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Kengo Masuda, Masanori Nagatomo, Masayuki Inoue
Pentoses and hexoses contain more than three oxygen-bearing stereocentres and are ideal starting materials for the synthesis of multiply oxygenated natural products such as sagittamide D, maitotoxin and hikizimycin. Here we demonstrate new radical-radical homocoupling reactions of sugar derivatives with minimal perturbation of their chiral centres. The radical exchange procedure using Et3B/O2 converted sugar-derived α-alkoxyacyl tellurides into α-alkoxy radicals via decarbonylation and rapidly dimerized the monomeric radicals...
March 2017: Nature Chemistry
Ling Wang, Yitong Wang, Jingcheng Hao, Shuli Dong
We create the dual-responsive nanovehicle that can effectively combine and abundantly utilize magnetic and glutathione (GSH)-reductive triggers to control the drug delivery and achieve more intelligent and powerful targeting. In the nanovehicles, paramagnetic fullerene (C60@CTAF) was prepared via one-step modification of fullerene with magnetic surfactant CTAF by hydrophobic interaction for the first time. The perfect conjugation of C60 and CTAF increased the solubility or dispersity of fullerenes and qualify CTAF with more powerful assembly capability with DNA...
February 21, 2017: Biomacromolecules
Satoshi Kaneko, Yoshifumi Hashikawa, Shintaro Fujii, Yasujiro Murata, Manabu Kiguchi
A water molecule exhibits characteristic properties on the basis of hydrogen-bondings. In the past decade, a single water molecule placed in the non-hydrogen-bonding environment has attracted growing attention. To reveal fundamental properties of a single water molecule, endohedral fullerene H2O@C60 becomes an ideal and suitable model. We examined the electronic properties of H2O@C60 by applying the single-molecule measurement. The conductance of a single molecular junction based on H2O@C60 was found to be comparable with that of empty C60...
February 20, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Andrei A Mosunov, Irina S Pashkova, Maria Sidorova, Artem Pronozin, Anastasia O Lantushenko, Yuriy I Prylutskyy, John A Parkinson, Maxim P Evstigneev
We report a new analytical method that allows the determination of the magnitude of the equilibrium constant of complexation, Kh, of small molecules to C60 fullerene in aqueous solution. The developed method is based on the up-scaled model of C60 fullerene-ligand complexation and contains the full set of equations needed to fit titration datasets arising from different experimental methods (UV-Vis spectroscopy, (1)H NMR spectroscopy, diffusion ordered NMR spectroscopy, DLS). The up-scaled model takes into consideration the specificity of C60 fullerene aggregation in aqueous solution and allows the highly dispersed nature of C60 fullerene cluster distribution to be accounted for...
February 20, 2017: Physical Chemistry Chemical Physics: PCCP
Andrea Carboni, Rick Helmus, John R Parsons, Karsten Kalbitz, Pim de Voogt
Carbon-based nanomaterials, such as C60 fullerenes, are expected to accumulate in soil due to direct release and deposition from the atmosphere. However, little is known about the environmental fate of these nanoparticles which may be susceptible to photochemical and microbial degradation. In the present work, C60 was incubated for a period of 28 days and irradiated with UVA light. Three experiments were carried out where the fullerenes were either spiked onto a glass surface or added to quartz sand or sandy soil samples...
February 2, 2017: Chemosphere
Masanori Yamamoto, Jens Föhlinger, Jonas Petersson, Leif Hammarström, Hiroshi Imahori
A ruthenium complex, porphyrin sensitizer, fullerene acceptor molecular pentad has been synthesized and a long-lived hole-electron pair was achieved in aqueous solution by photoinduced multistep electron transfer: Upon irradiation by visible light, the excited-state of a zinc porphyrin ((1) ZnP*) was quenched by fullerene (C60 ) to afford a radical ion pair, (1,3) (ZnP(.+) -C60(.-) ). This was followed by the subsequent electron transfer from a water oxidation catalyst unit (Ru(II) ) to ZnP(.+) to give the long-lived charge-separated state, Ru(III) -ZnP-C60(...
February 14, 2017: Angewandte Chemie
Pin Wu, Hua-Ming Xiao, Jun Ding, Qian-Yun Deng, Fang Zheng, Yu-Qi Feng
Quantification of low molecular weight compounds (<800 Da) using matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI MS) is challenging due to the matrix signal interference at low m/z region and poor reproducibility of MS responses. In this study, a C60 labeling-MALDI MS strategy was proposed for the fast, sensitive and reliable determination of amino acids (AAs) in biofluids. An N-hydroxysuccinimide functionalized C60 was synthesized as the labeling reagent and added as an 880 Da tag to AAs; a carboxyl acid containing C60 was employed as the internal standards to normalize MS variations...
April 1, 2017: Analytica Chimica Acta
Chuan-Ding Dong, Wichard J D Beenken
We investigated the intercalation of C60 into poly(p-anthracene-ethynylene)-alt-poly(p-phenylene-vinylene) copolymers layers by density functional theory calculations in respect of crystal structures and electronic band structures. Based on the experimental observations, we found that the copolymer with branched side chains substituted next to the anthracene units and the linear side chains substituted to the vinylene units has a better tendency to intercalate with C60 than the reversely substituted copolymer...
February 22, 2017: Journal of Physical Chemistry. B
Hung Le, Nguyet Pham
In this study, we examine the adsorptions of Ni, Pd, Pt clusters on C60 using a computational approach. Our calculation results show that the base structure of C60 can host Nin/Pdn/Ptn (n=1-4) clusters with good adsorption stability and the complexes establishes either two or no unpaired electrons. The binding energy of Pd and Pt clusters increases as the number of metal atom increases, which implies that the coverage of C60 with Pd or Pt prefers to establish a large-size metal cluster. A single metal atom favorably occupies the C-C bridge site...
February 9, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Yuri Mackeyev, Colette Mark, Natasha Kumar, Rita E Serda
: The use of non-invasive radiofrequency (RF) energy to induce mild thermal and non-thermal effects in cancer tissue is under study as an adjuvant to chemo, radio or immuno therapy. This study examines cell specific sensitivities to RF exposure and the potential of nanoparticles to elevate heating rates or enhance biological effects. Increases in the heating rate of water in an RF field operating at 13.56MHz (0.004-0.028°C/s) were positively correlated with concentration of hybrid nanoparticles (1-10mg/ml) consisting of water soluble malonodiserinolamide [60]fullerene (C60-ser) conjugated to the surface of mesoporous silica nanoparticles (SiO2-C60)...
February 5, 2017: Acta Biomaterialia
C Lorch, J Novák, R Banerjee, S Weimer, J Dieterle, C Frank, A Hinderhofer, A Gerlach, F Carla, F Schreiber
We investigated the growth of the two phase-separating materials diindenoperylene (DIP) and buckminsterfullerene C60 with different mixing ratio in real-time and in situ by X-ray scattering experiments. We found that at room temperature, mixtures with an excess of DIP show a growth mode which is very close to the perfect layer-by-layer limit with DIP crystallites forming over the entire film thickness. An unexpected increase in the island size is observed for these mixtures as a function of film thickness. On the other hand, equimolar and C60 dominated mixtures grow with poor crystallinity but form very smooth films...
February 7, 2017: Journal of Chemical Physics
Hong-Tao Xue, Gabriele Boschetto, Michal Krompiec, Graham E Morse, Fu-Ling Tang, Chris-Kriton Skylaris
In this work, the crystal properties, HOMO and LUMO energies, band gaps, density of states, as well as the optical absorption spectra of fullerene C60 and its derivative phenyl-C61-butyric-acid-methyl-ester (PCBM) co-crystallised with various solvents such as benzene, biphenyl, cyclohexane, and chlorobenzene were investigated computationally using linear-scaling density functional theory with plane waves as implemented in the ONETEP program. Such solvates are useful materials as electron acceptors for organic photovoltaic (OPV) devices...
February 7, 2017: Physical Chemistry Chemical Physics: PCCP
Fei Gao, Andrew V Teplyakov
The development of oxygen-free organic-inorganic interfaces has led to new schemes for the functionalization of silicon surfaces with nitrogen-based chemical groups. However, building layers of large structures directly on this functionalized surface has remained elusive. This work confirms the path to form a stable interface between silicon and buckminsterfullerene C60 based on covalent chemical bonds. The starting point for this modification is the hydrazine-reacted Si(111) surface with the diamine functionality, which is further reacted directly with the C60 molecules...
February 13, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Vinit Pundir, Chelat Narayana Panicker Ramachandran
Density functional studies are performed for the boron atom encapsulated complexes of C60, C59B and C59N using B3LYP and B3LYP-GD2 functionals with 6-311G* basis set. The study shows that the complexes B@C59B and B@C59N can exist in different forms which differ in their structure, electronic and magnetic properties. The nature of interaction between the guest and the host is analyzed based on the stabilization energies of complexes for their different spin states. The electronic properties such as vertical electron affinity (VEA), vertical ionization energy (VIE) and energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the complexes are calculated...
February 2, 2017: Journal of Physical Chemistry. A
Francis D'Souza, M A Collini, M J Thomas, V Bandi, P A Karr
The efficiency and mechanism of electron- and energy transfer events occurring in both in natural and synthetic donor-acceptor systems depend on their distance, relative orientation, and the nature of the surrounding media. Fundamental knowledge gained from model studies is key in building efficient energy harvesting and optoelectronic devices. In our continued effort to build donor-acceptor systems using near-IR sensitizers, in the present study, we report ground and excited state charge transfer in newly synthesized, directly linked, tetrads featuring bisdonor (donor = phenothiazine and ferrocene), BF2-chelated azadipyrromethane (azaBODIPY) and C60 entities...
February 2, 2017: Chemistry: a European Journal
Vasily Lavrentiev, Alexandr Stupakov, Inna Lavrentieva, Mykhaylo Motylenko, Mykhailo Barchuk, David Rafaja
We report on establishing an exclusive magnetic effect in the air-exposed CoxC60 nanocomposites (x>2) created through self-assembling in the depositing mixture. In order to verify the influence of ambient air on the CoxC60 mixture film we have studied in details the film magnetization at rather low temperatures providing their ferromagnetic behavior. Looking for possible exchange bias effect, we distinguished a certainly vertical shift of the hysteresis loops recorded for the air-exposed CoxC60 films in the field cooling (FC) regime...
February 1, 2017: Nanotechnology
Tsukasa Futagoishi, Michihisa Murata, Atsushi Wakamiya, Yasujiro Murata
Methanol (CH3 OH) and formaldehyde (H2 CO) molecules were inserted into an open-cage C60 derivative with a large opening, under high-pressure and high-temperature conditions in solution. Isolation of their molecular complexes in pure form was achieved by the use of recycling HPLC with Buckyprep columns. (1) H NMR spectroscopy, single-crystal X-ray diffraction studies, and DFT calculations revealed the orientation of the encapsulated CH3 OH and H2 CO, both in solution and in the solid state, and the results show that the CH3 group of the CH3 OH and the carbonyl group of the H2 CO point to the bottom of the cages...
March 1, 2017: Angewandte Chemie
Michio Katouda, Takahito Nakajima
A massively parallel algorithm of the analytical energy gradient calculations based the resolution of identity Møller-Plesset perturbation (RI-MP2) method from the restricted Hartree-Fock reference is presented for geometry optimization calculations and one-electron property calculations of large molecules. This algorithm is designed for massively parallel computation on multicore supercomputers applying the Message Passing Interface (MPI) and Open Multi-Processing (OpenMP) hybrid parallel programming model...
March 30, 2017: Journal of Computational Chemistry
Yixin Yan, Yakun Yuan, Baomin Wang, Venkatraman Gopalan, Noel C Giebink
Modulating the second-order nonlinear optical susceptibility (χ((2))) of materials at the nanoscale represents an ongoing technological challenge for a variety of integrated frequency conversion and nonlinear nanophotonic applications. Here we exploit the large hyperpolarizability of intermolecular charge transfer states, naturally aligned at an organic semiconductor donor-acceptor (DA) interface, as a means to control the magnitude and sign of χ((2)) at the nanoscale. Focusing initially on a single pentacene-C60 DA interface, we confirm that the charge transfer transition is strongly aligned orthogonal to the heterojunction and find that it is responsible for a large interfacial nonlinearity probed via second harmonic generation that is sufficient to achieve d33>10 pm V(-1), when incorporated in a non-centrosymmetric DA multilayer stack...
January 27, 2017: Nature Communications
Lei Hou, John D Fortner, Ximeng Wang, Chengdong Zhang, Lilin Wang, Wei Chen
Accumulation of organic contaminants on fullerene nanoparticles (nC60) may significantly affect the risks of C60 in the environment. The objective of this study was to further understand how the interplay of nC60 formation routes and humic acid modification affects contaminant adsorption of nC60. Specifically, adsorption of 1,2,4,5-tetrachlorobenzene (a model nonionic, hydrophobic organic contaminant) on nC60 was greatly affected by nC60 formation route - the formation route significantly affected the aggregation properties of nC60, thus affecting the available surface area and the extent of adsorption via the pore-filling mechanism...
January 2017: Journal of Environmental Sciences (China)
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