Water-Stable, Eight-electron Acceptor Drives Anion⋅⋅⋅Water Assisted Tunable Ionic Self-Assembly and Proton Conduction.

Organic π-scaffolds are being envisaged for new-age electron- and ion-responsive materials that can accumulate electrons as well as transport proton. However, such systems are extremely rare as electron-deficient scaffolds are unstable in aqueous solution. Here we detail the synthesis of a water-stable core-naphthalenediimide-nitrobenzyl-viologen based tetra-cation, which accumulates up to eight-electrons within an exceptionally narrow potential window of +0.

The windmill, the dragon, and the frog: geometry control over the spectral, magnetic, and electrochemical properties of cobalt phthalocyanine regioisomers.

For the first time, we have prepared non-aggregating phthalocyanine cobalt complexes as a set of resolved positional isomers. These compounds comprise a unique test bed for the structure-properties studies, as their optical and electrochemical properties are influenced by the planarity of the phthalocyanine macrocycle, which can be controlled by the positional isomerism of the bulky aromatic substituents at the -phthalo sites. We support our conclusions with molecular modelling studies, which show a perfect match between the calculated and experimentally determined spectral/electrochemical values.

Electrochemically controlled rectification in symmetric single-molecule junctions.

Single-molecule electrochemical science has advanced over the past decades and now extends well beyond molecular imaging, to molecular electronics functions such as rectification and amplification. Rectification is conceptually the simplest but has involved mostly challenging chemical synthesis of asymmetric molecular structures or asymmetric materials and geometry of the two enclosing electrodes. Here we propose an experimental and theoretical strategy for building and tuning in situ (in operando) rectification in two symmetric molecular structures in electrochemical environment.

Intussusception in children aged under two years in India: Retrospective surveillance at nineteen tertiary care hospitals.

Objective: Intussusception has been linked with rotavirus vaccine (RVV) as a rare adverse reaction. In view of limited background data on intussusception in India and in preparation for RVV introduction, a surveillance network was established to document the epidemiology of intussusception cases in Indian children.

Methods: Intussusception in children 2-23 months were documented at 19 nationally representative sentinel hospitals through a retrospective surveillance for 69 months (July 2010 to March 2016).

Highly Oxidized States of Phthalocyaninato Terbium(III) Multiple-Decker Complexes Showing Structural Deformations, Biradical Properties and Decreases in Magnetic Anisotropy.

Presented here is a comprehensive study of highly oxidized multiple-decker complexes composed of Tb and Cd ions and two to five phthalocyaninato ligands, which are stabilized by electron-donating n-butoxy groups. From X-ray structural analyses, all the complexes become axially compressed upon ligand oxidation, resulting in bowl-shaped distortions of the ligands. In addition, unusual coexistence of square antiprism and square prism geometries around metal ions was observed in +4e charged species.

Neutral Organic Radical Formation by Chemisorption on Metal Surfaces.

Organic radical monolayers (r-MLs) bonded to metal surfaces are potential materials for the development of molecular (spin)electronics. Typically, stable radicals bearing surface anchoring groups are used to generate r-MLs. Following a recent theoretical proposal based on a model system, we report the first experimental realization of a metal surface-induced r-ML, where a rationally chosen closed-shell precursor 3,5-dichloro-4-[bis(2,4,6-trichlorophenyl)methylen]cyclohexa-2,5-dien-1-one () transforms into a stable neutral open-shell species () via chemisorption on the Ag(111) surface.

Tailoring Magnetic Features in Zigzag-Edged Nanographenes by Controlled Diels-Alder Reactions.

Nanographenes (NGs) with tunable electronic and magnetic properties have attracted enormous attention in the realm of carbon-based nanoelectronics. In particular, NGs with biradical character at the ground state are promising building units for molecular spintronics. However, most of the biradicaloids are susceptible to oxidation under ambient conditions and photolytic degradation, which hamper their further applications.

Buchwald-Hartwig Coupling at the Naphthalenediimide Core: Access to Dendritic, Panchromatic NIR Absorbers with Exceptionally Low Band Gap.

The first successful Buchwald-Hartwig reaction at the naphthalenediimide core is reported, leading to the coupling of diverse secondary aromatic amines including dendritic donors. The G1-dendrimer-based donor exhibit blackish color, providing access to black absorbing systems. λ values up to 1070 nm was achieved, which is the maximum from a single NDI scaffold.

Toward Full Zigzag-Edged Nanographenes: peri-Tetracene and Its Corresponding Circumanthracene.

Zigzag-edged nanographene with two rows of fused linear acenes, called as n- peri-acene (n-PA), is considered as a potential building unit in the arena of organic electronics. n-PAs with four ( peri-tetracene, 4-PA), five ( peri-pentacene, 5-PA) or more benzene rings in a row have been predicted to show open-shell character, which would be attractive for the development of unprecedented molecular spintronics. However, solution-based synthesis of open-shell n-PA has thus far not been successful because of the poor chemical stability.

Isolated parapharyngeal cold abscess in a 9-year-old boy.

Tuberculous adenitis presenting as an isolated cold abscess in the parapharyngeal space is very uncommon and has not been reported in the paediatric age group; presentation as a retropharyngeal abscess, however, is well known. Nine-year-old boy with a progressively increasing swelling on the right side of the neck for 2 months was referred with a clinical diagnosis of neuroblastoma. Surgical exploration of the parapharyngeal space by needle aspiration yielded a cheesy material and Mycobacterium tuberculosis was detected by DNA TB PCR.

Electron sponge from naphthalenediimide-viologen conjugates: water-stable, highly electron-deficient polyions with 1 V potential window.

We report a new class of multi-electron acceptors by integrating for the first time multiple π-cations at the naphthalenediimide-core. These polyions present a remarkably low-lying LUMO with water stability, seven-redox states in a narrow window of ∼1 V and excellent reversibility. Extended conjugation is manifest in mixed valence states with NIR absorption.

A surface confined yttrium(iii) bis-phthalocyaninato complex: a colourful switch controlled by electrons.

SAMs of a Y(iii) double-decker complex on ITO have been prepared and their electrical and optical properties explored, exhibiting three accessible stable redox states with characteristic absorption bands in the visible spectra, corresponding to three complementary colors (, green, blue and red). These absorption bands are exploited as output signals of this robust ternary electrochemical switch, behaving hence as an electrochromic molecular-based device.

Assorted morphosynthesis: access to multi-faceted nano-architectures from a super-responsive dual π-functional amphiphilic construct.

An electronically segmented amphiphile was created by conjugating two π-functional units hydroxyquinoline and naphthalenediimide (HQ/NDI) for the first time. The differential electrostatic potential of the π-surfaces, H-bonding units, etc. trigger a manifold response and direct the assembly of a unique collection of seven diverse nano-architectures.

Norepinephrine-induced apoptotic and hypertrophic responses in H9c2 cardiac myoblasts are characterized by different repertoire of reactive oxygen species generation.

Despite recent advances, the role of ROS in mediating hypertrophic and apoptotic responses in cardiac myocytes elicited by norepinephrine (NE) is rather poorly understood. We demonstrate through our experiments that H9c2 cardiac myoblasts treated with 2 µM NE (hypertrophic dose) generate DCFH-DA positive ROS only for 2h; while those treated with 100 µM NE (apoptotic dose) sustains generation for 48 h, followed by apoptosis. Though the levels of DCFH fluorescence were comparable at early time points in the two treatment sets, its quenching by DPI, catalase and MnTmPyP suggested the existence of a different repertoire of ROS.

Extraordinary stability of naphthalenediimide radical ion and its ultra-electron-deficient precursor: strategic role of the phosphonium group.

Stabilization of radical ions and highly electron-deficient systems under ambient conditions is of great significance. A new design concept is presented that applies the multifaceted features of the phosphonium group to achieve isolation of (a) the first naphthalenediimide (NDI) radical ion [(1a•+)BPh4(–)] as single crystals and (b) an ultra-electron-deficient NDI [(1a(2+))2BF4(–)] having the lowest LUMO level recorded for an NDI, overwhelming the formative tetracyanoquinodimethane (TCNQ) molecule. Both 1a•+ and 1a(2+) exhibit unprecedented stability to normal workup procedures, chromatography, and anion metathesis in open air.

A tetrastable naphthalenediimide: anion induced charge transfer, single and double electron transfer for combinational logic gates.

Herein we demonstrate the formation of the first tetrastable naphthalenediimide (NDI, 1a) molecule having multiple distinctly readable outputs. Differential response of 1a to fluoride anions induces intramolecular charge transfer (ICT), single/double electron transfer (SET/DET) leading to a set of combinational logic gates for the first time with a NDI moiety.

Single electron transfer-driven multi-dimensional signal read-out function of TCNQ as an "off-the-shelf" detector for cyanide.

Herein we report the first applications of TCNQ as a rapid and highly sensitive off-the-shelf cyanide detector. As a proof-of-concept, we have applied a kinetically selective single-electron transfer (SET) from cyanide to deep-lying LUMO orbitals of TCNQ to generate a persistently stable radical anion (TCNQ(•-)), under ambient condition. In contrast to the known cyanide sensors that operate with limited signal outputs, TCNQ(•-) offers a unique multiple signaling platform.

Core-modified naphthalenediimides generate persistent radical anion and cation: new panchromatic NIR probes.

The generation of the first persistent radical cation of naphthalenediimide with Cu(2+)/Fe(3+) under ambient conditions is reported. An alternate anionic trigger generates a persistent radical anion within the same motif. Steric protection and H-bonding enhances the half-life of radical cation by 290-fold.

NTCDA-TTF first axial fusion: emergent panchromatic, NIR optical, multi-state redox and high optical contrast photooxidation.

The first synthetic entry into axially fused NTCDA/PMDA-TTF multipolar molecules demonstrates a high optical contrast photooxidation, panchromism, low HOMO-LUMO gap, generation of a stable radical cation, NIR absorption/emission beyond 2150/800 nm and theoretically calculated NLO activity.

Single-electron transfer driven cyanide sensing: a new multimodal approach.

A new SET-driven reaction-based strategy is reported for sensing of cyanide with indicators having low LUMO levels. The cyanide-specific reaction produces an air-stable radical anion marker and by virtue of its spin, charge, and the SOMO-LUMO-based electronic transition generates multimodal signal outputs. High selectivity and sensitivity (0.

Naphthalene-bis-hydrazimide: radical anions and ICT as new bimodal probes for differential sensing of a library of amines.

A new strategy of a bimodal sensing for amines and the first applications of radical anions as probes to colorimetrically differentiate a library of amines is reported.