Optical Properties and Light-Induced Charge Transfer in Selected Aromatic C60 Fullerene Derivatives and in Their Bulk Heterojunctions with Poly(3-Hexylthiophene).

Fullerene derivatives offer great scope for modification of the basic molecule, often called a buckyball. In recent years, they have been the subject of numerous studies, in particular in terms of their applications, including in solar cells. Here, the properties of four recently synthesized fullerene C60 derivatives were examined regarding their optical properties and the efficiency of the charge transfer process, both in fullerene derivatives themselves and in their heterojunctions with poly (3-hexylthiophene). Optical absorption, electron spin resonance (ESR), and time-resolved photoluminescence (TRPL) techniques were applied to study the synthesized molecules. It was shown that the absorption processes in fullerene derivatives are dominated by absorption of the fullerene cage and do not significantly depend on the type of the derivative. It was also found by ESR and TRPL studies that asymmetrical, dipole-like derivatives exhibit stronger light-induced charge transfer properties than their symmetrical counterparts. The observed inhomogeneous broadening of the ESR lines indicated a large disorder of all polymer-fullerene derivative blends. The density functional theory was applied to explain the results of the optical absorption experiments.

Novel C60 Fullerenol-Gentamicin Conjugate-Physicochemical Characterization and Evaluation of Antibacterial and Cytotoxic Properties.

This study aimed to develop, characterize, and evaluate antibacterial and cytotoxic properties of novel fullerene derivative composed of C60 fullerenol and standard aminoglycoside antibiotic-gentamicin (C60 fullerenol-gentamicin conjugate). The successful introduction of gentamicin to fullerenol was confirmed by X-ray photoelectron spectroscopy which together with thermogravimetric and spectroscopic analysis revealing the formula of the composition as C60(OH)12(GLYMO)11(Gentamicin)0.8. The dynamic light scattering (DLS) revealed that conjugate possessed ability to form agglomerates in water (size around 115 nm), while Zeta potential measurements demonstrated that such agglomerates possessed neutral character. In vitro biological assays indicated that obtained C60 fullerenol-gentamicin conjugate possessed the same antibacterial activity as standard gentamicin against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli, which proves that combination of fullerenol with gentamicin does not cause the loss of antibacterial activity of antibiotic. Moreover, cytotoxicity assessment demonstrated that obtained fullerenol-gentamicin derivative did not decrease viability of normal human fibroblasts (model eukaryotic cells) compared to control fibroblasts. Thus, taking into account all of the results, it can be stated that this research presents effective method to fabricate C60 fullerenol-gentamicin conjugate and proves that such derivative possesses desired antibacterial properties without unfavorable cytotoxic effects towards eukaryotic cells in vitro. These promising preliminary results indicate that obtained C60 fullerenol-gentamicin conjugate could have biomedical potential. It may be presumed that obtained fullerenol may be used as an effective carrier for antibiotic, and developed fullerenol-gentamicin conjugate may be apply locally (i.e., at the wound site). Moreover, in future we will evaluate possibility of its applications in inter alia tissue engineering, namely as a component of wound dressings and implantable biomaterials.

Crystal Structure Determination of 4-[(Di-p-tolyl-amino)-benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine along with Selected Properties of Imine in Neutral and Protonated Form with Camforosulphonic Acid: Theoretical and Experimental Studies.

The crystal structure was determined for the first time for 4-[(di-p-tolyl-amino)benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine (trans-PPL9) by X-ray diffraction. The imine crystallized in the monoclinic P21/n space group with a = 18.9567(7) Å, b = 6.18597(17) Å, c = 22.5897(7) Å, and ß = 114.009(4)°. Intermolecular interactions in the PPL9 crystal were only weak C-H⋯N hydrogen bonds investigated using the Hirshfeld surface. The electronic and geometric structure of the imine were investigated by the density functional theory and the time-dependent density-functional theory. The properties of the imine in neutral and protonated form with camforosulphonic acid (CSA) were investigated using cyclic voltammetry, UV-vis and 1H NMR spectroscopy. Theoretical and experimental studies showed that for the 1:1 molar ratio the protonation occured on nitrogen in pyridine in the PPL9 structure, as an effect of Brönsted acid-base interactions. Thermographic camera was used to defined defects in constructed simple devices with ITO/PPL9 (or PPL9:CSA)/Ag/ITO architecture. In conclusion, a thermally stable imine was synthesized in crystalline form and by CSA doping, a modification of absorption spectra together with reduction of overheating process was observed, suggesting its potential application in optoelectronics.

Mono- and Di-Pyrene [60]Fullerene and [70]Fullerene Derivatives as Potential Components for Photovoltaic Devices.

In the present work, we report the successful synthesis and characterization of six (two new) fullerene mono- and di-pyrene derivatives based on C60 and C70 fullerenes. The synthesized compounds were characterized by spectral methods (ESI-MS, 1H-NMR, 13C-NMR, UV-Vis, FT-IR, photoluminescence and photocurrent spectroscopy). The energy of HOMO and LUMO levels and the band gaps were determined from cyclic voltammetry and compared with the theoretical values calculated according to the DFT/B3LYP/6-31G(d) and DFT/PBE/6-311G(d,p) approach for fully optimized molecular structures at the DFT/B3LYP/6-31G(d) level. Efficiency of solar cells made of PTB7: C60 and C70 fullerene pyrene derivatives were analyzed based on the determined energy levels of the HOMO and LUMO orbitals of the derivatives as well as the extensive spectral results of fullerene derivatives and their mixtures with PTB7. As a result, we found that the electronic and spectral properties, on which the efficiency of a photovoltaic cell is believed to depend, slightly changes with the number and type of pyrene substituents on the fullerene core. The efficiency of constructed solar cells largely depends on the homogeneity of the photovoltaic layer, which, in turn, is a derivative of the solubility of fullerene derivatives in the solvent used to apply these layers by spincoating.

Beneficial Influence of Water-Soluble PEG-Functionalized C60 Fullerene on Human Osteoblast Growth In Vitro.

The purpose of this study was to make an initial assessment of new PEG (polyethylene glycol)-functionalized C60 fullerene derivative for potential bone tissue engineering applications. Thus, Fourier Transform Infrared spectroscopy analysis, thermogravimetric analysis, and cyclic voltammetry measurement were performed. Moreover, cell culture experiments in vitro were carried out using normal human osteoblasts. Cell viability and proliferation were evaluated using colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test as well as by fluorescent staining. It was demonstrated that resultant derivative possessed good solubility in water, high temperature stability, and retained favorable electron accepting properties of C60 fullerene core. Most important, new fullerene derivatives at low concentrations did not exhibit cytotoxic effect and supported osteoblast proliferation compared to control. Thanks to all mentioned properties of new PEG-functionalized C60 fullerene derivative, it seems that it could be used as a component of polymer-based bone scaffolds in order to enhance their biological properties.

A comprehensive optical and electrical study of unsymmetrical imine with four thiophene rings and their binary and ternary compositions with PTB7 and PC70BM towards organic photovoltaics.

A new unsymmetrical imine with four thiophene rings was synthesized in a one-step reaction, starting from the commercially available and relatively inexpensive reagents. The obtained imine in the form of thin films exhibited photoluminescence properties in the 1.8-2.4 eV energy range and a photoluminescence lifetime of about 0.3 ns. The HOMO and LUMO levels of the imine determined by cyclic voltammetry were at about -5.19 eV and -3.05 eV, respectively. The density functional theory was applied to calculate the geometric and electronic structure of the imine. The UV-Vis spectra showed that the absorption range of the imine overlaps with that of PC70BM, and the absorption peak at the maximum of the imine at 424 nm is located between the two maxima at 404 nm and 461 nm of the fullerene derivative. The electron acceptor and donor activity of the imine was tested in the solar cell architecture: glass/ITO/PEDOT:PSS/active layer/In/Al. The best photovoltaic parameters, with very good reproducibility for each 8 pixels in the cell, were found for the active layer based on ternary mixture PTB7:PC70BM:imine at a weight ratio 8 : 13 : 1, with the power conversion efficiency of about 4%. The external quantum efficiency of devices with the imine was found to be about 40% at 3.3 eV. The thermal imaging together with the recorded current response at increasing potential showed that the presence of imine in the composition has a beneficial impact in terms of current flow stability at temperatures above 200 °C, compared to two component layers with the same imine as an additive.

UV-Vis Absorption Properties of New Aromatic Imines and Their Compositions with Poly({4,8-bis[(2-Ethylhexyl)oxy]Benzo[1,2-b:4,5-b']Dithiophene-2,6-diyl}{3-Fluoro-2-[(2-Ethylhexyl)Carbonyl]Thieno[3,4-b]Thiophenediyl}).

In this paper, four new aromatic imines containing at least one thiazole-based heterocycle were analyzed in detail by UV-Vis spectroscopy, taking into consideration their chemical structures and interactions with PTB7, a known polymeric electron donor widely used in bulk heterojunction organic solar cells. It is demonstrated that the absorption spectra of the investigated active compositions can be modified not only by changing the chemical structure of imine, but also via formulations with PTB7. For all investigated imines and PTB7:imine compositions, calibration curves were obtained in order to find the optimum concentration in the composition with PTB7 for expansion and optimization of absorption spectra. All imines and PTB7:imine compositions were investigated in 1,2-dichlorobenzene by UV-Vis spectroscopy in various concentrations, monitoring the changes in the π-π* and n-π* transitions. With increasing imine concentrations, we did not observe changes in absorption maxima, while with increasing imine concentrations, a hypochromic effect was observed. Finally, we could conclude that all investigated compositions exhibited wide absorptions of up to 800 nm and isosbestic points in the range of 440-540 nm, confirming changes in the macromolecular organization of the tested compounds. The theoretical calculations of their vibration spectra (FTIR) and LUMO-HOMO levels by Density Functional Theory (DFT) methods are also provided. Finally, IR thermal images were measured for organic devices based on imines and the imine:PTB7 composite.

Gastropods from the Late Jurassic-Early Cretaceous seep deposits in Spitsbergen, Svalbard.

Eleven gastropod species from seven latest Jurassic-earliest Cretaceous hydrocarbon seep deposits from central Spitsbergen, Svalbard are described and illustrated. Six new species and one new genus are introduced. Sassenfjordia gen. nov. is tentatively classified as a naticoid and is characterized by a naticiform gross teleoconch morphology and a large protoconch ornamented with spiral ribs, similar to those present in the subfamily Sininae. The patellogastropod ?Pectinodonta borealis sp. nov. represents the oldest occurrence of pectinodontid limpets in chemosynthesis-based associations. The colloniid Hikidea svalbardensis sp. nov. is the oldest confirmed occurrence of this genus so far. The eucyclid Eucycloidea bitneri sp. nov. is the second report of an occurrence of this genus at hydrocarbon seeps (both of which come from the Paleo-Barents Sea). Abyssomelania sp. is the third known, and the oldest occurrence of this genus. Hudlestoniella hammeri sp. nov. represents another occurrence of this genus at seeps in the Paleo-Barents Sea; its current higher-rank assignment is reviewed herein. It may belong either to the rissoids, as previously suggested, or to the abyssochrysoids (or zygopleurids). A fossil identified as Cretadmete sp. is here classified in the Purpurinidae, a family of stem neogastropods or tonnoideans. The heterobranch Hyalogyrina knorringfjelletensis sp. nov. is the oldest occurrence of hyalogyrinids in chemosynthesis-based associations. Several oldest occurrences of seep taxa in moderately shallow-water seeps in Spitsbergen suggest that the previously questioned onshore-offshore hypothesis of seep and vent colonization should be carefully re-investigated.

TEMPO functionalized C60 fullerene deposited on gold surface for catalytic oxidation of selected alcohols.

C60TEMPO10 catalytic system linked to a microspherical gold support through a covalent S-Au bond was developed. The C60TEMPO10@Au composite catalyst had a particle size of 0.5-0.8 µm and was covered with the fullerenes derivative of 2.3 nm diameter bearing ten nitroxyl groups; the organic film showed up to 50 nm thickness. The catalytic composite allowed for the oxidation under mild conditions of various primary and secondary alcohols to the corresponding aldehyde and ketone analogues with efficiencies as high as 79-98%, thus giving values typical for homogeneous catalysis, while retaining at the same time all the advantages of heterogeneous catalysis, e.g., easy separation by filtration from the reaction mixture. The catalytic activity of the resulting system was studied by means of high pressure liquid chromatography. A redox mechanism was proposed for the process. In the catalytic cycle of the oxidation process, the TEMPO moiety was continuously regenerated in situ with an applied primary oxidant, for example, O2/Fe3+ system. The new intermediate composite components and the final catalyst were characterized by various spectroscopic methods and thermogravimetry. Graphical abstractᅟ.

The paleoecology, habitats, and stratigraphic range of the enigmatic cretaceous brachiopod peregrinella.

Modern and Cenozoic deep-sea hydrothermal-vent and methane-seep communities are dominated by large tubeworms, bivalves and gastropods. In contrast, many Early Cretaceous seep communities were dominated by the largest Mesozoic rhynchonellid brachiopod, the dimerelloid Peregrinella, the paleoecologic and evolutionary traits of which are still poorly understood. We investigated the nature of Peregrinella based on 11 occurrences world wide and a literature survey. All in situ occurrences of Peregrinella were confirmed as methane-seep deposits, supporting the view that Peregrinella lived exclusively at methane seeps. Strontium isotope stratigraphy indicates that Peregrinella originated in the late Berriasian and disappeared after the early Hauterivian, giving it a geologic range of ca. 9.0 (+1.45/-0.85) million years. This range is similar to that of rhynchonellid brachiopod genera in general, and in this respect Peregrinella differs from seep-inhabiting mollusks, which have, on average, longer geologic ranges than marine mollusks in general. Furthermore, we found that (1) Peregrinella grew to larger sizes at passive continental margins than at active margins; (2) it grew to larger sizes at sites with diffusive seepage than at sites with advective fluid flow; (3) despite its commonly huge numerical abundance, its presence had no discernible impact on the diversity of other taxa at seep sites, including infaunal chemosymbiotic bivalves; and (4) neither its appearance nor its extinction coincides with those of other seep-restricted taxa or with global extinction events during the late Mesozoic. A preference of Peregrinella for diffusive seepage is inferred from the larger average sizes of Peregrinella at sites with more microcrystalline carbonate (micrite) and less seep cements. Because other seep-inhabiting brachiopods occur at sites where such cements are very abundant, we speculate that the various vent- and seep-inhabiting dimerelloid brachiopods since Devonian time may have adapted to these environments in more than one way.

Mollusks from late Mesozoic seep deposits, chiefly in California.

Twenty-nine mollusk species from Late Jurassic to Eocene hydrocarbon seep deposits from California (USA), Japan, New Zealand, and Barbados are described and illustrated. Twenty species belong to Gastropoda and nine to Bivalvia. Seven new species, three new genera, and one new family are introduced. The gastropod Hikidea gen. nov. includes smooth-shelled Cantrainea-like colloniins from Cretaceous hydrocarbon seeps and plesiosaur falls. Hikidea osoensis sp. nov. is the oldest species of this genus. Chilodonta? reticulata sp. nov. is a distinctive vetigastropod though its supraspecific position is unclear. Phanerolepida onoensis sp. nov. is the first species of this colloniin genus from a seep deposit. We describe two new genera of Hokkaidoconchidae: Abyssomelania gen. nov. and Ascheria gen. nov.; this family includes now four genera (including Hokkaidoconcha and Humptulipsia) and ranges from the Late Jurassic to the Eocene. Abyssomelania is characterized by a large, high-spired shell and unusual widely-spaced prosocline riblets (here called abyssomelaniid riblets). Abyssomelania is represented by two new species: A. cramptoni sp. nov. from the Late Cretaceous of New Zealand and A. campbellae sp. nov. from the Early Cretaceous of California. Ascheria gen. nov. is characterized by a large high-spired cerithiform shell, a subsutural constriction, and mostly reticulate ornament. Two nominate species are included: Ascheria gigantea (Kiel et al., 2008) and A. eucosmeta (Ascher, 1906), both of Early Cretaceous age. Two further species potentially belonging to Ascheria from the Eocene of Barbados are reported in open nomenclature and are re-illustrated and re-described for comparison. Humtulipsia nobuharai sp. nov. is described based on specimens from the Campanian-Maastrichtian Sada Limestone seep deposit in Japan. The new family Paskentanidae fam. nov. is introduced for the genera Paskentana and Atresius. The species of this family are characterized by thin-shelled, broad to high-spired littoriniform adult shells and juvenile teleoconchs with a subsutural ramp. Paskentana hamiltonensis sp. nov. is described from the Early Cretaceous of California. Ataphrus is considered to represent a nomen dubium because its type species is poorly preserved and there are uncertainties regarding its type locality and age. The bivalves reported herein belong to known species, but our new material revealed additional characters, and/or their supraspecific position is revised and new combinations are proposed: Solemya stantoni Vokes, 1955 is transferred to Acharax, Nucula gabbi Stanton, 1895 is transferred to Leionucula, Pecten complexicostata Gabb, 1869 is transferred to Lyriochlamys, Astarte californica Stanton, 1895 is transferred to Neocrassina, Astarte trapezoidalis Stanton, 1895 is transferred to Oxyeurax, and Corbula? persulcata Stanton, 1895 is transferred to Cuspidaria?