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Fullerene Molecule (fullerene + molecule)
Selected AbstractsWell-Defined Fullerene Nanowire Arrays,ADVANCED FUNCTIONAL MATERIALS, Issue 8 2003Y.-G. Guo Abstract Fullerene nanowire arrays with well-defined size and length have been prepared by a controllable technique. Fullerene molecules such as C60 are introduced into the pores of anodic aluminum oxide (AAO) templates under a direct current (DC) electric field and polymerized in the pores. Structure analysis shows that the C60 nanowires are mainly polycrystalline, and a rhombohedral polymeric phase is observed in their vibration spectra. The electrical conductivity of so-prepared nanowire arrays show a semiconducting behavior. The ability to fabricate the fullerene nanowire arrays with controlled structures represents an important step toward the development of chemical sensors and nanoscale electronic devices based on fullerenes. [source] Synthesis, Crystal Structure, and Optical Properties of a New Molecular Complex of C60 with a Covalently Linked (FeIIITPP)2O DimerEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 21 2003Aleksey L. Litvinov Abstract A new molecular complex of C60 with covalently linked ,-oxo dimer (FeIIITPP)2O are (TPP = tetraphenylporphyrin) was obtained. The complex has a neutral ground state and is formed mainly by van der Waals forces. The X-ray analysis of the crystal structure of the complex showed it to have isolated packing of fullerenes in which each fullerene molecule is embraced in a pocket built by porphyrins. Optical properties and EPR behavior of the complex are described. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Bimolecular Crystals of Fullerenes in Conjugated Polymers and the Implications of Molecular Mixing for Solar CellsADVANCED FUNCTIONAL MATERIALS, Issue 8 2009A. C. Mayer The performance of polymer:fullerene bulk heterojunction solar cells is heavily influenced by the interpenetrating nanostructure formed by the two semiconductors because the size of the phases, the nature of the interface, and molecular packing affect exciton dissociation, recombination, and charge transport. Here, X-ray diffraction is used to demonstrate the formation of stable, well-ordered bimolecular crystals of fullerene intercalated between the side-chains of the semiconducting polymer poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2- b]thiophene. It is shown that fullerene intercalation is general and is likely to occur in blends with both amorphous and semicrystalline polymers when there is enough free volume between the side-chains to accommodate the fullerene molecule. These findings offer explanations for why luminescence is completely quenched in crystals much larger than exciton diffusion lengths, how the hole mobility of poly(2-methoxy-5-(3,,7,-dimethyloxy)-p-phylene vinylene) increases by over 2 orders of magnitude when blended with fullerene derivatives, and why large-scale phase separation occurs in some polymer:fullerene blend ratios while thermodynamically stable mixing on the molecular scale occurs for others. Furthermore, it is shown that intercalation of fullerenes between side chains mostly determines the optimum polymer:fullerene blending ratios. These discoveries suggest a method of intentionally designing bimolecular crystals and tuning their properties to create novel materials for photovoltaic and other applications. [source] Optical spectra and covalent chemistry of fulleropyrrolidinesINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 14 2007B. S. Razbirin Abstract Low-temperature vibronic spectra of two fulleropyrrolidines (1-methyl-3,4-FP and 1-methyl-2(4-pyridine)-3,4-FP) embedded in crystalline toluene matrix have been studied. Two-component composition of the spectra has been established and charge-transfer-excitation origin of the structureless component has been suggested. Fine-structured Shpol'skii spectra were observed for 1-methyl-3,4-FP, which made possible to perform the vibrational analysis of its vibronic spectra. General similarities of the absorption spectra of fulleropyrrolidines and C60 molecules along with significant difference in their details have been discussed. A detailed interpretation of the C60 spectra serves as a basis for analyzing the spectra of the derivatives. Quantum-chemical study is based on the effectively-unpaired-electron concept for the fullerene molecule. Computations have been performed for the singlet states of the molecules in unrestricted Hartree,Fock approximation implemented in AM1 semiempirical quantum chemical codes of the CLUSTER-Z1 software. The population of the HOMO and LUMO of the molecules under study alongside with the lowering of the molecules symmetry have been proposed to explain the spectral features observed. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [source] C60 Nanostructures for Applications in Information Technology,ADVANCED ENGINEERING MATERIALS, Issue 4 2009Oliver Senftleben Carbon nanostructures,such as nanotubes, fullerenes, or graphene sheets,are studied widely in search of future applications in electronic devices. In our work, we demonstrate the possibility of embedding C60 fullerene molecules into a crystalline silicon matrix to form highly confined carbon- , -layers as well as into an amorphous SiO2 gate stack for possible application as a charge storage device. [source] Charge Transfer Excitons in Polymer/Fullerene Blends: The Role of Morphology and Polymer Chain ConformationADVANCED FUNCTIONAL MATERIALS, Issue 22 2009Markus Hallermann Abstract Here, it is shown how carrier recombination through charge transfer excitons between conjugated polymers and fullerene molecules is mainly controlled by the intrachain conformation of the polymer, and to a limited extent by the mesoscopic morphology of the blend. This experimental result is obtained by combining near-infrared photoluminescence spectroscopy and transmission electron microscopy, which are sensitive to charge transfer exciton emission and morphology, respectively. The photoluminescence intensity of the charge transfer exciton is correlated to the degree of intrachain order of the polymer, highlighting an important aspect for understanding and limiting carrier recombination in organic photovoltaics. [source] Magnetic Properties and Crystal Structure of Solvent-Free Sc@C82 Metallofullerene MicrocrystalsCHEMPHYSCHEM, Issue 7 2007Yasuhiro Ito Abstract Magnetic properties of solvent-free crystals of the endohedral Sc@C82 are investigated by SQUID and X-ray powder diffraction. We find that the crystal is a paramagnet and the magnetic susceptibility decreases from 150 K with evidence of antiferromagnetic-like interactions by slow cooling. X-ray crystal analysis reveals the presence of a phase transition at 150 K, which is attributed to an orientational ordering transition of the fullerene molecules. At low temperatures we find a magnetic metastable state that can be controlled by the cooling rate. The metastable state can be formed by rapid cooling. The direction of Sc@C82 molecular axis in the crystals is disordered in the metastable state, and the susceptibility is higher than that in the slow cooling case at low temperature. [source] | |||||||||||||