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— The anisotropic and active properties of the perfectly matched layer (PML) absorbers significantly deteriorate the finite-element method (FEM) system condition and as a result, convergence of the iterative solver is substantially affected. To address this issue, we examine the generalized minimal residual (GMRES) solver for solving finite-element systems(More)
—Patch antennas on ferrite substrates allow for pattern control, frequency shifting, and scattering reduction. This is achieved by external magnetic field biasing coupled with the inherent magnetization of the ferrite substrate. Measurements and analytical studies based on the method of moments (MoM) have verified these attractive properties of ferrite(More)
Most organic radicals possess short lifetimes and quickly undergo dimerization or oxidation. Here, we report on the synthesis by radical templation of a class of air- and water-stable organic radicals, trapped within a homo[2]catenane composed of two rigid and fixed cyclobis(paraquat-p-phenylene) rings. The highly energetic octacationic homo[2]catenane,(More)
Motor molecules present in nature convert energy inputs, such as a chemical fuel or incident photons of light, into directed motion and force biochemical systems away from thermal equilibrium. The ability not only to control relative movements of components in molecules but also to drive their components preferentially in one direction relative to each(More)
Polyaromatic compounds are well-known to intercalate DNA. Numerous anticancer chemotherapeutics have been developed upon the basis of this recognition motif. The compounds have been designed such that they interfere with the role of the topoisomerases, which control the topology of DNA during the cell-division cycle. Although many promising(More)
Three structures, based on γ-cyclodextrin (γ-CD) and metal ions (Cu(2+), Li(+), Na(+), and Rb(+)), have been prepared in aqueous and alkaline media and characterized structurally by single-crystal X-ray diffraction. Their dimeric assemblies adopt cylindrical channels along the c axes in the crystals. Coordinative and hydrogen bonding between the cylinders(More)
Gold recovery using environmentally benign chemistry is imperative from an environmental perspective. Here we report the spontaneous assembly of a one-dimensional supramolecular complex with an extended {[K(OH₂)₆][AuBr₄](α-cyclodextrin)₂}n chain superstructure formed during the rapid co-precipitation of α-cyclodextrin and KAuBr₄ in water. This phase change(More)
A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components-namely oligoviologens-in which different numbers of 4,4'-bipyridinium (BIPY(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT(4+)) rings following(More)
The organization of trisradical rotaxanes within the channels of a Zr6-based metal-organic framework (NU-1000) has been achieved postsynthetically by solvent-assisted ligand incorporation. Robust Zr(IV)-carboxylate bonds are forged between the Zr clusters of NU-1000 and carboxylic acid groups of rotaxane precursors (semirotaxanes) as part of this building(More)
Gold recovery using environmentally benign chemistry is imperative from an environmental perspective. Here we report the spontaneous assembly of a one-dimensional supramolecular complex with an extended {[K(OH 2) 6 ][AuBr 4 ] C(a-cyclodextrin) 2 } n chain superstructure formed during the rapid co-precipitation of a-cyclodextrin and KAuBr 4 in water. This(More)
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