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Showing 1 to 8 of 8 for “"helicene"”.
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Multiple Kinetic Resolution of Tetrathia[7]helicenes. Towards the Study of Two Photon Circular Dichroism.
… its aim the asymmetric synthesis of tetrathia[7]helicene derivatives using a newly developed multiple kinetic resolution (multi-KR) approach. The derivatives obtained (formyl- and diformylhelicene) should also be useful intermediates for the synthesis of chiral push-pull systems. The first part …
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BORAHETEROHELICENES: SYNTHETIC METHODOLOGIES AND PROPERTIES OF A NOVEL CLASS OF BORON Π-CONJUGATED SYSTEMS
… can be achieved in helical-shaped PAHs, namely helicenes[2] which are screw-shaped inherently chiral polycycles, formed by ortho-fused aromatic or heteroaromatic rings. The presence of a helical structure in B-PAHs is expected to strongly influence their physico-chemical properties leading to …
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Crystal Structures of Helical Columnar pi-Conjugated Systems and Biodegradable Polyester
… helical columnar pi-conjugated systems, namely helicene-bisquinone and dendronized perylene bisimide derivative as well as of a biodegradable aliphatic polyester, namely poly-9-hydroxynonanoate, have been resolved by means of fibre X-ray diffraction. Enantiopure and racemic helicene-bisquinones …
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Synthesis of contorted nanographenes via multi-fold alkyne benzannulation reactions
… highly functionalized, laterally π-expanded, [5]helicene-like naphtho[1,2-a]pyrene derivatives in moderate to very good yields. We were able to utilize this method to expand conju-gation of the HBC core to get a variety of π-extended HBC NGs. The Suzuki cross-coupling of the halogen(s) …
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Helical Pitch, Hydrophobic Binding, Chiral Templation, and Supramolecular Chelation of M-Phenylene Ethynylene Foldamers
… of less soluble oligomers. A mPE oligomer with a helicene moiety in the backbone was designed and synthesized to template the helical handedness of the folded conformation. The conformation of this oligomer was examined by circular dichroism spectroscopy and observed to be highly dependent on …
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Higher kekulenes and Polymeric Helicenes
… synthesize, isolate and characterize polymeric helicenes. Because helicenes might have potential applications in the synthesis of ligands for asymmetric catalysis, molecular actuators, conductive and chiroptical materials, we are interested in developing them in polymeric form. Ring closing …
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Structure-Property Relationship of the Two-Photon Circular Dichroism of Compounds with Axial and Helical Chirality
… the effect of the nature of ICT on two hexahelicene derivatives. Our investigation demonstrated that the TPCD signal of chiral molecules with strong ICT does not only depend on the strength of this effect but on its nature, i.e. extension of the π–electronic delocalization increasing beyond …
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Part I. Rhodium-catalyzed asymmetric functionalization of allylic amines Part II. Harnessing kinetic driving forces in alkyne metathesis for the synthesis of complex molecular architectures
… but rather localized aromaticity in the helicene subunits. This work will facilitate future syntheses of Möbius macrocycles for structure-aromaticity studies and other applications.