Search results for "Metals"
showing 10 items of 2013 documents
Mixed silane self assembled monolayers and their in situ modification
1998
Mixed self assembled silane monolayers were prepared by coadsorption of Br and methyl terminated trichlorosilanes. By subsequent in situ modification the Br groups were converted into amino groups which can be used to tether polyglutamates to the surface. Here we describe the characterization of the monolayers by means of contact angle measurements and X-ray photoelectron spectroscopy (XPS). Both methods clearly indicate that the Br terminated silane is preferentially adsorbed from the solution. Following the in situ modification by XPS a yield of approximately 80% was determined for the substitution of the bromine by azide, whereas the yield for subsequent reduction to the amine is close t…
Crystal and molecular structure, and electronic properties of hexakis(imidazole)copper(II) formate
1996
The crystal and molecular structure of [Cu(Im)6] (HCOO)2 (Im = imidazole) has been determined by X-ray diffraction methods. The compound is built of centrosymmetric Cu(Im) inf6 sup2− cations and non-coordinated HCO2 − anions, linked through H-bonds giving a layered structure in the ac plane. The coordination polyhedron around the Cu atoms can be described as a rhombically-distorted octahedron (CuN2N′2N′'2 chromophores). Both electronic and e.p.r. spectra are indicative of an essentially d x2− y2 ground state for the CuII ions. No exchange coupling has been detected down to 4.2 K by means of magnetic susceptibility measurements. This feature is discussed on the basis of the structural data.
Template-controlled synthesis of chiral cyclohexylhemicucurbit[8]uril
2015
Enantiomerically pure cyclohexylhemicucurbit[8]uril (cycHC[8]), possessing a barrel-shaped cavity, has been prepared in high yield on a gram scale from either (R,R,N,N')-cyclohex-1,2-diylurea and formaldehyde or cycHC[6]. In either case, a dynamic covalent library is first generated from which the desired cycHC can be amplified using a suitable anion template.
Synthesis of huge macrocycles using two calix[4]arenes as templates.
2005
Macrocycles with up to 100 atoms have been synthesised using two calix[4]arenes as templates: first, (3,5-dialkenyloxy)phenyl groups are attached to the wide rim of a calix[4]arene via urea links, then the alkenyl groups are connected via a metathesis reaction using a tetratosylurea calix[4]arene for their correct prearrangement and finally the urea functions are cleaved to detach the newly formed macrocycles.
Gold(ii) in redox-switchable gold(i) catalysis
2019
Chemical communications 55(32), 4615 - 4618 (2019). doi:10.1039/C9CC00283A
A post-synthetic approach triggers selective and reversible sulphur dioxide adsorption on a metal-organic framework.
2018
We report the application of a post-synthetic solid-state cation-exchange process to afford a novel 3D MOF with hydrated barium cations hosted at pores able to trigger selective and reversible SO2 adsorption. Computational modelling supports the full reversibility of the adsorption process on the basis of weak supramolecular interactions between SO2 and coordinated water molecules.
Singlet and triplet energy transfer rate acceleration by additions of clusters in supramolecular pigment-organometallic cluster assemblies
2011
Both S(1) and T(1) energy transfer rates (porphyrin → cluster) increase from mono- to di- to tetracarboxylate[tetraphenyl-(zinc)porphyrin] adducts with [Pd(3)(dppm)(3)(CO)](2+) clusters.
Blue-emitting pyrene-based aggregates.
2015
The self-assembling features and gel formation of two pyrene imidazoles are presented. The supramolecular aggregation of these synthesised molecules results in an unusual blue-monomeric emission, which is rationalized by a combined experimental and theoretical investigation.
Unexpected photochemistry and charge-transfer complexes of [CB(11)H(12)](-) carborane.
2008
Although the [CB(11)H(12)](-) carborane does not exhibit an absorption band in UV, its triplet excited state can be generated upon 308 nm laser excitation; also unexpectedly carborane acts as electron donor forming a charge transfer complex with methylviologen that upon illumination gives rise to viologen radical cation.
Multielectron transfer in a dicopper(II) anthraquinophane.
2013
The new dinuclear copper(II) metallacyclophane with the non-innocent N,N'-1,4-bis(oxamate)-9,10-anthraquinone bridging ligand possesses a dual multielectron redox behavior featuring stepwise one-electron oxidation of the antiferromagnetically coupled Cu(II) ions and two-electron reduction of the anthraquinone spacers in a π-stacked anti conformation.