Electrochemistry represents one of the most intimate ways of interacting with molecules. This review discusses advances in synthetic organic electrochemistry since 2000. Enabling methods and synthetic applications are analyzed alongside innate advantages as well as future challenges of electroorganic chemistry.

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

Bioorganometallic Chemistry of Ferrocene

Organophosphorus π-Conjugated Materials

The conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT), and especially its complex with poly(styrene sulfonate) (PEDOT:PSS), is perhaps the most well-known example of an organic conductor. It is highly conductive, largely transmissive to light, processible in water, and highly flexible. Much recent work on this ubiquitous material has been devoted to increasing its deformability beyond flexibility-a characteristic possessed by any material that is sufficiently thin-toward stretchability, a characteristic that requires engineering of the structure at the molecular- or nanoscale. Stretchability is the enabling characteristic of a range of applications envisioned for PEDOT in energy and healthcare, such as wearable, implantable, and large-area electronic devices. High degrees of mechanical deformability allow intimate contact with biological tissues and solution-processable printing techniques (e.g., roll-to-roll printing). PEDOT:PSS, however, is only stretchable up to around 10%. Here, the strategies that have been reported to enhance the stretchability of conductive polymers and composites based on PEDOT and PEDOT:PSS are highlighted. These strategies include blending with plasticizers or polymers, deposition on elastomers, formation of fibers and gels, and the use of intrinsically stretchable scaffolds for the polymerization of PEDOT.

Stretchable Conductive Polymers and Composites Based on PEDOT and PEDOT:PSS.

Electrochemistry of redox-active self-assembled monolayers

Conducting polymers (CPs), thanks to their unique properties, structures made on-demand, new composite mixtures, and possibility of deposit on a surface by chemical, physical, or electrochemical methodologies, have shown in the last years a renaissance and have been widely used in important fields of chemistry and materials science. Due to the extent of the literature on CPs, this review, after a concise introduction about the interrelationship between electrochemistry and conducting polymers, is focused exclusively on the following applications: energy (energy storage devices and solar cells), use in environmental remediation (anion and cation trapping, electrocatalytic reduction/oxidation of pollutants on CP based electrodes, and adsorption of pollutants) and finally electroanalysis as chemical sensors in solution, gas phase, and chiral molecules. This review is expected to be comprehensive, authoritative, and useful to the chemical community interested in CPs and their applications.

Conducting Polymers in the Fields of Energy, Environmental Remediation, and Chemical–Chiral Sensors

Electron transfer (ET) through two configurations of double-stranded (ds)-DNA was investigated by the attachment of a ferrocenoyl (Fc)-labeled and thiol-labeled DNA to Au electrodes. The first configuration positions the Fc moiety on the same strand as the thiolate, whereas the second configuration positions the Fc group on the complementary strand. The subtle difference in structure leads to a difference in E0‘ values (29 mV) and in ET rate constants (25 vs 115 s-1). The results have led to a further understanding of electron transfer in ds-DNA, and several models of ET are proposed.

A Comparison of Electron-Transfer Rates of Ferrocenoyl-Linked DNA

The first imine-bridged pyridyltetrathiafulvalene building block (TTF−CHN−Py, 1) has been synthesized via the Schiff base condensation of formyltetrathiafulvalene and 2-aminopyridine. The preparation, X-ray crystal structure, electrochemical and magnetic characterization of a 1:1 copper complex [CuII(hfac)2(TTF−CHN−Py)] (2) are reported. The crystal structure reveals that the imine N atom participates in chelation to the paramagnetic center, thus making this ligand an attractive precursor for the assembly of π−d systems.

Preparation and coordination complex of the first imine-bridged tetrathiafulvalene-pyridine donor ligand.

The syntheses and characterization of two new tetrathiafulvalene (TTF) derivatives bearing pyridine-based substituents and 1,5‘-dimethyl-6-oxoverdazyl radicals are described. The TTF-pyridine and bipyridine aldehydes were prepared via a palladium-catalyzed cross-coupling reaction between mono(tributylstannyl)tetrathiafulvalene (3) and the appropriate formylpyridyl halides (4). The radical precursors, the corresponding 1,2,4,5-tetrazanes, were prepared by condensation of the bis(1-methylhydrazide) of carbonic acid with the TTF bearing pyridyl aldehyde. Oxidation of tetrazanes 8 and 9 with 1,4-benzoquinone afforded the donor radicals 1 and 2 as 1:1 complexes with hydroquinone. Both complexes are stable in the solid state and their electronic properties have been characterized by EPR, cyclic voltammetry, and UV/vis spectroscopy. The TTF core of both compounds was oxidized both chemically and electrochemically to afford the corresponding cation diradical species. The electronic properties of both donor radica...

Synthesis and characterization of a new family of spin bearing TTF ligands.

Aims: To identify the molecular networks in Pseudomonas ﬂuorescens thatconvey resistance to toxic concentrations of Zn, a common pollutant andhazard to biological systems.Methods and Results: Pseudomonas ﬂuorescens strain ATCC 13525 wascultured in growth medium with millimolar concentrations of Zn. Enzymaticactivities and metabolite levels were monitored with the aid of in-gel activityassays and high-performance liquid chromatography, respectively. As oxidativephosphorylation was rendered ineffective, the assimilation of citric acidmediated sequentially by citrate lyase (CL), phosphoenolpyruvate carboxylase(PEPC) and pyruvate phosphate dikinase (PPDK) appeared to play a key rolein ATP synthesis via substrate-level phosphorylation (SLP). Enzymes generatingthe antioxidant, reduced nicotinamide adenine dinucleotide phosphate(NADPH) were enhanced, while metabolic modules mediating the formationof the pro-oxidant, reduced nicotinamide adenine dinucleotide (NADH) weredownregulated.Conclusions: Pseudomonas ﬂuorescens reengineers its metabolic networks togenerate ATP via SLP, a stratagem that allows the microbe to compensate foran ineffective electron transport chain provoked by excess Zn.Signiﬁcance and Impact of the Study: The molecular insights described hereare critical in devising strategies to bioremediate Zn-polluted environments.IntroductionZn is an essential micronutrient in most if not all organ-isms as it is involved in a variety of biochemical pro-cesses. It plays a pivotal catalytic, structural andregulatory role (Stefanidou et al. 2006). This metal is animportant cofactor of numerous enzymes that are criticalin metabolism, transcription and cell signalling (Haaseand Rink 2009; Sera 2009; Bong et al. 2010). However,when present in elevated amounts, Zn interferes withnumerous biological pathways. This metal can interactstrongly with enzymatic imidazole and sulfhydryl groupsand arrest their reactions (Duruibe et al. 2007). Further-more, it disturbs the redox potential of the cell and helpsto create an oxidative environment. Indeed, oxidativestress is an important feature of Zn toxicity (Lemire et al.2008).Hence, to survive a Zn-polluted environment, a situa-tion common due to industrialization and anthropogenicactivity, organisms have evolved a plethora of intricatestrategies to combat this divalent metal (Bondarenkoet al. 2008). Its intracellular immobilization in phytochel-atins, metalothioneins and other cysteine-rich moietieshas been observed (Blindauer et al. 2002; Di Baccio et al.2005). Microbes living in Zn-polluted environments areknown to precipitate the metal as sulﬁde- or phosphate-containing moieties and actively efﬂux Zn (Radhika et al.2006). The synthesis of antioxidants, such as glutathioneand NADPH, is also part of the arsenal at the disposal ofbacteria to counter Zn (Lemire et al. 2010a; Poirier et al.2013). Although some of the molecular pathways thatmediate Zn detoxiﬁcation have been reported, theinvolvement of metabolic networks in the adaptation toelevated levels of Zn has yet to be fully uncovered.

https://sfamjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/jam.12497

M'hamed Chahma

Papers

Conducting Polymers in the Fields of Energy, Environmental Remediation, and Chemical–Chiral Sensors

A Comparison of Electron-Transfer Rates of Ferrocenoyl-Linked DNA

Preparation and coordination complex of the first imine-bridged tetrathiafulvalene-pyridine donor ligand.

Synthesis and characterization of a new family of spin bearing TTF ligands.

Zinc toxicity and ATP production in Pseudomonas fluorescens.