Bottom-Up Porous Graphene Synthesis and its Applications.

Incorporation of regular order pores/holes/defects into semimetalic graphene sheets can tune the band gap up to 1 eV or more introducing semiconducting property and therefore exhibiting promising applications for organic electronics such as field-effect transistors (FETs), molecular sieve membranes, gas sensing, catalysis devices, etc. In this mini review, we focused on bottom-up approaches to introduce periodic homogeneous pores into graphene and nanographene and graphene nanoribbons along with their characteristics and potential applications in various fields.

Bottom-Up Synthesis of Twisted Porous Graphene through a Heterogeneous Scholl Reaction and Its Supercapacitor Application.

Anthracene- and pyrene-based twisted porous graphene () with an ordered pore structure has been synthesized through bottom-up solution phase synthesis from a conjugated microporous polymer () via a heterogeneous Scholl cyclization reaction. The regular-ordered pores embedded within the graphene structures were analyzed through a Raman spectrum, different morphological analyses, and theoretical studies. A significant change in surface area from to was observed, from 143 to 640 m/g, respectively.

Easy Access to Sauropunols A-D: Synthesis and Spectroscopy Correlation of Their Natural Methyl and Ethyl Glycosides.

3,6-Anhydro-2-deoxy-hexofuranoside, the natural product core, is present in natural sauropunols (A-D) and in their natural methyl and ethyl glycosides, now, namely, sauropunol H and sauropunol F. The easily synthesized d-glucose-derived 3,6-anhydro-1,2--isopropylidene-5--benzoyl-α-d-glucofuranose was elaborated to final targets employing the TsOH·HO-catalyzed glycosylation reaction with seven different alcohols, subsequent radical deoxygenation, and appropriate deprotection reactions involving mild conditions with excellent functional group tolerance. A short total synthesis of sauropunols (A-D), sauropunol H, and the first total synthesis of sauropunol F are reported herein.

Modulation of amyloid fibrillation of bovine β-lactoglobulin by selective methionine oxidation.

Deposition of oxidation-modified proteins during normal aging and oxidative stress are directly associated with systemic amyloidoses. Methionine (Met) is believed to be one of the most readily oxidisable amino acid residues of protein. Bovine beta-lactoglobulin (β-lg), a model globular whey protein, has been presented as a subsequent paradigm for studies on protein aggregation and amyloid formation.

Efficacious Electrochemical Oxygen Evolution from a Novel Co(II) Porphyrin/Pyrene-Based Conjugated Microporous Polymer.

Oxygen evolution reaction (OER) is energetically challenging from the platform of making many photovoltaic devices such as metal-air batteries and water splitting systems because of its poor kinetics even when precious metals are used. Herein, a Co(II)-porphyrin/pyrene-comprised conjugated microporous polymer Co-MPPy-1 has been developed which shows efficient OER in alkaline medium. The material was characterized by Fourier transform infrared, solid-state C cross-polarization magic angle spinning nuclear magnetic resonance, N volumetric adsorption/desorption analysis, scanning electron microscopy, ultra high resolution-transmission electron microscopy, X-ray photoelectron spectroscopy, and other physical studies.

A conjugated microporous polymer based visual sensing platform for aminoglycoside antibiotics in water.

A donor-acceptor based conjugated microporous polymer, PER@NiP-CMOP-1, has been synthesized which can achieve highly sensitive stereo-specific "Turn ON" biosensing of an aminoglycoside up to the ppb level. The coordination-driven inhibition of photo-induced electron transfer (d-PET) for d-electrons and the rotational freezing are the key factors for the recovery of the emission.

A new strongly paramagnetic cerium-containing microporous MOF for CO fixation under ambient conditions.

Metal organic frameworks (MOFs) bearing multicarboxylate linkers are in great demand for designing robust heterogeneous catalysts. A new microporous Ce(iii)-based metal organic framework (CeNDC) has been synthesized under solvothermal conditions, which showed strong paramagnetism and a CO uptake capacity of 1.64 mmol g (7.

Electrochemical Stimuli-Driven Facile Metal-Free Hydrogen Evolution from Pyrene-Porphyrin-Based Crystalline Covalent Organic Framework.

A [2 + 2] Schiff base type condensation between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAP) and 1,3,6,8-tetrakis (4-formylphenyl) pyrene (TFFPy) under solvothermal condition yields a crystalline, quasi-two-dimensional covalent organic framework (SB-PORPy-COF). The porphyrin and pyrene units are alternatively occupied in the vertex of 3D triclinic crystal having permanent microporosity with moderately high surface area (∼869 m g) and promising chemical stability. The AA stacking of the monolayers give a pyrene bridged conducting channel.

Fused Helicene Chains: Towards Twisted Graphene Nanoribbons.

By taking advantage of an unexpected regioselectivity of intramolecular Scholl reactions on pentaphenylene compounds that favors distorted [5]helicenes over their flat counterparts, a new synthetic approach to twisted graphene nanoribbons has been designed based on side-fused di-tert-butyl-[5]helicene fragments. Syntheses of both small monomers and dimers have been achieved and their structures have been studied. An iterative synthetic strategy has been developed for the formation of longer flexible precursors, which relies on the step-by-step elongation of mono-functionalized oligomeric chains.

Smokeless tobacco consumption impedes metabolic, cellular, apoptotic and systemic stress pattern: A study on Government employees in Kolkata, India.

Smokeless tobacco (SLT) remains a threat amongst a large population across the globe and particularly in India. The oral use of tobacco has been implicated to cause physiological stress leading to extreme toxicological challenge. The study included 47 SLT-users and 44 non-users providing a spectrum of pathophysiological, clinico-biochemical, antioxidant parameters, cell cycle progression study of PBMC and morphological changes of red blood cells (RBC).

Helicenes from diarylmaleimides.

Perkin condensations of arylglyoxylic acids with arylacetic acids, followed by the addition of alkylamine, yield diarylmaleimides in a one-pot procedure. The arylglyoxylic acids are obtained by arene acylation with ClCOCO2Et and reduced with NaI and hypophosphorous acid to the arylacetic acids. With 2,7-di-tert-butyl-pyren-4-yl or chrysen-6-yl as the aryl, photocyclodehydrogenation of the diarylmaleimides yields substituted helicenes which can be reduced to stable anions.

Twisted polycyclic arenes by intramolecular Scholl reactions of C3-symmetric precursors.

With the aim of opening an efficient access to large and sterically crowded polycyclic arenes as well as improving insight into the geometrical preferences of the Scholl reaction, a versatile synthesis strategy has been developed to form a family of flexible yet strongly crowded substrates for multiple dehydrocyclizations. Their intramolecular Scholl reactions lead with high selectivity either to considerably twisted species where the initial C3 symmetry is maintained, or to strongly rearranged products where the formation of multiple [6]helicene fragments is avoided by the formation of unusual hexa[7]circulene moieties under loss of the C3 symmetry.

Highly twisted arenes by Scholl cyclizations with unexpected regioselectivity.

Let's twist! The Scholl reaction with quinquephenyl derivatives has been shown to have an unexpectedly strong preference for forming twisted, helicene aromatic polycycles, instead of their flat counterparts. This tendency is so strong that it will overcome even severe steric hindrance, and the procedure can be used in the efficient synthesis of hexa-tert-butylhexabenzotriphenylene from a simple biaryl starting material (see scheme).