensing ability of the cyclophane toward several electron-rich and hydroxy substituted compounds. Interactions between the anion-radical of the tetrazine compounds and the phenol derivative were evidenced through spectroscopic and electrochemical measurements. In the case of the cyclophane compounds, these interactions occur probably through H-bonding, whereas proton transfer is evidenced in the case of the linear bisbutanedioxy substituted tetrazine. [Copyright &y& Elsevier]

The synthesis, reactivity and properties of a series of four polypyridyl ruthenium complexes have been studied. These complexes were used to post-functionalize preformed 3 nm silver and gold nanoparticles (NPs) in water and in dichloromethane (DCM). We studied the influence of the grafted complexes on the formation process and stability of the colloidal solutions and we investigated the optical and electrochemical properties of the final nanocomposites. Among the series of four ruthenium complexes, three novel heteroleptic complexes (1 – 3) bearing one pyridine, one amine or two carboxydithioic acid pendant groups were synthesized and reacted with preformed Au-NPs and Ag-NPs. Results were compared to those obtained with the model [Ru(bpy) 3 2+ complex (4). The strength of the interaction between the anchoring group and the surface of NPs influenced the size, shape and stability of the final nanocomposites. Polar solvent such as water induced aggregation and lead to unstable nanocomposites. Stationary and time resolved luminescence of grafted nanocomposites (1–3) showed that the luminescence of complexes were completely quenched (lifetime and emission quantum yield) in water by electron transfer processes, moreover electrical measurements rationalize that Ag nanocomposites exhibit the stronger quenching due to a lower oxidation potential. It also showed a current enhancement associated with double layer charging of the metal nanoparticle cores. Unlabelled Image • The synthesis of four polypyridyl ruthenium complexes was done. • The reactivity and properties of complexes have been studied. • Postfunctionalization of silver and gold nanoparticles was carried out. • Mutual influence between nanoparticles and the grafted complexes was investigated. [ABSTRACT FROM AUTHOR]