Using per(3,6-anhydro)cyclodextrin derivatives [per(3,6-anhydro)CD], it was possible to produce new lanthanide chelates by careful choice of the size and functional groups. Heptakis(3,6-anhydro-2-O-methyl)cyclomaltoheptaose fulfils the best criteria for complexation of lanthanide ions. Nuclear magnetic resonance was used to derive the association constants and the stoichiometries of these new complexes. Finally, a three-dimensional structure of these complexes consistent with the NMR data is proposed, to ascertain the position of lanthanide in the cavity of the per(3,6-anhydro)CD. For the present purposes, heptakis(2-O-acetyl-3,6-anhydro)cyclomaltoheptaose, octakis(2-O-acetyl-3,6-anhydro)cyclomaltooctaose, heptakis(3,6-anhydro-2-O-methyl)cyclomaltoheptaose and octakis(3,6-anhydro-2-O-methyl)cyclomaltooctaose have been synthesized and purified.
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http://dx.doi.org/10.1016/j.carres.2004.10.011 | DOI Listing |
Phys Rev Lett
December 2024
Joint Center for Quantum Information and Computer Science, NIST and University of Maryland, College Park, Maryland 20742, USA.
A key objective in nuclear and high-energy physics is to describe nonequilibrium dynamics of matter, e.g., in the early Universe and in particle colliders, starting from the standard model of particle physics.
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December 2024
Institut für Theoretische Physik, Hardenbergstraße 36, Technische Universität Berlin, D-10623 Berlin, Germany.
Heterogeneity is ubiquitous in biological and synthetic active matter systems that are inherently out of equilibrium. Typically, such active mixtures involve not only conservative interactions between the constituents but also nonreciprocal couplings, whose full consequences for the collective behavior still remain elusive. Here, we study a minimal active nonreciprocal mixture with both symmetric isotropic and nonreciprocal polar interactions.
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December 2024
Cornell University, Ithaca, New York 14853, USA.
Developing high-precision models of the nuclear force and propagating the associated uncertainties in quantum many-body calculations of nuclei and nuclear matter remain key challenges for ab initio nuclear theory. In this Letter, we demonstrate that generative machine learning models can construct novel instances of the nucleon-nucleon interaction when trained on existing potentials from the literature. In particular, we train the generative model on nucleon-nucleon potentials derived at second and third order in chiral effective field theory and at three different choices of the resolution scale.
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December 2024
Initiative for the Theoretical Sciences and CUNY-Princeton Center for the Physics of Biological Function, The Graduate Center, CUNY, New York, New York 10016, USA.
The random-energy model (REM), a solvable spin-glass model, has impacted an incredibly diverse set of problems, from protein folding to combinatorial optimization, to many-body localization. Here, we explore a new connection to secret sharing. We derive an analytic expression for the mutual information between any two disjoint thermodynamic subsystems of the REM.
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December 2024
Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan.
We investigate the scaling behavior of Nambu-Goldstone modes in the ordered phase of the Vicsek model, introducing a phenomenological equation of motion incorporating a previously overlooked nonlinear term. This term arises from the interaction between velocity fields and density fluctuations, leading to new scaling behaviors. We derive exact scaling exponents in two dimensions, which reproduce the isotropic scaling behavior reported in a prior numerical simulation.
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