Unexpected benzene oxidation in collisions with superoxide anions

Superoxide anions colliding with benzene molecules at impact energies from 200 to 900 eV are reported for the first time to form massive complexes. With the aid of quantum chemistry calculations, we propose a mechanism in which a sudden double ionization of benzene and the subsequent electrostatic attraction between the dication and the anion form a stable covalently bonded C6H6O2+ molecule, that evolves towards the formation of benzene-diol conformers. These findings lend support to a model presenting a new high energy anion-driven chemistry as an alternative way to form complex molecules.

Electro-mediated PhotoRedox Catalysis for Selective C(sp3)-O Cleavages of Phosphinates to Carbanions

We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp³)-O bonds of phosphinates to alkyl carbanions. As well as deoxygenations, olefinations are reported which are <i>E</i>-selective and can be made <i>Z</i>-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for a more intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp³)-O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions i) tolerate aryl chlorides/bromides and ii) do not give rise to Birch-type reductions.

Electro-mediated PhotoRedox Catalysis for Selective C(sp3)-O Cleavages of Phosphinates to Carbanions

We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp³)-O bonds of phosphinates to alkyl carbanions. As well as deoxygenations, olefinations are reported which are <i>E</i>-selective and can be made <i>Z</i>-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for a more intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp³)-O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions i) tolerate aryl chlorides/bromides and ii) do not give rise to Birch-type reductions.

Unveiling Extreme Photoreduction Potentials of Donor-Acceptor Cyanoarenes to Access Aryl Radicals from Aryl Chlorides

Since the seminal work of Zhang in 2016, donor-acceptor cyanoarene-based fluorophores, such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN), have been widely applied in photoredox catalysis, and used as excellent metal-free alternatives to noble metal Ir- and Ru-based photocatalysts. However, all the reported photoredox reactions involving this chromophore family are based on harnessing the energy from a single visible light photon, with a limited range of redox potentials from -1.92 V to +1.79 V. Here, we document the unprecedented discovery that this family of fluorophores can undergo consecutive photoinduced electron transfer (ConPET) to achieve very high reduction potentials. One of the newly synthesized catalysts, 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN), possesses a long-lived (12.95 ns) excited radical anion form, 3CzEPAIPN^•⁻*, which can be used to activate reductively recalcitrant aryl chlorides (E_red≈ -1.9 to -2.9 V) under mild conditions. The resultant aryl radicals can be engaged in synthetically valuable aromatic C-B, C-P, and C-C bond formation to furnish arylboronates, arylphosphonium salts, arylphosphonates, and spirocyclic cyclohexadienes, respectively.

Unveiling Extreme Photoreduction Potentials of Donor-Acceptor Cyanoarenes to Access Aryl Radicals from Aryl Chlorides

Since the seminal work of Zhang in 2016, donor-acceptor cyanoarene-based fluorophores, such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN), have been widely applied in photoredox catalysis, and used as excellent metal-free alternatives to noble metal Ir- and Ru-based photocatalysts. However, all the reported photoredox reactions involving this chromophore family are based on harnessing the energy from a single visible light photon, with a limited range of redox potentials from -1.92 V to +1.79 V. Here, we document the unprecedented discovery that this family of fluorophores can undergo consecutive photoinduced electron transfer (ConPET) to achieve very high reduction potentials. One of the newly synthesized catalysts, 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN), possesses a long-lived (12.95 ns) excited radical anion form, 3CzEPAIPN^•⁻*, which can be used to activate reductively recalcitrant aryl chlorides (E_red≈ -1.9 to -2.9 V) under mild conditions. The resultant aryl radicals can be engaged in synthetically valuable aromatic C-B, C-P, and C-C bond formation to furnish arylboronates, arylphosphonium salts, arylphosphonates, and spirocyclic cyclohexadienes, respectively.

Generation of a Hetero Spin Complex from Iron(II) Iodide with Redox Active Acenaphthene-1,2-Diimine

The reaction of the redox active 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) and iron(II) iodide in acetonitrile led to a new complex [(dpp-BIAN)FeIII2] (1). Molecular structure of 1 was determined by the single crystal X-ray diffraction analysis. The spin state of the iron cation in complex 1 at room temperature and the magnetic behavior of 1 in the temperature range of 2–300 K were studied using Mossbauer spectroscopy and magnetic susceptibility measurements, respectively. The neutral character of dpp-BIAN in 1 was confirmed by IR and UV spectroscopy. The electrochemistry of 1 was studied in solution and solid state using cyclic voltammetry. The generation of the radical anion form of the dpp-BIAN ligand upon reduction of 1 in a CH2Cl2 solution was monitored by EPR spectroscopy.

Improve pineapples growth by nano-membranes accessory and under stress condition in far north of Taiwan

<abstract> <p>The dual layers of Nano-membranes barrier, could succeeded in regulation nutrient element and control water-borne disease by improving aerations through added dual layers of nano-membranes, this plantation model provide concept of providing hydrophilic properties and 500 nm pore size believed to be much precision tools for agricultural utilization. This rebuilding of pineapple cultivation was optimized in green-house with natural ventilation, Optimized humidity and free watering were properly practiced by implement of diffusion cage for a novel revealed boundary effect by 500 nm mold inject product. Effect indicated as indicated: Cellulose, PBT, CTA in sequence have better boundary effects over limiting the diffusion of nitrate, phosphate, and a small part of potassium in the root boundary regime through proper moisture with 0.5–0.8 L/pot button irrigation, The intensity of boundary effect were revealed in kinetic analysis follow in sequence: EC (1500 mg L⁻¹) &gt; &gt; nitrate (300 mg L⁻¹) &gt; TPO (2.5 mg L⁻¹), while highly fluctuate for TPO. Then indication of hydrophilic PBT was better than PP was verified in barrier model. In the growth stage, separate initial I–III for direct releasing from the fertilizer and III–VI for hydrolysis &amp; secretion of nutrient, especially for TPO anion form, indicate highly ion charged or polar attraction exerted. While phosphate was delivered slowly, the organic practice was found promising in deliver and uptake to the final two or three stage for flowering and fruiting. The verification of deliver of nutrient by double caged box in the rhigime zone, indicated effective in lowered the damping off/nematode syndrome, which opened the extension cropping in suboptimal area for pineapples. The success of growth character improved by control disease and pest, reach complete maturation. Under 80 % of final fruiting, the balance analysis show consistence in expectation for Pya (wild) &gt; Pyc (hybrid) &gt; Pyb (interbreed).</p> </abstract>

Cd(H2O)2[C6H3(COO)2(COOH)] - A Two-Dimensional Coordination Polymer with Cationexchanger Features

Monoclinic single crystals of Cd(H2O)2[C6H3(COO)2(COOH)] have been prepared in aqueoussolution at 80 °C. Space group C2/c (no. 15), a = 1973.0(2), b = 910.74(7), c = 1336.81(10)pm, β = 117.897(8)°, V = 2.1230(3) nm3, Z = 8. Cd2+ is coordinated in a moderately distortedpentagonal bipyramidal fashion by five oxygen atoms stemming from themonohydrogentrimesinate anions in the equatorial plane and two water molecules in theapical positions (Cd–O 224.0(2) – 255.0(2) pm). The connection of Cd2+ with[C6H3(COO)2(COOH)]2− yields a two-dimensional coordination polymer. The atoms of themonohydrogentrimesinate anion form in good approximation a common plane.Thermogravimetric analysis in air shows that the dehydrated compound is stable up to 390°C. Further decomposition yields CdO.

Crystal structure of fac-bis[bis(pyridin-2-yl)methanamine]iron(II) 1,1,3,3-tetracyano-2-(dicyanomethylidene)propane-1,3-diide, [Fe(dipa)2](tcpd)

In the title compound, [Fe(C11H11N3)2](C10N6), the FeII cation is coordinated by two bis(pyridin-2-yl)methanamine (dipa) ligands and has crystallographic twofold symmetry. There are deviations from ideal octahedral geometry due to the steric requirements of the ligands. The polynitrile 1,1,3,3-tetracyano-2-(dicyanomethylidene)propane-1,3-diide (tcpd2−) dianion is disordered about an inversion center and is not coordinated to the Fe atom. The anion is not planar but has a propeller shape. In the crystal, weak N—H...N interactions between the amine H atoms of the dipa ligands and two nitrile groups of the anion form an alternating chain of cations and anions related by the C-centering of the unit cell.

Crystal structure of 4-benzylcarbamoyl-1-methylpyridin-1-ium iodide: an efficient multimodal antiviral drug

In the title compound, [MeC5H4NCONHCH2C6H5]I or C14H15N2O+·I−, a cation and an anion form an ionic pair linked by a strong N—H...I hydrogen bond. In the crystal, ionic pairs linked by weak C—H...I hydrogen bonds form infinite ribbons along the crystallographicaaxis. Polymorphism screening varying crystallization solvents (water, acetone 90%–water, ethanol 90%–water, 2-propanol 90%–water, DMF, DMSO, methanol, acetonitrile) and conditions (solution temperature, heating and cooling protocols) did not reveal any other polymorphs than the one reported in this work.