1075-62-3Relevant articles and documents
Dictating Nanoparticle Assembly via Systems-Level Control of Molecular Multivalency
Santos, Peter J.,Cao, Zhen,Zhang, Jianyuan,Alexander-Katz, Alfredo,Macfarlane, Robert J.
, p. 14624 - 14632 (2019)
Nanoparticle assembly can be controlled by multivalent binding interactions between surface ligands, indicating that more precise control over these interactions is important to design complex nanoscale architectures. It has been well-established in natural materials that the arrangement of different molecular species in three dimensions can affect the ability of individual supramolecular units to coordinate their binding, thereby regulating the strength and specificity of their collective molecular interactions. However, in artificial systems, limited examples exist that quantitatively demonstrate how changes in nanoscale geometry can be used to rationally modulate the thermodynamics of individual molecular binding interactions. As a result, the use of nanoscale design features to regulate molecular bonding remains an underutilized design handle to control nanomaterials synthesis. Here we demonstrate a polymer-coated nanoparticle material where supramolecular bonding and nanoscale structure are used in conjunction to dictate the thermodynamics of their multivalent interactions, resulting in emergent bundling of supramolecular binding groups that would not be expected on the basis of the molecular structures alone. Additionally, we show that these emergent phenomena can controllably alter the superlattice symmetry by using the mesoscale particle arrangement to alter the thermodynamics of the supramolecular bonding behavior. The ability to rationally program molecular multivalency via a systems-level approach therefore provides a major step forward in the assembly of complex artificial structures, with implications for future designs of both nanoparticle- and supramolecular-based materials.
Reinforcing Supramolecular Bonding with Magnetic Dipole Interactions to Assemble Dynamic Nanoparticle Superlattices
Santos, Peter J.,Macfarlane, Robert J.
, p. 1170 - 1174 (2020)
Assembling superparamagnetic particles into ordered lattices is an attractive means of generating new magnetically responsive materials, and is commonly achieved by tailoring interparticle interactions as a function of the ligand coating. However, the inherent linkage between the collective magnetic behavior of particle arrays and the assembly processes used to generate them complicates efforts to understand and control material synthesis. Here, we use a synergistic combination of a chemical force (hydrogen bonding) and magnetic dipole coupling to assemble polymer-brush coated superparamagnetic iron oxide nanoparticles, where the relative strengths of these interactions can be tuned to reinforce one another and stabilize the resulting superlattice phases. We find that we can precisely control both the dipole-dipole coupling between nanoparticles and the strength of the ligand-ligand interactions by modifying the interparticle spacing through changes to the polymer spacer between the hydrogen bonding groups and the nanoparticles' surface. This results in modulation of the materials' blocking temperature, as well as the stabilization of a unique superlattice phase that only exists when magnetic coupling between particles is present. Using magnetic interactions to affect nanoparticle assembly in conjunction with ligand-mediated interparticle interactions expands the potential for synthesizing predictable and controllable nanoparticle-based magnetic composites.
METALLO-BETA-LACTAMASE INHIBITORS
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Page/Page column 66, (2017/04/04)
The present invention relates to compounds of formula I that are metallo-β-lactamase inhibitors, the synthesis of such compounds, and the use of such compounds for use with β-lactam antibiotics for overcoming resistance.
