Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 8 of 8 for “"Ortho Positions"”.
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Early transition metal catalysts for the living polymerization of olefins and alkynes
… or fluorines (especially the latter) in the ortho positions was found to be detrimental to the development of living olefin polymerization catalysts of this general type. The catalytic activity steadily decreased in the order aryl = Mes > 2,6-Cl2C6H3 > 2,6-F2C6H3 and 1,2 and 2,1 -hydride …
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A study of the cyclodehydrohalogenation of 12-(2-chloro-5- methylphenyl)benz[a]anthracene
… might undergo ring closure at either of the ortho positions of the phenyl ring. These positions are not equivalent with respect to the methyl group and ring closure might yield either 2-methyl dibenzo[a,l]pyrene or 4-methyldibenzo[a,l]- pyrene or a mixture of both isomers. When the compound, …
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A study of the aromatic cyclodehydration of 2-(2-naphthylmethyl)- 2'-chloro-5'-methylbenzophenone
… might take place at either of the two ortho positions or the phenyl ring. These positions are not equivalent with respect to the methyl group and ring closure might yield either 2-methyldibenzo[a,1]pyrene or 4-methyldibenzo[a,1]pyrene or both. The objectives of the present investigation …
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Two approaches to the design and synthesis of bimetallic complexes
… for formamidines with bulky substituents in the ortho positions, indicating two major stereoisomers ( E and Z conformers) co-existing in solution. In solid state, strong stability for E conformers was gained from a pair of H bonds between two ligands facing each other. The phenomenon was observed …
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A structure-reactivity study of selected phosphorus compounds
… and the presence of bulky substituents at the ortho positions of the benzene ring prevents dimer formation. The X-ray crystal structure determination of the carboxylic analogues of the phosphoric amides above, (R)PhNHC(O)R' (R = p-OMe, p-NO₂ and R' = Me or Ph), serves to indicate the …
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Highly Efficient Catalysts for the Dimerization of α-Olefins
… Steric demanding substituents at the ortho positions of the iminophenyl ring had positive effects on the dimer yield. The influence of triphenylphosphine as an additive was investigated and strong dependencies could be observed. Addition of triphenylphosphine had no effect on the dimer …
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Mechanochemical Reaction Development for Addition, Elimination, and Isomerization
… coupling is explored at three regiochemical dispositions: ortho, meta and para. In contrast to the fact that all compounds can be activated thermally, cubane is mechanically activated only when coupled at ortho positions. Through mechanical activation, cubane reacts to form a thermally …