Search results for "FULLERENE"
showing 10 items of 197 documents
ChemInform Abstract: Large Scale MOCVD Synthesis of Hollow ReS2Nanoparticles with Nested Fullerene-Like Structure.
2008
Topological effects of a rigid chiral spacer on the electronic interactions in donor-acceptor ensembles
2005
Two triads (donor-spacer-acceptor), etTTF-BN-C 6 0 (6) and ZnP-BN-C 6 0 (7), in which electron donors (i.e., exTTF or ZnP) are covalently linked to C 6 0 through a chiral binaphthyl bridge (BN), have been prepared in a multistep synthetic procedure starting from a highly soluble enantiomerically pure binaphthyl building block (1). Unlike other oligomeric bridges, with hinaphthyl bridges, the conjugation between the donor and the acceptor units is broken and geometric conformational changes are facilitated. Consequently, distances and electronic interactions between the donor and C 6 0 are drastically changed. Both donor-spacer-acceptor (D-s-A) systems (i.e., 6 and 7) exhibit redox processes…
Self-Assembly-Directed Organization of a Fullerene–Bisporphyrin into Supramolecular Giant Donut Structures for Excited-State Charge Stabilization
2021
Functional materials composed of spontaneously self-assembled electron donor and acceptor entities capable of generating long-lived charge-separated states upon photoillumination are in great demand as they are key in building the next generation of light energy harvesting devices. However, creating such well-defined architectures is challenging due to the intricate molecular design, multistep synthesis, and issues associated in demonstrating long-lived electron transfer. In this study, we have accomplished these tasks and report the synthesis of a new fullerene–bis-Zn-porphyrin e-bisadduct by tether-directed functionalization of C60 via a multistep synthetic protocol. Supramolecular oligom…
Theoretical prediction of the electronic properties of silicon fullerenes
1994
Summary form only given. High symmetry silicon clusters present currently intense interest because of the possibility they present properties similar to those displayed by fullerenes. Thermodynamic studies have shown that the buckminsterfullerene structure of Si6o is much more stable than other suggested structures. We present here a detailed investigation of the structure and electronic properties of silicon cluster analogous to fullerenes. We have made use of AMI method to obtain reliable geometrical parameters. The calculated valence effective Hamiltonian (VEH) electronic structures are used to predict ionization potentials, electron affinities, HOMO-LUMO energy gaps and first allowed tr…
A screening study on the fate of fullerenes (nC60) and their toxic implications in natural freshwaters
2013
Increasing usage of fullerenes (C60) increases their opportunities to be released into the environment. For risk assessment, it is important to understand the environmental fate and ecotoxicological effects of C60. In the present study, fullerene settling was measured during a 1-yr period with 4 different lake waters and an artificial freshwater, and Daphnia magna immobilization and fullerene accumulation was also measured in each of the lake waters. Depending on the characteristics of the lake waters, fullerenes either exhibited extended water stability or settled rapidly; in all waters, there was a fraction that remained stable after 1 yr. Water stability was affected by the quality and m…
Piezoresistive Sensors from Bithiophene-fulleropyrrolidine Bisadducts Thin-Films
The phenomenon of piezoresistivity in materials is based on the separation of conductive domains triggered by mechanical strains, resulting in a variation of the electrical resistance.1 This property is at the core of sensors for wearable electronics, e-skins, human motion detectors and machine learning devices.2 Fundamental requirements include lightness, good transparency, high flexibility and sensitivity to tiny deformations. However, the fabrication of a system integrating all these features is challenging. Herein, we show a semitransparent piezoresistive sensor realized by an electropolymerized bithiophene‐fulleropyrrolidine bisadduct onto ITO/PET3 (see Figure 1a). The good outcome of …
Substrate templating guides the photoinduced reaction of C60on calcite
2014
cited By 7; International audience; A substrate-guided photochemical reaction of C60 fullerenes on calcite, a bulk insulator, investigated by non-contact atomic force microscopy is presented. The success of the covalent linkage is evident from a shortening of the intermolecular distances, which is clearly expressed by the disappearance of the moiré pattern. Furthermore, UV/Vis spectroscopy and mass spectrometry measurements carried out on thick films demonstrate the ability of our setup for initiating the photoinduced reaction. The irradiation of C60 results in well-oriented covalently linked domains. The orientation of these domains is dictated by the lattice dimensions of the underlying c…
Distribution of fullerenes (nC60) between sediment and water in freshwaters
2014
Abstract Depending on environmental conditions, fullerenes (nC 60 ) have the potential to settle to the bottom sediments. In this study the distribution of nC 60 was investigated in the labile zone between sediment and water. Three freshwater–sediment systems representing oligohumic, mesohumic, and polyhumic lakes with varying sediment composition and structure were used to investigate the target of fullerenes. The largest portion of water suspended fullerenes was found in the sediment, but a part re-suspended relatively quickly to water-stabile particles associated with natural particles. Rapid initial re-suspending was followed by a slower one offering a continuous pathway to the water ph…
Hydrogen Bonding Donor–Acceptor Carbon Nanostructure
2012
The natural process of photosynthesis is paradigmatic in converting sunlight into energy. This complicated process requires a cascade of energy- and electron-transfer events in a highly organised matrix of electron–donor, electron–acceptor and antennae units and has prompted researchers to emulate it. In fact, energy- and electron-transfer processes play a pivotal role in molecular-scale optoelectronics. In this chapter we compile a number of remarkable examples of noncovalent aggregates formed by the combination of carbon-based electroactive species (fullerenes and carbon nanotubes) hydrogen bonded with a variety of moieties. We will show that: (a) the connection of complementary electroac…
Behaviour of Nanomaterials in the Environment: A Study of Interaction between Humic Acids and Fullerene C60
2010
Interaction between buckminsterfullerene and humic substances of different origin was investigated using fluorescence spectrometry as function of concentration of humic substances, pH and ionic strength. Binding constants of humic substances and buckminsterfullerene were calculated. It can be suggested that the complexation was driven by hydrophobic interaction depending on properties of the interacting compounds. Hydrophobic interaction model was indicated by linear Stern–Volmer plot, and high Kd values characterized interaction between buckminsterfullerene and humic acids. The results of this study support the development of understanding of fate of nanomaterials in environment as well as…