94111-20-3

Upstream product

• 94111-22-5 <2-(2,4,6-Cycloheptatrien-1-yliden)-1-(4-nitrophenyl)ethyliden>propandinitril 
• 1514925-11-1 2-[2-(cyclohepta-2,4,6-trienyl)-1-(4-nitrophenyl)ethylidene]malononitrile 
• 26088-96-0 2-[1-(4-nitrophenyl)ethylidene]malononitrile 
• 100-19-6 (4-nitrophenyl)ethanone 
• 94111-24-7 3-Methoxy-2-(4-nitro-phenyl)-3,8a-dihydro-2H-azulene-1,1-dicarbonitrile 

Downstream Products

• 94111-22-5 <2-(2,4,6-Cycloheptatrien-1-yliden)-1-(4-nitrophenyl)ethyliden>propandinitril 
• 1448895-32-6 7-phenyl-2-(4-nitrophenyl)-1,8a-dihydroazulene-1,1-dicarbonitrile 
• 1448895-44-0 7-(4-nitrophenyl)-2-(4-nitrophenyl)-1,8a-dihydroazulene-1,1-dicarbonitrile 
• 1448895-30-4 7-(4-methoxyphenyl)-2-(4-nitrophenyl)-1,8a-dihydroazulene-1,1-dicarbonitrile 
• 1448895-24-6 7-bromo-2-(4-nitrophenyl)-1,8a-dihydroazulene-1,1-dicarbonitrile 
• 102780-28-9 <1-(4-Aminophenyl)-2-(2,4,6-cycloheptatrien-1-yliden)ethyliden>propandinitril 
• 102780-27-8 2-(4-aminophenyl)-1,8a-dihydroazulene-1,1-dicarbonitrile 

Relevant academic research and scientific papers

Syntheses of donor-acceptor-functionalized dihydroazulenes

The dihydroazulene (DHA)/vinylheptafulvene (VHF) photo/thermoswitch has been of interest for use in molecular electronics and advanced materials. The switching between the two isomers has previously been found to depend strongly on the presence of donor a

Dihydroazulene/Vinylheptafulvene Photochromism: Effects of Substituents, Solvent, and Temperature in the Photorearrangement of Dihydroazulenes to Vinylheptafulvenes

1,1-Dicyano-2-phenyl-1,8a-dihydroazulene (H-D) and a series of p-phenyl-substituted derivatives (R-D, R: NO2, CN, Br, Cl, CH3, OCH3, and NH2) were investigated by time-resolved and steady-state photochemical methods.The dihydroazulenes (DHAs) undergo an efficient photoreaction to the corresponding vinylheptafulvenes (VHFs), the quantum yield (ΦD->V) at room temperature ranges from 0.1 to 0.6.The VHFs (λV = 440-470 nm) are nonemitting and photochemically nonreactive and undergo a thermal rearrangement.The activation energy for this back-reaction is 18-21 kcal/mol.The A factor is in the (0.01-5) * 1010 s-1 range; it varies with substituent and increases with increasing solvent polarity.The photoproduct is formed via a singlet pathway, 1DHA* -> VHF; triplet states are not involved in this reaction.Fluorescence from the DHAs was observed, weakly in fluid solution and most efficiently in glasses at low temperatures (e.g., λf ca. 480 nm for the parent compound).The quantum yield (Φf) at -196 deg C ranges from 0.15 to 0.9.A transient (λmax ca. 450 nm, τT D->V is strongly retarded, the triplet is observable on direct excitation with a lifetime of less than 10 μs even at -196 deg C.The increase of Φf and the reverse effect for ΦD->V with decreasing temperature indicates competition of these processes due to an activation barrier (1DHA* -> VHF pathway.Characteristic features of the ground-state and first excited singlet energy surfaces are presented.

Substituent Dependency of the Dihydroazulene Vinylheptafulvene Photochromism: Steric and Electronic Effects of 9-Anthryl Compounds - New Access to Condensed Hydropentalenes

The synthesis of 2-(9-anthryl)-1,8a-dihydro-1,1-azulenedicarbonitrile (1a) from 8-methoxyheptafulvene (3) by cycloaddition (via tetrahydroazulene 5a) and elimination of methanol is described.On irradiation with visible light 1a is transformed into the vinylheptafulvene 2a, which is reconverted into 1a under thermal conditions.The steric congestion caused by the 9-anthryl substituent determines the rate of the cycloaddition as well as the kinetics of the thermal back reaction 2a -> 1a and causes thermochromic behavior of dihydroazulene 1a.By intramolecular electrophilic substitution tetrahydroazulene 5a yields the condensed hydropentalene 9 which on oxidation leads to the condensed polycycle 11.The stereochemical assignments of the 9-anthryl compounds were achieved mainly by one- and twodimensional 1H-NMR spectroscopy. - Key Words: Aromatics, condensed / Cycloaddition / Azulenes, tetrahydro- / Photochromism / Thermochromism

Light-Induced and Reversible Transformations: Syntheses and Properties of Photochromic 1,1-Dicyano-1,8a-dihydroazulenes and Thermochromic 8-(2,2-Dicyanovinyl)heptafulvenes

1,1-Dicyano-2-aryl-1,8a-dihydroazulenes 6(a-g) are prepared in a two-step synthesis starting from 8-methoxyheptafulvene and benzylidenemalononitriles via the tetrahydroazulenes 5.The compounds 6(a-h) rearrange to 8-(2,2-dicyano-1-arylvinyl)heptafulvenes 7(a-h) by irradiation with visible light.The back reaction of 7 to 6 occurs under thermal conditions.Donor-substituted compounds indicate higher long term stability of the equilibrium 6 7 (6f 7f > 44 h).Spectroscopic data of 6 and 7 are given.The molecular structures of the p-bromophenyl derivative 6c and of the p-methoxyphenyl derivative 7f are revealed through crystallography.Some results for the rearrangements 6 7 in the solid state are given.