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Usage

Uses

Used in General Weed Control:
Diquat dibromide is used as a general weed control agent on noncrop land. It is effective in controlling a wide range of broad-leaved weeds and grasses.
Used in Preharvest Desiccation:
Diquat dibromide is used as a preharvest desiccant on crops such as cotton, flax, and alfalfa. It helps to speed up the drying process, making it easier to harvest the crops.
Used in Aquatic Weed Control:
Almost one-third of all Diquat dibromide sold is used to control emergent and subemergent aquatic weeds. It is effective in managing unwanted plant growth in water bodies.
Used in Fruit and Vegetable Crops:
Diquat dibromide is used as a nonselective contact herbicide to control broad-leaved weeds in fruit and vegetable crops. This helps to protect the crops from competition and improve yield quality.
Used in Herbicidal Desiccant:
Diquat dibromide is also used as a herbicidal desiccant, which helps to dry out and kill unwanted plants, making it easier to manage and control vegetation in various settings.

Health Hazard

The acute toxicity of diquat dibromide ismoderate to high in most species. In domes-tic animals, its toxicity is greater than thatin small laboratory animals. The oral LD50value in cows, dogs, rabbits, and mice is30, 187, 188, and 233 mg/kg, respectively.The symptoms of acute toxicity are somnolence, lethargy, pupillary dilation, and respiratory distress. Prolonged exposure to thiscompound produced cataracts in experimental animals. Intratracheal administration ofdiquat dibromide in rats showed toxic effectsin the lung and caused lung damage (Manabeand Ogata 1986). But when administered byoral or intravenous routes, there was no toxiceffect on the lung.

Flammability and Explosibility

Notclassified

Safety Profile

Poison by ingestion, subcutaneous, intravenous, and intraperitoneal routes. Experimental teratogenic and reproductive effects. A skin and eye irritant. Human mutation data reported. When heated to decomposition it emits very toxic fumes of NOx, and Br-. See also PARAQUAT

Environmental Fate

Biological. Under aerobic and anaerobic conditions, the rate of diquat mineralization in eutrophic water and sediments was very low. After 65 days, only 0.88 and 0.21% of the applied amount (5 μg/mL) evolved as carbon dioxide (Simsiman and Chesters, 1976). Diquat is readily mineralized to carbon dioxide in nutrient solutions containing microorganisms. The addition of montmorillonite clay in an amount equal to adsorb one-half of the diquat decreased the amount of carbon dioxide by 50%. Additions of kaolinite clay had no effect on the amount of diquat degraded by microorganisms (Weber and Coble, 1968).Photolytic. Diquat has an absorption maximum of 310 nm (Slade and Smith, 1967). The sunlight irradiation of a diquat solution (0.4 mg/100 mL) yielded 1,2,3,4-tetrahydro1-oxopyrido[1,2-a]-5-pyrazinium chloride (TOPPS) as the principal metabolite.Chemical/Physical. Decomposes at 320°C (Windholz et al., 1983) emitting toxic fumes of bromides and nitrogen oxides (Lewis, 1990). Diquat absorbs water forming wellde?ned, pale yellow crystalline hydrate (Calderbank and Slade, 1976).In aqueous alkaline solutions, diquat decomposes forming complex colored products including small amounts of dipyridone (Calderbank and Slade, 1976).

Toxicity evaluation

DQ is a dipyridyl compound that is capable of redox cycling. DQ can become reduced to produce a free radical. It can then transfer this electron to molecular oxygen to yield superoxide anion. This redox cycling mechanism allows DQ to generate reactive oxygen species (ROS) resulting in oxidative stress, damage to cellular macromolecules and even cell death. Due to its standard redox potential (E0), DQ is more likely to accept an electron compared to paraquat. Because of this property, DQ is expected to generate greater amounts of ROS compared to paraquat at equivalent concentrations. In vitro studies have shown that DQ is dependent on mitochondrial complex I and III in isolated mitochondria and primarily complex III in midbrain neuronal cultures for ROS production. DQ treatment can lead to NADPH depletion, lipid peroxidation, alteration in intracellular redox status, and liberation of ferritin-bound iron stores.

InChI:InChI=1/C12H12N2.2BrH/c1-3-7-13-9-10-14-8-4-2-6-12(14)11(13)5-1;;/h1-8H,9-10H2;2*1H/q+2;;/p-2

Upstream product

• 366-18-7 [2,2]bipyridinyl 
• 106-93-4 ethylene dibromide 
• 35152-38-6 N-pentylpyrrolidine 
• 110-52-1 1,4-dibromo-butane 

Downstream Products

• 94659-86-6 C₁₂H₁₂N₂⁽²⁺⁾*C₈H₄O₄^(2-) 
• 2764-72-9 6,7-dihydrodipyrido<1,2-a:1',2'-c>pyrazinium radical cation 
• 35022-72-1 diquat dipyridone 
• 94659-85-5 C₁₂H₁₂N₂⁽²⁺⁾*C₈H₄O₄^(2-) 
• 67994-94-9 6,7-Dihydrodipyrido[1,2-a;2',1'-c]pyrazinediium bis(hexafluorophosphate) 
• 4032-26-2 6,7-Dihydrodipyrido<1,2-a:2',1'-c>pyrazinium dichloride 
• 119108-97-3 6,7-dihydropyrido{1,2-a:2',1'-c}pyrazindiium-bis{bis(cis-1,2-diphenyl-1,2-ethenedithiolato)niccolate 

Relevant academic research and scientific papers

Molecular photoconductor with simultaneously photocontrollable localized spins

UV irradiation reversibly switches a new insulating and nonmagnetic molecular crystal, BPY[Ni(dmit)2]2 (BPY = N,N-ethylene-2,2-bipyridinium; Ni(dmit)2 = bis(1,3-dithiole-2-thione- 4,5-dithiolato)nickelate(III)), into a magnetic conductor. This is possible because the bipyridyl derivative cations (BPY2+) trigger a photochemical redox reaction in the crystal to produce a change of ～10% in the filling of the Ni(dmit)2 valence band, leaving localized spins on the BPY themselves. In the dark, almost all of the BPY molecules are closed-shell cations, and most of the Ni(dmit)2 radical anions form spin-singlet pairs; thus, this material is a diamagnetic semiconductor. Under UV irradiation, a photocurrent is observed, which enhances the conductivity by 1 order of magnitude. Electron spin resonance measurements indicate that the UV irradiation reversibly generates carriers and localized spins on the Ni(dmit)2 and the BPY, respectively. This high photoconductivity can be explained by charge transfer (CT) transitions between Ni(dmit)2 and BPY in the UV region. In other words, the photoconduction and "photomagnetism" can be described as reversible optical control of the electronic states between an ionic salt (BPY2+/[Ni(dmit) 2]-, nonmagnetic insulator) and a CT complex (BPY 2(1-δ)+/[Ni(dmit)2](1-δ)- (δ - 0.1), magnetic conductor) in the solid state.

Green Synthesis of Leaning Tower[6]arene-Mediated Gold Nanoparticles for Label-Free Detection

Here a facile synthesis strategy toward carboxylated leaning tower[6]arene (CLT6)-mediated gold nanoparticles (CLT6-AuNPs) without external energy sources and reducing agents has been developed. Due to the cavity structure of CLT6, CLT6-AuNPs with a controllable particle size show good stability and excellent performance in label-free detection of diquat. Significantly, we reveal the reduction mechanism of AuNP formation, which is the cleavage of some phenyl ether bonds of CLT6 to produce reductive phenols, thus reducing Au3+ to AuNPs.

Bipyridinium and Phenanthrolinium Dications for Metal-Free Hydrodefluorination: Distinctive Carbon-Based Reactivity

The development of novel Lewis acids derived from bipyridinium and phenanthrolinium dications is reported. Calculations of Hydride Ion Affinity (HIA) values indicate high carbon-based Lewis acidity at the ortho and para positions. This arises in part from extensive LUMO delocalization across the aromatic backbones. Species [C10H6R2N2CH2CH2]2+ (R=H [1 a]2+, Me [1 f]2+, tBu [1 g]2+), and [C12H4R4N2CH2CH2]2+ (R=H [2 a]2+, Me [2 b]2+) were prepared and evaluated for use in the initiation of hydrodefluorination (HDF) catalysis. Compound [2 a]2+ proved highly effective towards generating catalytically active silylium cations via Lewis acid-mediated hydride abstraction from silane. This enabled the HDF of a range of aryl- and alkyl- substituted sp3(C?F) bonds under mild conditions. The protocol was also adapted to effect the deuterodefluorination of cis-2,4,6-(CF3)3C6H9. The dications are shown to act as hydride acceptors with the isolation of neutral species C16H14N2 (3 a) and C16H10Me4N2 (3 b) and monocationic species [C14H13N2]+ ([4 a]+) and [C18H21N2]+ ([4 b]+). Experimental and computational data provide further support that the dications are initiators in the generation of silylium cations.

Covalent Organic Frameworks Enabling Site Isolation of Viologen-Derived Electron-Transfer Mediators for Stable Photocatalytic Hydrogen Evolution

Electron transfer is the rate-limiting step in photocatalytic water splitting. Viologen and its derivatives are able to act as electron-transfer mediators (ETMs) to facilitate the rapid electron transfer from photosensitizers to active sites. Nevertheless, the electron-transfer ability often suffers from the formation of a stable dipole structure through the coupling between cationic-radical-containing viologen-derived ETMs, by which the electron-transfer process becomes restricted. Herein, cyclic diquats, a kind of viologen-derived ETM, are integrated into a 2,2′-bipyridine-based covalent organic framework (COF) through a post-quaternization reaction. The content and distribution of embedded diquat-ETMs are elaborately controlled, leading to the favorable site-isolated arrangement. The resulting materials integrate the photosensitizing units and ETMs into one system, exhibiting the enhanced hydrogen evolution rate (34600 μmol h?1 g?1) and sustained performances when compared to a single-module COF and a COF/ETM mixture. The integration strategy applied in a 2D COF platform promotes the consecutive electron transfer in photochemical processes through the multi-component cooperation.

Stable Radical Cation-Containing Covalent Organic Frameworks Exhibiting Remarkable Structure-Enhanced Photothermal Conversion

The production of a radical cation-containing covalent organic framework (COF) has been accomplished by sequential in situ reactions, quaternization, and one-electron reduction of the 2,2′-bipyridine-based COFs. The acid-catalyzed COF formation enables the cis configuration of 2,2′-bipyridyl moieties in the structure, of which the stability arises from the eclipsed stacking of the two-dimensional layered structure. The postfunctionalization generates cyclic alkylated diquats as the sole products from the controlled quaternization. The reduction of diquat cations on the COF skeletons results in a large number of radical cations, which delocalize and uniaxially stack on top of one another by virtue of interlayered ?-electronic couplings. The absorption of the near-infrared (NIR) region exhibited by the cationic radical COF is remarkably high owing to the intercharge transfer across the ?-coupling interlayers. Also, the long-range array of extended and planar frameworks in such a COF leads to the extra stability of the radical cations against external stresses. The structure-enhanced performance of the COF material is witnessed with photothermal conversion efficiencies of as high as 63.8 and 55.2% when exposed to 808 and 1064 nm lasers, respectively. Further PEG modification on such a COF allows photoacoustic imaging and photothermal therapy in vivo under NIR light illumination to be manifested.

Tetrachlorocuprate-bipyridyl quaternary ammonium salt and preparation method and application thereof

The invention belongs to the technical field of fine chemosynthesis and particularly relates to a tetrachlorocuprate-bipyridyl quaternary ammonium salt with weeding and antibacterial dual functions. Acompound prepared from tetrachlorocuprate anions and 1,1'-ethylene-2,2'-bipyridyl cations has a chemical structure represented by a formula (I), i.e., shortened for [EtBiPy][CuCl4]. A preparation method of the compound comprises the steps of preparing a 1,1'-ethylene-2,2'-bipyridyl dibromo salt, preparing the tetrachlorocuprate anions and preparing the tetrachlorocuprate-bipyridyl quaternary ammonium salt. The tetrachlorocuprate-bipyridyl quaternary ammonium salt provided by the invention has relatively high antibacterial capability to Staphylococcus aureus and Escherichia coli and also has arelatively good contact poisoning effect on weeds.

Effect of chemical structure of bipyridinium salts as electron carrier on the visible-light induced conversion of CO2 to formic acid with the system consisting of water-soluble zinc porphyrin and formate dehydrogenase

Effect of chemical structures of some 2,2′-bipyridinium salts (BP2+) as the electron carrier molecules on the visible-light induced conversion of CO2 to formic acid with the system consisting of water-soluble zinc tetraphneylporphyrin tetrasulfonate (ZnTPPS) and formate dehydrogenase (FDH) in the presence of triethanolamine (TEOA) as an electron donor molecule was investigated. Irradiation of a CO2 saturated solution containing TEOA, ZnTPPS, BP2+ and FDH with visible light resulted in production of formic acid. By using 1,1′-ethylene-2,2′-bipyridinium dibromide (DB2+) as an electron carrier molecule, the effective formic acid production was observed compared with the other 2,2′-bipyridinium salt derivatives.

Small Crystal ZSM-5, Its Synthesis and Use

A molecular sieve having the framework structure of ZSM-5 is described comprising crystals having an external surface area in excess of 100 m2/g (as determined by the t-plot method for nitrogen physisorption) and a unique X-ray diffraction pattern.

Conversion of solar energy to chemical energy

The rate of evolution of hydrogen from water by photochemical process using solar energy has been investigated employing fourteen metal complexes as catalysts, ten electron relays, three electron donors and two co-catalysts in different permutation and combinations. The effect of varying reaction conditions like temperature, concentration and pH have also been investigated for the optimum production of hydrogen by the photochemical cleavage of water molecules.

Revisiting the IspH catalytic system in the deoxyxylulose phosphate pathway: Achieving high activity

(Chemical Equation Presented) From two C5 isoprene building blocks, isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP), the more than 30000 members of the isoprenoid family are constructed in nature using two biosynthetic pathways, the mevalonate (MVA) pathway and the deoxyxylulose phosphate (DXP) pathway. IspH of the DXP pathway is a protein containing an iron-sulfur cluster and catalyzes a reductive dehydration reaction of the DXP pathway. In the literature, a wide range of Escherichia coli IspH activities have been reported (2.0 nmol min-1 mg-1 to 3.4 μmol min-1 mg-1). For such a broad range of activities, reaction assays were carried out under many different conditions, preventing direct comparison of the activities and determination of the key factor responsible for such a dramatic difference in IspH activities. In this work, we systematically examined the role of redox mediators in IspH catalysis using E. coli IspH as the enzyme and dithionite as the ultimate electron source. Our studies not only suggest the importance of the iron-sulfur cluster but also improve the E. coli IspH activity by nearly 97-fold relative to that from the E. coli NADPH-flavodoxin reductase-flavodoxin system.