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91.
Xheila Yzeiri Massimo Calamante Alessio Dessì Daniele Franchi Andrea Pucci Francesco Ventura Gianna Reginato Lorenzo Zani Alessandro Mordini 《Molecules (Basel, Switzerland)》2021,26(18)
Organic fluorophores have found broad application as emitters in luminescent solar concentrators (LSCs) for silicon photovoltaics. In particular, the preparation of organic conjugated systems with intense light-harvesting ability, emissions in the deep-red and NIR regions, and large Stokes shift values represent a very challenging undertaking. Here, we report a simple and easy way to prepare three symmetrical donor–acceptor–donor (DAD) organic-emitting materials based on a thienopyrazine core. The central core in the three dyes was modified with the introduction of aromatic substituents, aiming to affect their optical properties. The fluorophores were characterized by spectroscopic studies. In all cases, visible-NIR emissions with large Stokes shifts were found, highlighting these molecules as promising materials for the application in LSCs. 相似文献
92.
Carlo Bruno Eleonora Ussano Gianni Barucca Davide Vanossi Giovanni Valenti Edward A. Jackson Andrea Goldoni Lucio Litti Simona Fermani Luca Pasquali Moreno Meneghetti Claudio Fontanesi Lawrence T. Scott Francesco Paolucci Massimo Marcaccio 《Chemical science》2021,12(23):8048
The presence of non-hexagonal rings in the honeycomb carbon arrangement of graphene produces rippled graphene layers with valuable chemical and physical properties. In principle, a bottom-up approach to introducing distortion from planarity of a graphene sheet can be achieved by careful insertion of curved polyaromatic hydrocarbons during the growth of the lattice. Corannulene, the archetype of such non-planar polyaromatic hydrocarbons, can act as an ideal wrinkling motif in 2D carbon nanostructures. Herein we report an electrochemical bottom-up method to obtain egg-box shaped nanographene structures through a polycondensation of corannulene that produces a new conducting layered material. Characterization of this new polymeric material by electrochemistry, spectroscopy, electron microscopy (SEM and TEM), scanning probe microscopy, and laser desorption-ionization time of flight mass spectrometry provides strong evidence that the anodic polymerization of corannulene, combined with electrochemically induced oxidative cyclodehydrogenations (Scholl reactions), leads to polycorannulene with a wavy graphene-like structure.A bottom-up synthesis of wavy graphene structures obtained through an anodic polymerization process, combined with an electrochemically triggered oxidative cyclodehydrogenation, of the bowl-shaped polyaromatic hydrocarbon corannulene. 相似文献
93.
Luka
orevi Lorenzo Casimiro Nicola Demitri Massimo Baroncini Serena Silvi Francesca Arcudi Alberto Credi Maurizio Prato 《Angewandte Chemie (International ed. in English)》2021,60(1):313-320
Multi‐functionalization and isomer‐purity of fullerenes are crucial tasks for the development of their chemistry in various fields. In both current main approaches—tether‐directed covalent functionalization and supramolecular masks—the control of regioselectivity requires multi‐step synthetic procedures to prepare the desired tether or mask. Herein, we describe light‐responsive tethers, containing an azobenzene photoswitch and two malonate groups, in the double cyclopropanation of [60]fullerene. The formation of the bis‐adducts and their spectroscopic and photochemical properties, as well as the effect of azobenzene photoswitching on the regiochemistry of the bis‐addition, have been studied. The behavior of the tethers depends on the geometry of the connection between the photoactive core and the malonate moieties. One tether lead to a strikingly different adduct distribution for the E and Z isomers, indicating that the covalent bis‐functionalization of C60 can be controlled by light. 相似文献
94.
The effect of energy exchange on the dynamics of the chemisorption of H2 on Pt (111) is studied within a LEPS potential quasi-classical trajectories treatment. The Einstein model is assumed for the solid. The rigidity of the surfaces is shown to be an acceptable approximation. 相似文献
95.
96.
97.
Milan Journal of Mathematics - A locally compact commutative group is compact if and only if its dual group is discrete, in other words if its regular representation is atomic. Nevertheless, there... 相似文献
98.
Anna Laura Segre Fulvio Andruzzi Corrado Barone Massimo Paci Pier Luigi Magagnini 《Journal of Polymer Science.Polymer Physics》1985,23(12):2611-2621
The 13C NMR spectra of aromatic comblike polyesters obtained from 1,2-icosanediol and isomeric phthalic acids are reported and discussed. The analysis shows that the most informative spectral regions are those of the carbonyl and quaternary carbon resonances, whose peak multiplicities have been interpreted in terms of dyad and triad sequences. The results indicate that the extent of structural characterization possible for the polymers examined is dependent on the type of isomerism of the aromatic acid involved. 相似文献
99.
Emo Chiellini Massimo Marchetti Claude Villiers Christian Braud Michel Vert 《European Polymer Journal》1978,14(4):251-256
Maleic anhydride (MAn) was copolymerized in benzene solution at 60° using AIBN with some optically active alkylvinylethers (RVE) having an asymmetric carbon atom at the α, β, γ or δ position with respect to the oxygen atom [R = (S)-1-methylpropyl, (R)-1-methylbutyl, (S)-2-methylbutyl, (S)-3-methylpentyl, (S)-4-methylhexyl, (S)-1-methylheptyl and (S)-3,7-dimethyloctyl]. Chemical compositions and solubilities of the polymeric products as well as optical rotation properties and spectroscopic measurements (i.r. and NMR) confirmed the formation of copolymers with a predominantly alternating structure. Two Cotton effects of low but definite intensity attributable to electronic transitions of carbonyl groups of anhydride moieties were observed between 200 and 250 nm. Failure to achieve complete cleavage of chiral side chains does not enable us to attribute the induced optical activity of anhydride moieties either to the asymmetric carbon atom present in the side chain or to the tertiary chiral centres present in the main chain or both. 相似文献
100.
Buser M Frommhold L Gustafsson M Moraldi M Champagne MH Hunt KL 《The Journal of chemical physics》2004,121(6):2617-2621
Quantum line shape calculations of the rototranslational enhancement spectra of nitrogen-methane gaseous mixtures are reported. The calculations are based on a recent theoretical dipole function for interacting N(2) and CH(4) molecules, which accounts for the long-range induction mechanisms: multipolar inductions and dispersion force-induced dipoles. Multipolar induction alone was often found to approximate the actual dipole surfaces of pairs of interacting linear molecules reasonably well. However, in the case of the N(2)-CH(4) pair, the absorption spectra calculated with such a dipole function still show a substantial intensity defect at the high frequencies (>250 cm(-1)) when compared to existing measurements at temperatures from 126 to 297 K, much as was previously reported. 相似文献