Synthesis of (E)-nitroolefins via decarboxylative nitration using t-butylnitrite (t-BuONO) and TEMPO.

Nitroolefins are usually synthesized using the Henry reaction. Here we report an alternative metal-free decarboxylative nitration protocol for the preparation of the nitroolefins from α,β-unsaturated carboxylic acids using t-butylnitrite (t-BuONO) and TEMPO. α,β-Unsaturated carboxylic acids bearing β-aromatic and β-heteroaromatic substituents gave (E)-nitroolefins exclusively under mild conditions. A radical based pathway has been proposed for this decarboxylative nitration reaction

Pure white light emission and charge transfer in organogels of symmetrical and unsymmetrical π-chromophoric oligo-p-(phenyleneethynylene) bola-amphiphiles

Two novel bola-amphiphilic oligo-p-(phenyleneethynylene) (OPE) dicarboxylates have been synthesized having non-polar and mixed-polar side chains. This led to gelation in both with vesicular morphology. Upon in situ loading of a suitable dye and redox-active molecule, pure white light emitting and charge transfer (CT)-gels, respectively, were realized

Three photon absorbing photocatalyst enabled defluorinative amination of fluoroarenes

We have developed a photocatalytic system that explores the latent potential of a new photocatalyst HATCN. The architecture of this flat molecule is well poised to pose it as a great photooxidant, that can also afford multiple redox states. The excited reduction potential of HATCN is calculated as 2.83 V which corroborates well with its strong oxidizing behavior. A large number of SNAr reactions have been conducted over a wide variety of fluororenes with varying electronic nature. The catalytic efficiency of the photocatalyst has been demonstrated by successful reaction to both electron-neutral and -poor fluoroarenes. Furthermore, the great utility of this developed protocol has been established by applying this method over a large number of building blocks of drugs and pharmaceutically important moieties. An extensive studies delineate the involvement of three photons for one catalytic cycle, that is unprecedented in photocatalysis. Furthermore, the redox modularity of the photocatalyst gives access to the oxidant and reductant behavior of the same molecule at different stages of the catalytic cycle. This discovery of novel mechanistic paradigm will translate in solving challenging photochemical processes

Nanovesicular MOF with Omniphilic Porosity: Bimodal Functionality for White-Light Emission and Photocatalysis by Dye Encapsulation

A new π-chromophoric and asymmetric bola-amphiphilic oligo-(<i>p</i>-phenylene ethynylene)-based tetracarboxylate (<b>OPE-TC1</b>) linker was designed, synthesized, and self-assembled with Zn­(OAc)₂. The resulting nanoscale metal–organic framework (MOF) {Zn₂(<b>OPE-TC1</b>)}<i>_n</i> (<b>NMOF-1</b>) showed a vesicular morphology and permanent porosity with omniphilic pore surface. <b>NMOF-1</b> showed cyan emission with high quantum efficiency (49%). The omniphilicity of the pore was utilized to incorporate ambipolar dye sulforhodamine G (<b>SRG</b>) to tune the band gap as well as to get pure white-light emission. Furthermore, the polar pore surface of <b>NMOF-1</b> allowed facile diffusion of the substrate for efficient photocatalytic activity. The dye-encapsulated framework further showed enhanced dihydrogen production by 1.75-fold compared to that from the as-synthesized <b>NMOF-1</b> because of the modulated band gap and high excited state lifetime. As a control experiment, we have synthesized a MOF (<b>MOF-OMe</b>) with an <b>OPE-TC2</b> linker having −OMe functional groups that did not show nanoscale architecture. This suggested the important role of unsymmetrical bola-amphiphilicity in nanostructuring. This rational design of a chromophoric linker resulted in a nanoscale MOF with omniphilic porosity to achieve bimodal functionality in clean energy applications

Excitation Energy Transfer Supported Amplified Charge-Transfer Emission in an Anthracenedicarboxylate- and Bipyridophenazine-Based Coordination Complex

A highly luminescent tetrameric zinc­(II) complex, {[Zn₄(adc)₃(bpz)₆(HCOO)₂]·2H₂O} (<b>1</b>; adc = 9,10-anthracenedicarboxylate and bpz = bipyridophenazine), was synthesized by a solvothermal technique and characterized by single-crystal X-ray diffraction. The linear tetrameric units extend into three dimensions via π stacking of adc/bpz and bpz/bpz and multiple CH−π interactions. The compound shows strong red emission at 597 nm (λ_ex = 480 nm), which is attributed to charge-transfer (CT) emission within an adc/bpz donor–acceptor pair. This is also supported by density functional theory computations. Interestingly, the CT emission is amplified by energy transfer from another adc linker that is not involved in the CT interaction