Search results for "modification"
showing 10 items of 853 documents
Post-synthetic methods for functionalization of imidazole-fused porphyrins
2018
Several methods for the post-synthetic modification of imidazo[4,5-[Formula: see text]]porphyrins are reported. First, a synthetic approach to the isomeric difunctionalized porphyrins, containing two [Formula: see text]-fused 2-aryl-1[Formula: see text]-imidazole cycles at adjacent or opposite pyrrole rings of the macrocycle is developed. The core chemistry of this synthetic route is the transformation of 2-aryl-1[Formula: see text]-imidazo[4,5-[Formula: see text]]porphyrins into corresponding imidazodioxochlorins followed by Debus–Radziszewski condensation with aromatic aldehyde. Next, 2-(4-bromophenyl)-1[Formula: see text]-imidazo[4,5-[Formula: see text]]-5,10,15,20-tetramesitylporphyrin…
How do different surface modification strategies affect the properties of MnO nanoparticles for biomedical applications? Comparison of PEGylated and …
2011
ABSTRACTMnO nanoparticles (NPs) were surface functionalized by two different approaches, (1) using a dopamine-poly(ethylene glycol) (PEG) (DA-PEG) ligand and (2) by encapsulation within a thin silica shell applying a novel approach. Both MnO@DA-PEG and MnO@SiO2 NPs exhibited excellent long-term stability in physiological solutions. In addition, the cytotoxic potential of both materials was comparatively low. Furthermore, owing to the magnetic properties of MnO NPs, both MnO@DA-PEG and MnO@SiO2 lead to a shortening of the longitudinal relaxation time T1 in MRI. In comparison to the PEGylated MnO NPs, the presence of a thin silica shell led to a greater stability of the MnO core itself by pre…
1991
Synthesis of small carboranylsilane dendrons as scaffolds for multiple functionalizations.
2006
Small carbosilane dendrons in which a closo-carborane is located at the focal point have been prepared by a sequence of steps involving hydrosilylation and reduction reactions. These compounds are used as scaffolds for peripheral functionalization with styrene, chlorovinylstyrene, or suitable carboranes, while keeping the C(cluster)-Si (C(c)-Si) bond. Modification of the core by reduction of the carborane with Mg/BrCH2CH2Br was also achieved.
Concave Tetrathiafulvalene-Type Donors as Supramolecular Partners for Fullerenes
2007
The cap fits! A new class of concave π-extended tetrathiafulvalene (TTF) derivatives, truxene-TTFs, were prepared and characterized, and their self-assembly with fullerenes was investigated (see picture). Truxene-TTFs represent the first example of TTF-related electron donors that serve, without chemical modification, as monotopic receptors for fullerenes in solution. (Chemical Equation Presented). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.
From Single Molecules to Nanoscopically Structured Functional Materials
2006
AbstractThe synthesis of MS2 (M = Mo, W) onion-like nanoparticles by means of a high temperature MOCVD process starting from W(CO)6 and elemental sulfur is reported. The reaction can also be carried out in two steps where the intermediate amorphous WS2 nanoparticles formed through the high temperature reaction of tungsten and sulfur in the initial phase of the reaction are isolated and converted in a separate annealing step to onion-type WS2 nanoparticles. Based on a study of the temperature dependence of the reaction a set of conditions could be derived where onion-like structures were formed in a one-step reaction. Onion-like structures obtained in the single-step process were filled, whe…
Organic Field Effect Transistors: Noncovalent Functionalization and Passivation of Black Phosphorus with Optimized Perylene Diimides for Hybrid Field…
2020
Process Development for Wet-Chemical Surface Functionalization of Gallium Arsenide Based Nanowires
2019
ChemInform Abstract: Palladium-Polypyrrole Nanocomposites Pd@PPy for Direct C-H Functionalization of Pyrroles and Imidazoles with Bromoarenes.
2016
Palladium–polypyrrole nanocomposites (Pd@PPy) with unique combination of high palladium dispersion (nanoparticle size 2.4 nm) and high palladium content (35 wt%) are efficient catalysts for the selective arylation of substituted pyrroles and imidazoles with either activated or deactivated aryl bromides. The performances of the recoverable supported palladium catalyst matches the best performances of homogeneous systems based on Pd(OAc)2 at 0.5–0.2 mol%, and largely overwhelm the classical Pd/C catalyst.