Stilbene 4,4 -dinitro

Azo-stilbene dyes formed by condensation of 4,4 -dinitro-2,2 -stilbenedisulfonic acid or 4,4 -dinitro-2,2 -dibenzyldisulfonic acid (1) with aminoazo compounds. Direct Orange 34 (Cl 40215) [32651-66-4] (5) is a representative ... 

Dinitra-sym-diphenyl urea 550 Dinitro stilbene disulphonic 450... 

Titanium ions can also he used as redox catalysts for the indirect cathodic reduction of nitro compounds (417). The electroreduction is carried out in an H20-H2S04/Ti(S04)2-(Pb/Cu) system at 45 80°C under 5 20Am . Nitrobenzene, dinitrobenzene, nitrotoluene, 2,4-dinitrotoluene, 2-nitro-m-xylene, nitro-phenol, 2,4-dinitrophenol, nitrophenetole, o-nitroanisole, 4-nitrochlorotoluene, ni-trobenzenesulfonic acid, and 4,4 -dinitro-stilbene-2,2 -disulfonic acid can all be reduced by this procedure to the corresponding amino compounds (418) in good yields (Scheme 146) [513-516]. Tin... 

Laser flash photolysis (30 ns, 50 mj, 347 nm) of 4-nitrostilbene, 4,4 -dinitro-stilbene, 4-nitro-4 -methoxystilbene and 4-dimethyl-amino-4 -nitrostilbene permits the observation of transients 133) por the latter two compounds, the lifetime and the absorption spectra of the transients vary strongly with the polarity of the solvent used. First order decay rate constants are given in Table 4. 

P A659-R> 18th line 5, 51 - Dinitro-o-azostilbene instead of 5, 5 - Dinitro-o-stilbene Errata in Volume 2... 

Amm picrate, DATNB or DATB (1,3-Di-a mino-2,4,6-triaminobenzene) DIP AM (Dipicramid), EL-511 (Hexanitrodiphenyl Sulfone or Dipicryl Sulfone) HNDPhA or HNDPA j(Hexanitrodiphenylamine) Cyclo-tetraethylenetetranitramine HNOxn (Hexa-nitrooxanilide) HNS (or HNStb)(Hexanitro-stilbene) KDNBF (Potassium Dinitro-benzofuroxan) LA (Lead Azide) NGu (Nitroguanidine) NONA (Nona nitroter-... 

Dinitro-p-azostilbene or Azobis (3-nitro stilbene, called in Ref 2 3,3,-Dinitro-4/4 -distyryl-azobenzene, CjHg-CHiCH--QHsfNO NrN-QH NOJ-CHiCH-QH, carmine-red crysts mp 260-1°. Prepn and props are given in Ref 2... 

Dinitro-p-azostilbene or Azobis-(9-nitrostilbene, called in Beil Bis-[4 -nitro-stilbenyl-(4)]-diimid or [4 -Nitro-stilben]-<4azo4>-[4,-nitro- stilben], (OjN KAf- CH CH— C6H4-N N-C6H4-CH CH-CsH4(N01) yel-red Crystspmp 263°. It is listed in Beil 16, 84 without reference to its source was not found in CA through 1956... 

Dinitro-o-stilbene, called in Ref 2 5,5 -Dinitro-2,2 -distyryl-ozobenzene, C H --CH CH-QH3(N03>-N N-CeHj(N02) CH CH-QHs brick red crysts, decmpg ca 265° with melting. Prepn and props are given in Ref 2 Refs l)Beil — not found 2)L.Chardonnens P-Heinrich, Helv 23, 1414(1940) CA 35, 2122(1941)... 

Nitro-2-methylphenylarsinic sicid is transformed by sodium hypochlorite in alkaline solution to 5 5 -dinitro-2 2 -stilbene-l I -diarsinic acid, ... 

Interest is shown still in the isomerization of stilbene and its derivatives. A study of the pathways for the cis -trans isomerization of 4-nitro, 4,4-dinitro, and 4-nitro-4 -methoxy stilbenes has been reported. The dynamics of the photoisomerization of stilbenes in hydrocarbon solution has been studied and a comparison of the trans -cis isomerization of stilbene in low viscosity liquid alkanes and in the gas phase has been carried out. The photoisomerization of stilbene in straight chain alcohols has provided evidence for the existence of rotational relaxation in the excited and the ground states. An analysis of the isomerization rates of photoexcited stilbene has been made and the photobehaviour of poly deuteriated stilbene has been studied. ... 

Condensation ofNitro Compounds. The stflbene dyes derived from condensation of 4-nitrotoluene-2-sulfonic acid [121-03-9] (para acid) in aqueous caustic solution either alone or with aryl amines, are mixtures of dyes containing azo and azoxy groups with indefinite structures. The primary products are 4,4,-dinitro-2>2,-stilbenedisulfonic acid [128 42-7] and 4,4,dinitrodibenzyl-2>2,-disulfonic acid [6404-60-0] which condense further to form the dye. The properties of the stilbene dyes vary with the amounts and concentrations of the reactants and with the time and temperature of heating. The hue... 

Whitten and co-workers [230] have amply investigated stilbene isomerization induced by excited porphyrins. Electron-deficient nitrostilbenes quench excited Zn or Mg etioporphyrins through exciplex formation. Light absorbed by the porphyrin affects isomerization of 4-nitro- or 4,4 -dinitro-stilbene with low quantum yields ((%trans)sens = 99.5), possibly via a stilbene exchange chain mechanism [230]. Azastilbenes coordinate to me-talloporphyrins in both the ground and the excited state (but do not quench it), and isomerize efficiently upon selective excitation of the porphyrin [231]. Complexed 1,4 -NPE gives d , = 6.6, = 0.2, and (%trans)sens = 96,... 

Here, 3t is an upper excited triplet state with trans configuration which, depending on the further substitution and on external factors (e.g., solvent polarity) may be located above or below t. For 4-nitro- and 4,4 -dinitro-stilbene the energy of t is 335-375 kJ mol. For 4,4 -NMS (as well as for the more polar 4,4 -NDS) the energy of t is lowered by solvation. Because of the high dipole moment a large Stokes shift is observed in polar solvents. The energy of 3t (e.g., ET = 188 kJ mol"1 for 4,4 -NMS [400]) is probably... 

Ethenediyl)bis(5-nitrobenzenesulfonic acid), di-sodium salt. Benzenesulfonic acid, 2,2 -(1,2-ethenediyl)bis(5-nitro-, disodium salt 4,4 -Dinitrostilbene-2,2 -disulfonic acid, disodium salt Disodium 4,4 -dinilro-2,2 -stilbene-disulfonic acid Disodium 4,4 -dinitro-2,2 -stilbene-disulfonate Disodium 4,4 -dinitrostilbene-2,2 -disulphon-ate EINECS 223-051-2 NSC 163175 2,2 -Stilbenedisulfonic acid, 4,4 -dlnltro-, disodium salt. 

Denitration of yic-dinitro compounds. tranr-Stilbene (2) and 9,9 -bifluoi-enylidene (4) can be obtained by denitration of (1) and (3), respectively, with anhydrous stannous chloride or the dihydrate (4 eq.). This method fails in the case of aliphatic vic-dinitro compounds. ... 

The product of reaction of sodium hydroxide with p-nitrobenzyldimethyl-sulfonium tosylate in water at 60°C is a mixture of cis- and trani-4,4 -dinitro-stilbenes in 99% yield Again, the reaction is first order in each reactant. After a short reaction time in DO /DaO the benzylic protons were at least 97% exchanged for deuterium . This eliminates the carbanion displacement mechanism. The over-all sulfur isotope effect is 1.0066 0.0008, lower... 

Diethyl 2,2 -dinitro-( )-stilbene-4,4 -dicarboxylate 132 proved to be a convenient starting compound in the synthesis of diethyl benzo[Z)]thieno[3,2- >]benzo[fe]thio-phene-2,7-dicarboxylate (133) and its selenium analogue 134 (93JOC5209). 

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