42467-40-3Relevant articles and documents
Influence of Steric Effects on the Excited Triplet-State Lifetime of 2,2'-Dinitrostilbene and 2,2',4,4',6,6'-Hexanitrostilbene in Acetonitrile Solution
Smit, K. J.
, p. 6555 - 6558 (1992)
Solutions of 4,4'-dinitrostilbene, 2,2'-dinitrostilbene, 2,2',4,4',6,6'-hexanitrostilbene (HNS), and deuterated derivatives of HNS in acetonitrile have been studied by laser flash photolysis.Transient species with decay lifetimes of 125, 55, and 21 ns, respectively, were observed for the nondeuterated compounds.The decay lifetimes for these species provide evidence that the excited triplet-state lifetime is being reduced as steric hindrance to molecular planarity is increased.This is partly attributed to a reduction in the S0-T1 energy gap of the perpendicular configuration with increasing intramolecular steric hindrance although, for HNS, rapid formation of photoproducts also occurs.The degree of intramolecular steric hindrance associated with nitro groups ortho to the central double bond is indicated by singlet ground-state absorption measurements.
Synthesis of stilbene analogues by one-pot oxidation-Wittig and oxidation-Wittig-Heck reaction
Saiyed, Akeel S.,Patel, Krupa N.,Kamath, Bola V.,Bedekar, Ashutosh V.
supporting information; experimental part, p. 4692 - 4696 (2012/09/10)
Synthesis of symmetrical (and unsymmetrical) stilbene derivatives is achieved by a combination of one-pot steps of Kornblum type oxidation of benzyl halide, its simultaneous in situ formation of phosphonium salt, and subsequently their Wittig reaction. In other variant it is oxidized to aldehyde, treated with ylide generated from phosphonium salt (CH3PPh3X) to give styrene, and subjected to Pd catalyzed Heck reaction with arylhalide to give stilbenes as the three-step one-pot sequence.
trans-2,2′-dinitrostilbene as a precursor of 0-nitrobenzaldehyde, a key intermediate for pharmaceuticals: Reactivity and molecular structure studies
Sainz-Diaz, Claro I.,Hernandez-Laguna, Alfonso
, p. 1489 - 1495 (2007/10/03)
A novel synthesis of o-nitrobenzaldehyde by means of the ozonolysis-reductive hydrolysis of symmetrical trans-2,2′-dinitrostilbene is reported, yielding only the ortho isomer of nitrobenzaldehyde. This new route reduces environmental hazards in the synthesis of o-mtrobenzaldehyde. The central ethylene bond of trans-2,2′-dinitrostilbene showed a high reactivity for the ozonolysis reaction. The molecular structures of 2-nitrobenzaldehyde and trans-2,2′-dinitrostilbene were studied theoretically by means of ab initio quantum mechanical calculations at the 6-31G*//6-31G* level. A non-coplanar conformer was found for o-nitrobenzaldehyde, where the carbonyl and nitro groups are slightly twisted with respect to the phenyl ring. Also, a non-coplanar minimal s-trans-gauchels-transgauche conformer (NO2-aryl-C=C-aryl-NO2) was found for trans-2,2′-dinitrostilbene, where the aromatic groups are twisted with respect to the central double bond, and the nitro groups are also twisted out the planes of the aromatic rings. This structure is consistent with certain experimental physical-chemical properties of this molecule.
