- METHOD FOR PRODUCING ALICYCLIC TETRACARBOXYLIC DIANHYDRIDE
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The present invention relates to a method for producing an acid dianhydride in which at least one of the following two operations (A) and (B) is performed when reacting an olefin compound with carbon monoxide. (A) After mixing a palladium compound, a copper compound and an alcohol compound in a reaction vessel, the substitution operation (C-2) described below and the stirring operation (C-1) described below are performed in that order, and the resulting product is mixed with the olefin compound. (B) After mixing a palladium compound, a copper compound, an alcohol compound and an orthoester compound in a reaction vessel, the substitution operation (C-2) described below is performed, and the resulting product is mixed with the olefin compound. (C-1) Stirring is performed under a carbon monoxide atmosphere. (C-2) After reducing the pressure inside the reaction vessel, an operation of introducingcarbon monoxide gas is performed at least once.
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Paragraph 0245-0247
(2019/11/23)
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- Solvent-mediated intramolecular electron transfer in U-shaped systems with different 'bite sizes'
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The rate of photoinduced charge separation is measured as a function of solvent for four donor (D)-bridge-acceptor (A) systems: DMN[10]DCV, DMN[10nb]DCV, DMN[10cy]DCV, and DMAN[10cy]DCV. In the first three members of this series, the D/A pair is kept constant and contains the strong dimethoxynaphthalene (DMN) donor which enables detection of electron transfer over a wide range of solvent polarity. In the fourth member, DMN is substituted by a dimethoxyanthracene (DMAN) unit, which decreases the driving force for photoinduced charge separation by about 0.58 eV and thereby limits the occurrence of electron transfer to polar solvents. In all systems the bridge is held at a length of 10 σ bonds. The configuration of the bridge is, however, varied to increase its bending in the series, which leads to center-to-center D/A distances decreasing from 13.4 A in the first system to 9.54 A in the second, and 7.50 A in the latter two. In DMN[10nb]DCV, the rate of intramolecular charge separation over 9.54 A is always smaller than that over 13.4 A in DMN[10]DCV, which is in line with a dominant through- bond mechanism that is more efficient via an extended array of σ bonds. However, in DMN[10cy]DCV, the rate is as high as or even higher than that in DMN[10]DCV. Although changes in the driving force are also important, as shown, for example, by the dramatic rate decrease in DMAN[10cy]DCV as compared to that of DMN[10cy]DCV, the high rates observed for DMN[10cy]DCV in polar aromatic solvent as well as in acetonitrile strongly indicate an important contribution of through-solvent interaction across the 7.5 A D/A distance, which in principle allows the intercalation of a single solvent molecule in close contact with both D and A. At the longer distance of 9.54 A in DMN[10nb]DCV, a smaller contribution of through-solvent interaction can still be detected for polar aromatic solvents but not for acetonitrile. The inherently discontinuous distance dependence of through-solvent interaction and its possible interesting dependence on molecular structure and temperature are discussed.
- Lokan, Nigel R.,Paddon-Row, Michael N.,Koeberg, Mattijs,Verhoeven, Jan W.
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p. 5075 - 5081
(2007/10/03)
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- Crystal Structures and Photoelectron Spectra of Some Trimethanoanthracenes, Tetramethanonaphthacenes, and Pentamethanopentacenes. Experimental Evidence for Laticyclic Hyperconjugation
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Photoelectron (p.e.) spectra of the series of dienes (4), (10), (11a)-(13a), and crystal structures for the dodecachlorodienes (11b)-(13b) are reported.The spectra revealed large ?-splitting energies of 0.32 and 0.52 eV for (4) and (11a) respectively.The value of (4) is attributed to the presence of orbital interactions through six ? bonds (OIT-6-B), and this, taken with the p.e. data for the dienes (1)-(3), provides convincing evidence for the long-range nature of OIT-n-B.The larger ?-splitting energy of 0.52 eV observed for (11a), compared with (4), has been explained in terms of the presence of two reinforcing orbital interactions: OIT-6-B and a new variant of hyperconjugation, called laticyclic hyperconjugation, in which the ? MOs of the double bonds mix the (Ψ)? MO of the central CH2 bridge of (11a).The surprisingly large ?-splitting energy of 0.29 eV observed for (12a) is also due largely to laticyclic hyperconjugation involving both pairs of symmetry adapted(Ψ)? MOs of the CH2 bridges.No ?-splitting energy could be detected in the p.e. spectrum of (13a).From the crystal structures of (11b)-(13b), it was found that the distance between neighbouring CH2 groups, and between a double bond and its closest CH2 neighbour is about 3 Angstroem in all three compounds.HF/STO-3G calculations on model ethene...(CH4)n...ethene complexes suggest that laticyclic interactions, like OIT-n-B, are very long-range processes, the predicted ?-splitting energies amounting to ca. 10-3 eV for two double bonds separated by ca. 33 Angstroem.The relevance of these orbital interactions to biological electron-transfer processes is briefly discussed.
- Paddon-Row, Michael N.,Englehardt, Lutz M.,Skelton, Brian W.,White, Allan H.,Joergensen, Flemming S.,Patney, Harish K.
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p. 1835 - 1850
(2007/10/02)
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- THE SYNTHESIS OF RIGID NORBORNYLOGS FOR THE PURPOSE OF STUDYING ORBITAL INTERACTIONS THROUGH BONDS
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The synthesis of members of the series of rigid bichromophoric norbornylogs 4-8 is described.Dienes 4a and b were synthesized according to Scheme 1.Reductive dechlorination of 26-28 (Scheme 2) gave dienes 5b-d, respectively.Benzene annelation of the appropriate ene substrate, using tetrachlorodimethoxycyclopentadiene, as outlined in Scheme 3, gave the dibenzo compounds 6a-c.The dibromoquinodimethane intermediate 49 was trapped by the appropriate diene to give the bisnaphtho compounds 7a-c.The extended norbornylogs 8a and b were synthesized using a combination of metal catalyzed (2+2) cycloaddition of DMAD and (2+2+2) cycloaddition of quadricyclane to ene substrates (Scheme 5).The photoelectron spectra of some of the dienes are discussed in terms of through bond orbital interactions.
- Paddon-Row, Michael N.,Cotsaris, Evangelo,Patney, Harish K.
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p. 1779 - 1788
(2007/10/02)
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