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The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform
Curtis P Berlinguette – 1st expert on this subject based on the ideXlab platform
resolving orbital pathways for intermolecular electron transferNature Communications, 2018Co-Authors: Cameron W Kellett, Wesley B Swords, Michael D Turlington, Gerald J Meyer, Curtis P BerlinguetteAbstract:
Over 60 years have passed since Taube deduced an orbital-mediated electron transfer mechanism between distinct metal complexes. This concept of an orbital pathway has been thoroughly explored for donor–acceptor pairs bridged by covalently Bonded Chemical residues, but an analogous pathway has not yet been conclusively demonstrated for formally outer-sphere systems that lack an intervening bridge. In our present study, we experimentally resolve at an atomic level the orbital interactions necessary for electron transfer through an explicit intermolecular bond. This finding was achieved using a homologous series of surface-immobilized ruthenium catalysts that bear different terminal substituents poised for reaction with redox active species in solution. This arrangement enabled the discovery that intermolecular chalcogen⋯iodide interactions can mediate electron transfer only when these interactions bring the donor and acceptor orbitals into direct contact. This result offers the most direct observation to date of an intermolecular orbital pathway for electron transfer. It is known that intermolecular interactions impact electron transfer rates, but the mechanisms involved are challenging to define experimentally. Here, the authors have developed a platform that enables atomic orbital resolution of electron transfer through an explicit intermolecular interaction.
Xiaodong Li – 2nd expert on this subject based on the ideXlab platform
Effects of isomerization and concentration on the surface plasmon induced intermolecular hydrogen bonds enhancement of fluorobromobenzaldehydesChemical Physics Letters, 2019Co-Authors: Jia Li, Jiyu Wang, Meixia Zhang, Peng Song, Xiaodong LiAbstract:
Abstract The surface plasmon facilitated intermolecular hydrogen bonds enhancement of fluorobromobenzaldehyde (F-BB) isomers on Ag nanoparticles have been investigated by means of surface-enhanced Raman scattering (SERS). Comparing the SERS spectra and normal Raman scattering (NRS) spectra, the intensity of the O⋯H bending vibration peak was found to be clearly enhanced, and a new C O peak appeared in the SERS spectrum. The C O stretching vibration Raman spectrum reduced. We surmise that intermolecular hydrogen bonds are strengthened, due to the surface plasmon effect generated hot electrons act on the aldehyde group. Our work may promote further investigations on intra/intermolecular hydrogen-Bonded Chemical systems.
Changming Zhao – 3rd expert on this subject based on the ideXlab platform
Small-Angle X-ray Scattering Study of the Pulley Effect of Slide-Ring GelsMacromolecules, 2006Co-Authors: Yuya Shinohara, Y. Okumura, Changming Zhao, Kentaro Kayashima, † Kohzo Ito, Yoshiyuki AmemiyaAbstract:
The structure of slide-ring (SR) gels in various types of solvents was investigated by small-angle X-ray scattering (SAXS). The SR gels have a unique characteristic called the “pulley effect” that the cross-links made of α-cyclodextrin molecules in a figure-eight shape can slide along the polymer chain. The SAXS results show that, in a poor solvent, the sliding cross-links form aggregates that prevent the pulley effect, while the polymer chains freely pass through the cross-links acting like pulleys in a good solvent. A vertically elliptic pattern was observed in two-dimensional SAXS profiles for covalent-Bonded Chemical gels in a good solvent under uniaxial horizontal deformation, while an isotropic profile was observed for the SR gels in a good solvent even under deformation. This difference in the deformation mechanism between the SR gels and the Chemical gels supports the pulley effect of the SR gels.
SANS Studies on Deformation Mechanism of Slide-Ring GelMacromolecules, 2005Co-Authors: Takeshi Karino, Y. Okumura, Changming Zhao, Toshiyuki Kataoka, Mitsuhiro ShibayamaAbstract:
The deformation mechanism of “slide-ring” (SR) gels was investigated with small-angle neutron scattering (SANS). The SR gels were prepared by coupling α-cyclodextrin (CD) molecules on polyrotaxane chains consisting of poly(ethylene glycol) and CD. Because of a hollow structure of CD molecules, the cross-links made of CD molecules in a figure-of-eight shape can slide along the polymer chain. A normal butterfly pattern was observed for the first time in two-dimensional SANS isointensity profiles for the SR gels under uniaxial deformation, where the normal butterfly pattern means a prolate isointensity pattern in the direction perpendicular to the stretching direction. However, by either increasing the cross-link density or increasing the stretching ratio, the normal butterfly patterns changed to abnormal butterfly patterns as are commonly observed in conventional covalent-Bonded Chemical gels. The difference in the deformation mechanism as well as the cross-linking inhomogeneities between the SR gels and th…