1625-84-9

Usage

InChI:InChI=1/C20H10N4/c21-9-19(10-22)17-13-5-1-2-6-14(13)18(20(19,11-23)12-24)16-8-4-3-7-15(16)17/h1-8,17-18H

Upstream product

• 120-12-7 anthracene 
• 670-54-2 ethenetetracarbonitrile 
• 613-31-0 9,10-dihydroanthracene 
• 109828-65-1 C₃₂H₃₂Si 
• 94732-90-8 5,5,6,6-tetracyano-2-thiabicyclo<2.2.0>hexane 
• 13223-78-4 tetranitroethylene 
• 1627-06-1 5,6,11,12-tetrahydro-5,12;6,11-di-o-benzeno-dibenzo[a,e]cyclooctene 

Downstream Products

• 120-12-7 anthracene 
• 670-54-2 ethenetetracarbonitrile 

Relevant academic research and scientific papers

Synthesis of ferrocenyl derivatives of anthracene

1-Ferrocenylanthraquinone has been synthesised from the cheap and commercially available 1-diazoniumanthraquinone (Aldrich Fast Red Al salt).Reduction of this anthraquinone with aluminium alkoxide has given good yields of 1-ferrocenyl-anthracene, the first preparation of such polycyclic ferrocenes.The TCNE adduct of the anthracene was prepared in good yield, in marked contrast to the outcome of the redox reaction of ferrocene itself with TCNE.No oxidation was observed with TCNQ.Diels-Alder addition of benzyne resulted in a very low yield (ca. 1 percent)of 1-ferrocentyltriptycene.The 1H and 13C NMR spectra are reported, and discussed in detail together with 57Fe Moessbauer data.

ELECTRON TRANSFER ACTIVATION OF THE DIELS-ALDER REACTION QUANTITATIVE RELATIONSHIP TO CHARGE TRANSFER EXCITED STATES

The Diels-Alder cycloaddition of anthracene to tetracyanoethylene (TCNE) is quantitatively compared to alkylmetal insertion under the same reaction conditions.In both systems, the observation of transient charge transfer (CT) absorption bands is related to the presence of 1:1 electron donor-acceptor complexes of anthracene (Ar) and alkylmetal (RM) donors with the TCNE acceptor.The activation free energies ΔG(excit.) for anthracene cycloaddition and alkylmetal insertion are found to be equal to the energetics of ion-pair formation, i.e. and ,which are evaluated from the CT transition energies hνCT.Indeed,the differences in the rates of alkylmetal insertion and anthracene cycloaddition by a factor of more than 10E9, are shown quantitatively to arise from the differences in ion-pair solvation ΔGs.The same differences in ΔGs also apply quantitatively to the free ions, and , independently derived from the electrochemical and iron(III) oxidations of alkylmetals and aromatic compounds, respectively, by outer-sphere electron transfer.The charge transfer formulation of the activation process thus provides a unifying basis for comparing such diverse processes as Diels-Alder cycloadditions and organometal cleavages, when a common electron-deficient acceptor is employed.The relationship to the concerted mechanisms of the Diels-Alder reaction is discussed.

Diels-Alder reaction rate in the solid state and the evidence of the location of molecular complexes between the reagents on the reaction pathway

The rate of reactions in the solid phase with uniform grinding of crystals of dienes, anthracene, and 9,10-dimethylanthracene, with dienophiles, tetracyanoethylene, N-phenylmaleimide, and 4-phenyl-1,2,4-triazoline-3,5-dione, has been studied. It was shown

Reactivity Variation of Tetracyanoethylene and 4-Phenyl-1,2,4-Triazoline-3,5-Dione in Cycloaddition Reactions in Solutions

The reasons for the very high reactivity and variability of reactivity of two dienophiles, tetracyanoethylene (1) and 4-phenyl-1,2,4-triazoline-3,5-dione (2), in the Diels–Alder reactions were considered. The data on the rate of reactions with anthracene (3), benzanthracene (4) and dibenzanthracene (5) in 14 solvents over a range of temperatures and high pressures, data on the change in the enthalpy of solvation of reagents, transition state, and adducts in the forward and backward reactions, and the enthalpies of these reactions in solution were obtained. Strong π-acceptor dienophile 1 has sharply reduced reactivity in reactions in π-donor aromatic solvents. It was observed that the π-acceptor properties of dienophile 1 disappear upon passage to the transition state and adduct. Large solvent effects on the reaction rate can be predicted for all types of reactions involving tetracyanoethylene. Very high reactivity of dienophiles 1 and, especially, 2 can be useful to catch such carcinogenic impurities such as 3–5 and neutralize them by transformation into less dangerous adducts.

Theoretical and structural analysis of long C-C bonds in the adducts of polycyanoethylene and anthracene derivatives and their connection to the reversibility of diels-alder reactions

X-ray structure determinations on four Diels-Alder adducts derived from the reactions of cyano- and ester-substituted alkenes with anthracene and 9,10-dimethylanthracene have shown the bonds formed in the adduction to be particularly long. Their lengths range from 1.58 to 1.62 A, some of the longest known for Diels-Alder adducts. Formation of the four adducts is detectably reversible at ambient temperature and is associated with free energies of reaction ranging from -2.5 to -40.6 kJ mol-1. The solution equilibria have been experimentally characterised by NMR spectroscopy. Density-functional-theory calculations at the MPW1K/6-31+G(d,p) level with PCM solvation agree with experiment with average errors of 6 kJ mol-1 in free energies of reaction and structural agreement in adduct bond lengths of 0.013 A. To understand more fully the cause of the reversibility and its relationship to the long adduct bond lengths, natural-bond-orbital (NBO) analysis was applied to quantify donor-acceptor interactions within the molecules. Both electron donation into the σ-anti-bonding orbital of the adduct bond and electron withdrawal from the σ-bonding orbital are found to be responsible for this bond elongation. Copyright

The nature of lithium perchlorate and gallium chloride salt effect in cycloaddition reactions

Comparing the acceleration effects of (4 + 2)-, (3 + 2)- and (2 + 2)-cycloaddition reactions in the presence of the salts of two types: gallium chloride in inert solvents and lithium perchlorate (LP) in diethyl ether (DE) it was observed that in the presence of GaCl3 the acceleration effect is approximately the same (104 times) for the studied reactions, while in LPDE medium for the same reactions strong increase (up to 104 times), weak increase or even decrease of the rate and equilibrium constants take place even with the common dienophile depending on the nature of the second reagent. it was suggested that the acceleration effect of cycloaddition reactions in the presence of such Lewis acids as aluminum, gallium or boron halides is due to the sharp increase of Π-acceptor properties of dienophiles and therefore increasing energy of orbital interaction, whereas LPDE medium demonstrates strong stabilization of static and/or dynamic polar forms and favors reactions with charge control.

Charge-transfer complex formation and photo-induced electron-transfer reaction of dibenzo-7-silabicyclo[2.2.1]hepta-2,5-dienes

Dibenzo-7-silabicyclo[2.2.1]hepta-2,5-dienes (1a, 1b) are excellent electron donors because of effective σ-π conjugation between the orbitals of C-C π bonds and Si-C σ bonds. Some of their donor properties are demonstrated by the reactions with some electron accepters. When 1a and 1b are mixed with tetracyanoethylene, facile formation of charge-transfer complexes was observed. In the 2,4,6-triphenylpyrylium tetrafluoroborate-sensitized photoreaction of 1b, the corresponding difluorosilane and anthracene were obtained in good yields. The structural and electronic features of radical cation 1a+. were provided by semiempericaI molecular orbital calculation. In addition, the structure of 1a in crystals was determined by X-ray crystallography and compared with that obtained by the calculation.

Cycloreversion of Arene Endoperoxides induced by Electron Transfer

Cycloreversion of arene endoperoxides 1-4 can be induced by photoexcitation of their electron donor-acceptor complexes with tetracyanoethylene.

KINETIC AND THERMOCHEMICAL INVESTIGATION OF THE FORWARD AND REVERSE DIELS-ALDER REACTIONS OF TETRACYANOETHYLENE WITH ANTHRACENE AND 9,10-DIMETHYLANTHRACENE IN CERTAIN SOLVENTS

The Diels-Alder reaction of tetracyanoethylene with anthracene and 9,10-dimethylanthracene was studied in the forward and reverse directions in a series of solvents.The rate constants, enthalpies and entropies of activation, enthalpies of solution of the reagents and adducts, and enthalpies of the reaction were determined.The changes in the enthalpy of solvation of the reagents, the products, and the transition state for the forward and reverse processes were calculated from the obtained data.The equality of the enthalpies of the reaction obtained from the thermochemical (ΔHr) and kinetic (ΔH1-ΔH-1) measurements suggests that the energies of intermolecular stabilization in the transition state for the forward and reverse Diels-Alder reactions are equal.The indentical changes in the enthalpy of solvation of the transition state for the forward and reverse reactions are consistent with its equilibrium solvation.

Intermolecular perturbation approach to specific solvent effects

One possible specific solvent effect, namely, the ?-donor ability is considered in the light of simple intermolecular second order perturbation theory.By using the Polanyi-Evans-Bell principle this theory predicts that increasing ?-donor ability of solvent should decrease the reaction rate.This prediction is fully borne out by experimental data observed for the solvent effect on 4 + 2 cycloaddition of tetracyanoethylene to anthracene.