290-96-0Relevant articles and documents
MR3-substituted alkynes 2 and 3 (M = Si, Ge, Sn; R = alkyl) show high reactivity in inverse-type Diels-Alder reactions with the re-electron-deficient 1,2,4,5-tetrazine 1 in strict contrast to the corresponding carbon compounds.
Heldmann, Dieter K.,Sauer, Juergen
, p. 5791 - 5794 (1997)
MR3-substituted alkynes 2 and 3 (M = Si, Ge, Sn; R = alkyl) show high reactivity in inverse-type Diels-Alder reactions with the re-electron-deficient 1,2,4,5-tetrazine 1 in strict contrast to the corresponding carbon compounds. Kinetic data prove the huge accelerating effect of the trialkyltin substituent, offering a simple access to new heteroaromatic organotin derivatives, which can be easily transformed by standard methods of organotin chemistry.
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Spencer et al.
, p. 1925,1926,1928-1930 (1961)
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Tailoring Dihydroxyphthalazines to Enable Their Stable and Efficient Use in the Catholyte of Aqueous Redox Flow Batteries
Hofmann, Jonas D.,Hong, Longcheng,Janek, Jürgen,Mollenhauer, Doreen,Schmalisch, Sebastian,Schr?der, Daniel,Schwan, Sebastian,Wegner, Hermann A.
, p. 3427 - 3438 (2021/06/14)
To enable cost-efficient stationary energy storage, organic active materials are the subject of current investigations with regard to their application in aqueous redox flow batteries. Especially quinones with their beneficial electrochemical properties and natural abundance pose a promising class of compounds for this challenging endeavor. Yet, there are not many active materials available for the catholyte side to realize solely quinone-based systems. Herein we introduce the novel hydroquinone 5,8-dihydroxy-2,3-phthalazine together with two of its derivatives and propose it as a promising active material for the catholyte side of aqueous redox flow batteries. We systematically investigate the electrochemical properties as well as the structure-property relationship of this class of compounds. The unmodified dihydroxyphthalazine exhibits a favorably high redox potential of 796 mV vs SHE in acidic solution that is competitive with benzoquinone compounds. Moreover, the introduced dihydroxyphthalazines feature a high electron transfer rate surpassing benzoquinone species by almost one order of magnitude. With regard to stable cycling performance, we further achieved a high resilience against detrimental side reactions such as Michael addition by adding methyl substituents to the base structure. Our experimental findings are supported and extended by theoretical considerations in terms of density functional theory calculations. With this combined approach we outline further promising dihydroxyphthalazine-based materials with regard to performance-relevant quantities like redox potential, cycling stability, and water solubility. This study aims to propel further research in the field of quinone-based active materials for the catholyte of future aqueous redox flow batteries.
INHIBITORS OF POLO-LIKE KINASE
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Page/Page column 315, (2012/04/23)
The present invention provides compounds having a structure according to Formula (I):or a salt or solvate thereof, wherein ring A, U1, U2, U3, R2, R3 and R4 are defined herein. The invention further provides pharmaceutical compositions including the compounds of the invention and methods of making and using the compounds and compositions of the invention, e.g., in the treatment and prevention of various disorders, such as Parkinson's disease.
Copper(I) and silver(I) coordination frameworks involving extended bipyridazine bridges
Degtyarenko, Anna S.,Solntsev, Pavlo V.,Krautscheid, Harald,Rusanov, Eduard B.,Chernega, Alexander N.,Domasevitch, Konstantin V.
supporting information; experimental part, p. 1910 - 1918 (2009/02/07)
1,4-(Pyridazin-4-yl)benzene (bpph), a new N-donor tetradentate ligand, was prepared by inverse electron demand cycloaddition reacting 1,4-diethynylbenzene and 1,2,4,5-tetrazine. In combination with Cu(i) and Ag(i) ions, it affords coordination framework topologies that were dominated by assembly of dinuclear metal-pyridazine "secondary building blocks" [M2(μ-pdz) 2] supporting further polymeric connectivity. In structures [Cu 2(bpph)(CH3CN)2{S2O6}] (1) and [Ag6(bpph)3(H2O)6{C 6H4(COO)2}2]C6H 4(COO)2·4H2O (8) interconnection of the dinuclear nodes occurs with anionic dithionate and isophthalate bridges, while [Ag2(bpph){C6H5CO2} 2]·2H2O (7) adopts a linear chain structure incorporating disilver(i) pyridazine units and terminal benzoate anions. [Cu4(bpph)5](BF4)4·4CHCl 3 (2) has a 3D supramolecular structure involving polycatenation of the 2D "bilayer" metal-organic topologies built up of five-connected dinuclear nodes. Frameworks of [Ag(bpph){NO3}]·CHCl 3 (3) and [Ag(bpph){C2F5COO}] (5) exist as 2D square-grids nets supported with sets of tetra- and bidentate bipyridazine bridges, while closely related [Ag4(bpph)3{CF 3COO}4]·CH3CN (4) is a 1D "ladder" polymer. The three-fold interpenetrated 3D diamondoid framework of [Ag4(bpph)3{CH3SO 3}4]·2CHCl3 (6) was based upon more complicated tetranuclear nodes [Ag4(μ-pdz)4(pdz) 2]. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2008.
