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Full-Text Articles in Physical Sciences and Mathematics
Proximal Effects In Bimetallic Catalysts For Olefin Polymerization, In Cross Metathesis Of Poly(3-R-Cyclooctenes), And In Multiblock Polymers, Madalyn Radlauer, Theodor Agapie, Marc Hillmyer
Proximal Effects In Bimetallic Catalysts For Olefin Polymerization, In Cross Metathesis Of Poly(3-R-Cyclooctenes), And In Multiblock Polymers, Madalyn Radlauer, Theodor Agapie, Marc Hillmyer
Faculty Publications, Chemistry
Proximity and sterics play a large role in polymerization and polymer chemistry. In the development and testing of bimetallic polymerization catalysts where the two metal centers are held on the same side of the molecule by a rigid ligand framework, the proximity of the second metal changes reactivity at the first. The resulting enhancements of polar group tolerance or isoselecitivity in olefin polymerization are not observed in related bimetallic systems with distal metal centers or in monometallic analogues. In cross metathesis between poly(cyclooctene) chains, high E-stereoregularity and head-to-tail regioregularity are achieved with Grubbs second or third generation catalysts when there …
Conformational Changes And Chiroptical Switching Of Enantiopure Bis-Helicenic Terpyridine Upon Zn2+ Binding, Helena Isla, Monika Srebro-Hooper, Marion Jean, Nicolas Vanthuyne, Thierry Roisnel, Jamie Lunkley, Gilles Muller, J. Gareth-Williams, Jochen Autschbach, Jeanne Crassous
Conformational Changes And Chiroptical Switching Of Enantiopure Bis-Helicenic Terpyridine Upon Zn2+ Binding, Helena Isla, Monika Srebro-Hooper, Marion Jean, Nicolas Vanthuyne, Thierry Roisnel, Jamie Lunkley, Gilles Muller, J. Gareth-Williams, Jochen Autschbach, Jeanne Crassous
Faculty Publications, Chemistry
The molecular conformation of a bis-helicenic terpyridine system is strongly modified upon binding to Zn(II) ion, a process that is accompanied by large changes in the optical and chiroptical properties. This system affords a new type of helicene-based chiroptical switching.
Functionalized Cationic [4]Helicenes With Unique Tuning Of Absorption, Fluorescence And Chiroptical Properties Up To The Far-Red Range, I. Hernández Delgado, S. Pascal, A. Wallabregue, R. Duwald, C. Besnard, L. Guénée, C. Nançoz, E. Vauthey, R. Tovar, J. Lunkley, Gilles Muller, J. Lacour
Functionalized Cationic [4]Helicenes With Unique Tuning Of Absorption, Fluorescence And Chiroptical Properties Up To The Far-Red Range, I. Hernández Delgado, S. Pascal, A. Wallabregue, R. Duwald, C. Besnard, L. Guénée, C. Nançoz, E. Vauthey, R. Tovar, J. Lunkley, Gilles Muller, J. Lacour
Faculty Publications, Chemistry
Unprecedented regioselective post-functionalization of racemic and enantiopure cationic diaza [4]helicenes is afforded. The peripheral auxochrome substituents allow a general tuning of the electrochemical, photophysical and chiroptical properties of the helical dyes (26 examples). For instance, electronic absorption and circular dichroism are modulated from the orange to near-infrared spectral range (575–750 nm), fluorescence quantum efficiency is enhanced up to 0.55 (631 nm) and circularly polarized luminescence is recorded in the red (|glum| ∼ 10−3).