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1.
New Trifluoromethylated Derivatives of Metal Nitride Clusterfullerenes: Sc3N@Ih‐C80(CF3)14 and Sc3N@D5h‐C80(CF3)16 下载免费PDF全文
Tao Wei Dr. Nadezhda B. Tamm Prof. Dr. Shangfeng Yang Prof. Dr. Sergey I. Troyanov 《化学:亚洲杂志》2014,9(9):2449-2452
Trifluoromethylated derivatives of Sc3N@Ih‐C80 and Sc3N@D5h‐C80 were synthesized by the reaction with CF3I at 440 °C. HPLC separation of the mixture of Sc3N@D5h‐C80(CF3)n derivatives resulted in isolation and X‐ray structure determination of Sc3N@D5h‐C80(CF3)16, which represents a precursor of the known Sc3N@D5h‐C80(CF3)18. Among the CF3 derivatives of Sc3N@Ih‐C80, two new isomers of Sc3N@Ih‐C80(CF3)14 ( Sc‐14‐VI and Sc‐14‐VII ) were isolated by HPLC, and their molecular structures were determined by X‐ray diffraction, thus enabling a comprehensive comparison of altogether seven isomers. Two types of addition patterns with different orientations of the Sc3N cluster relative to the Ih‐C80 fullerene cage were established. In particular, Sc‐14‐VII represents a direct precursor of the known Sc3N@Ih‐C80(CF3)16‐ II . All molecular structures exhibit an ordered position of a Sc3N cluster inside the fullerene C80 cage. 相似文献
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Julio R. Pinzón Claudia M. Cardona Dr. Maria Ángeles Herranz Dr. Marta E. Plonska‐Brzezinska Dr. Amit Palkar Andreas J. Athans Dr. Nazario Martín Prof. Dr. Antonio Rodríguez‐Fortea Dr. Josep M. Poblet Prof. Dr. Giovanni Bottari Dr. Tomás Torres Prof. Dr. S. Shankara Gayathri Dr. Dirk M. Guldi Prof. Dr. Luis Echegoyen Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(4):864-877
The first pyrrolidine and cyclopropane derivatives of the trimetallic nitride templated (TNT) endohedral metallofullerenes Ih‐Sc3N@C80 and Ih‐Y3N@C80 connected to an electron‐donor unit (i.e., tetrathiafulvalene, phthalocyanine or ferrocene) were successfully prepared by 1,3‐dipolar cycloaddition reactions of azomethine ylides and Bingel–Hirsch‐type reactions. Electrochemical studies confirmed the formation of the [6,6] regioisomers for the Y3N@C80‐based dyads and the [5,6] regioisomers in the case of Sc3N@C80‐based dyads. Similar to other TNT endohedral metallofullerene systems previously synthesized, irreversible reductive behavior was observed for the [6,6]‐Y3N@C80‐based dyads, whereas the [5,6]‐Sc3N@C80‐based dyads exhibited reversible reductive electrochemistry. Density functional calculations were also carried out on these dyads confirming the importance of these structures as electron transfer model systems. Furthermore, photophysical investigations on a ferrocenyl–Sc3N@C80‐fulleropyrrolidine dyad demonstrated the existence of a photoinduced electron‐transfer process that yields a radical ion pair with a lifetime three times longer than that obtained for the analogous C60 dyad. 相似文献
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Julio R. Pinzón Claudia M. Cardona Dr. Maria Ángeles Herranz Dr. Marta E. Plonska‐Brzezinska Dr. Amit Palkar Andreas J. Athans Dr. Nazario Martín Prof. Dr. Antonio Rodríguez‐Fortea Dr. Josep M. Poblet Prof. Dr. Giovanni Bottari Dr. Tomás Torres Prof. Dr. S. Shankara Gayathri Dr. Dirk M. Guldi Prof. Dr. Luis Echegoyen Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(4):807-807
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Juan Pablo Martínez Dr. Marc Garcia‐Borràs Dr. Sílvia Osuna Dr. Jordi Poater Prof. Dr. F. Matthias Bickelhaupt Prof. Dr. Miquel Solà 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):5953-5962
We quantum chemically explore the thermodynamics and kinetics of all 65 possible mechanistic pathways of the Bingel–Hirsch addition of dimethyl bromomalonate to the endohedral metallofullerene La@C2v‐C82 that result from the combination of 24 nonequivalent carbon atoms and 35 different bonds present in La@C2v‐C82 by using dispersion‐corrected DFT calculations. Experimentally, this reaction leads to four singly bonded derivatives and one fulleroid adduct. Of these five products, only the singly bonded derivative on C23 could be experimentally identified unambiguously. Our calculations show that La@C2v‐C82 is not particularly regioselective under Bingel–Hirsch conditions. From the obtained results, however, it is possible to make a tentative assignment of the products observed experimentally. We propose that the observed fulleroid adduct results from the attack at bond 19 and that the singly bonded derivatives correspond to the C2, C19, C21, and C23 initial attacks. However, other possibilities cannot be ruled out completely. 相似文献
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Dr. Sílvia Osuna Dr. Ramón Valencia Dr. Antonio Rodríguez‐Fortea Prof. Marcel Swart Prof. Miquel Solà Prof. Josep M. Poblet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(29):8944-8956
In this work a detailed investigation of the exohedral reactivity of the most important and abundant endohedral metallofullerene (EMF) is provided, that is, Sc3N@Ih‐C80 and its D5h counterpart Sc3N@D5h‐C80, and the (bio)chemically relevant lutetium‐ and gadolinium‐based M3N@Ih/D5h‐C80 EMFs (M=Sc, Lu, Gd). In particular, we analyze the thermodynamics and kinetics of the Diels–Alder cycloaddition of s‐cis‐1,3‐butadiene on all the different bonds of the Ih‐C80 and D5h‐C80 cages and their endohedral derivatives. First, we discuss the thermodynamic and kinetic aspects of the cycloaddition reaction on the hollow fullerenes and the two isomers of Sc3N@C80. Afterwards, the effect of the nature of the metal nitride is analyzed in detail. In general, our BP86/TZP//BP86/DZP calculations indicate that [5,6] bonds are more reactive than [6,6] bonds for the two isomers. The [5,6] bond D 5h ‐b , which is the most similar to the unique [5,6] bond type in the icosahedral cage, I h ‐a , is the most reactive bond in M3N@D5h‐C80 regardless of M. Sc3N@C80 and Lu3N@C80 give similar results; the regioselectivity is, however, significantly reduced for the larger and more electropositive M=Gd, as previously found in similar metallofullerenes. Calculations also show that the D5h isomer is more reactive from the kinetic point of view than the Ih one in all cases which is in good agreement with experiments. 相似文献
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《化学:亚洲杂志》2017,12(12):1391-1399
Photochemical carbosilylation of Sc3N@Ih ‐C80 with silirane 1 afforded two corresponding [5,6]‐adducts, 2 and 3 , and a [6,6]‐adduct, 4 . The structural and electronic properties of these products were characterized by means of spectroscopic, electrochemical, and theoretical methods. The structure of 2 was disclosed by means of single‐crystal X‐ray crystallographic analysis. Thermal isomerization of 3 to 2 was observed, whereas that of 2 to 3 proceeded less efficiently at 100 °C. Upon heating under the same conditions, adduct 4 underwent facile decomposition to afford Sc3N@Ih ‐C80, or isomerized into small amounts of 2 and 3 . The relative stabilities of 2 , 3 , and 4 were rationalized through the results of theoretical calculations. In contrast, adducts 2 , 3 , and 4 were stable under the photolytic conditions employed for carbosilylation. The photochemical functionalization of Sc3N@Ih ‐C80 represents a convenient synthetic method to obtain thermally labile fullerene‐based products. 相似文献
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Synthesis and Isolation of the Titanium–Scandium Endohedral Fullerenes—Sc2TiC@Ih‐C80, Sc2TiC@D5h‐C80 and Sc2TiC2@Ih‐C80: Metal Size Tuning of the TiIV/TiIII Redox Potentials 下载免费PDF全文
Katrin Junghans Dr. Kamran B. Ghiassi Nataliya A. Samoylova Qingming Deng Marco Rosenkranz Prof. Marilyn M. Olmstead Prof. Alan L. Balch Dr. Alexey A. Popov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(37):13098-13107
The formation of endohedral metallofullerenes (EMFs) in an electric arc is reported for the mixed‐metal Sc–Ti system utilizing methane as a reactive gas. Comparison of these results with those from the Sc/CH4 and Ti/CH4 systems as well as syntheses without methane revealed a strong mutual influence of all key components on the product distribution. Whereas a methane atmosphere alone suppresses the formation of empty cage fullerenes, the Ti/CH4 system forms mainly empty cage fullerenes. In contrast, the main fullerene products in the Sc/CH4 system are Sc4C2@C80 (the most abundant EMF from this synthesis), Sc3C2@C80, isomers of Sc2C2@C82, and the family Sc2C2 n (2 n=74, 76, 82, 86, 90, etc.), as well as Sc3CH@C80. The Sc–Ti/CH4 system produces the mixed‐metal Sc2TiC@C2 n (2 n=68, 78, 80) and Sc2TiC2@C2 n (2 n=80) clusterfullerene families. The molecular structures of the new, transition‐metal‐containing endohedral fullerenes, Sc2TiC@Ih‐C80, Sc2TiC@D5h‐C80, and Sc2TiC2@Ih‐C80, were characterized by NMR spectroscopy. The structure of Sc2TiC@Ih‐C80 was also determined by single‐crystal X‐ray diffraction, which demonstrated the presence of a short Ti=C double bond. Both Sc2TiC‐ and Sc2TiC2‐containing clusterfullerenes have Ti‐localized LUMOs. Encapsulation of the redox‐active Ti ion inside the fullerene cage enables analysis of the cluster–cage strain in the endohedral fullerenes through electrochemical measurements. 相似文献
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Ramón Valencia Antonio Rodríguez‐Fortea Dr. Anna Clotet Dr. Coen de Graaf Dr. Manuel N. Chaur Luis Echegoyen Prof. Dr. Josep M. Poblet Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(41):10997-11009
An extensive study of the redox properties of metal nitride endohedral fullerenes (MNEFs) based on DFT computational calculations has been performed. The electronic structure of the singly oxidized and reduced MNEFs has been thoroughly analyzed and the first anodic and cathodic potentials, as well as the electrochemical gaps, have been predicted for a large number of M3N@C2n systems (M=Sc, Y, La, and Gd; 2n=80, 84, 88, 92, and 96). In particular, calculations that include thermal and entropic effects correctly predict the different anodic behavior of the two isomers (Ih and D5h) of Sc3N@C80, which is the basis for their electrochemical separation. Important differences were found in the electronic structure of reduced M3N@C80 when M=Sc or when M is a more electropositive metal, such as Y or Gd. Moreover, the changes in the electrochemical gaps within the Gd3N@C2n series (2n=80, 84, and 88) have been rationalized and the use of Y‐based computational models to study the Gd‐based systems has been justified. The redox properties of the largest MNEFs characterized so far, La3N@C2n (2n=92 and 96), were also correctly predicted. Finally, the quality of these predictions and their usefulness in distinguishing the carbon cages for MNEFs with unknown structures is discussed. 相似文献
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Pradip Pachfule Vishal M. Dhavale Sharath Kandambeth Dr. Sreekumar Kurungot Dr. Rahul Banerjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(3):974-980
Porous nitrogen‐rich carbon (POF‐C‐1000) that was synthesized by using a porous organic framework (POF) as a self‐sacrificing host template in a nanocasting process possessed a high degree of graphitization in an ordered structural arrangement with large domains and well‐ordered arrays of carbon sheets. POF‐C‐1000 exhibits favorable electrocatalytic activity for the oxygen‐reduction reaction (ORR) with a clear positive shift of about 40 mV in the onset potential compared to that of a traditional, commercially available Pt/C catalyst. In addition, irrespective of its moderate surface area (785 m2 g?1), POF‐C‐1000 showed a reasonable H2 adsorption of 1.6 wt % (77 K) and a CO2 uptake of 3.5 mmol g?1 (273 K). 相似文献
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Taku Hasobe Dr. Shunichi Fukuzumi Prof. Shigeki Hattori Prashant V. Kamat Prof. 《化学:亚洲杂志》2007,2(2):265-272
Shape‐ and functionality‐controlled organization of porphyrin derivatives–C60 supramolecular assemblies using TiO2 nanotubes and nanoparticles has been achieved for the development of photochemical solar cells. The differences in the efficiency of light‐energy conversion of these solar cells are explained on the basis of the geometrical orientation of the porphyrins with respect to the TiO2 surface and the supramolecular complex formed with C60. The maximum photon‐conversion efficiency (IPCE) of 60 % obtained with TiO2 nanotube architecture is higher than the value obtained with nanoparticle architecture. The results presented in this study show the importance of substrate morphology in promoting electron transport within the mesoscopic semiconductor film. 相似文献
12.
Essential Factors for Control of the Equilibrium in the Reversible Rearrangement of M3N@Ih‐C80 Fulleropyrrolidines: Exohedral Functional Groups versus Endohedral Metal Clusters 下载免费PDF全文
Safwan Aroua Marc Garcia‐Borràs Dr. Sílvia Osuna Dr. Yoko Yamakoshi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):14032-14039
The effects of exohedral moieties and endohedral metal clusters on the isomerization of M3N@Ih‐C80 products from the Prato reaction through [1,5]‐sigmatropic rearrangement were systematically investigated by using three types of fulleropyrrolidine derivatives and four different endohedral metal clusters. As a result, all types of derivatives provided the same ratios of the isomers for a given trimetallic nitride template (TNT) as the thermodynamic products, thus indicating that the size of the endohedral metal clusters inside C80 was the single essential factor in determining the equilibrium between the [6,6]‐isomer (kinetic product) and the [5,6]‐isomer. In all the derivatives, the [6,6]‐ and [5,6]‐Prato adducts with larger metal clusters, such as Y3N and Gd3N, were equally stable, which is in good agreement with DFT calculations. The reaction rate of the rearrangement was dependent on both the substituent of exohedral functional groups and the endohedral metal‐cluster size. Further DFT calculations and 13C NMR spectroscopic studies were employed to rationalize the equilibrium in the rearrangement between the [6,6]‐ and [5,6]‐fulleropyrrolidines. 相似文献
13.
New Conjugated Molecules with Two and Three Dithienyldiketopyrrolopyrrole (DPP) Moieties Substituted at meta Positions of Benzene toward p‐ and n‐Type Organic Photovoltaic Materials 下载免费PDF全文
Chenmin Yu Dr. Chang He Yang Yang Zhengxu Cai Hewei Luo Wenqiang Li Dr. Qian Peng Dr. Guanxin Zhang Dr. Zitong Liu Prof. Deqing Zhang 《化学:亚洲杂志》2014,9(6):1570-1578
Two conjugated molecules, TADPP3 and TADPP2‐TT , are reported, in which three and two dithienyldiketopyrrolopyrrole (DPP) moieties, respectively, are substituted at the meta positions of benzene. Based on cyclic voltammetry and absorption data, TADPP3 and TADPP2‐TT possess similar HOMO and LUMO energies of about ?5.2 and ?3.4 eV, respectively. Thin films of TADPP3 and TADPP2‐TT exhibit p‐type semiconducting behavior with hole mobilities of 2.36×10?3 and 3.76×10?4 cm2 V?1 s?1 after thermal annealing. Molecules TADPP3 and TADPP2‐TT were utilized as p‐type photovoltaic materials to fabricate organic solar cells after blending with phenyl C71 butyric acid methyl ester ( PC71BM ) and phenyl C61 butyric acid methyl ester ( PC61BM ). The relatively low JSC and fill factor values can be attributed to poor film morphologies based on AFM and XRD studies. A solar cell with a thin film of TADPP3 with PC71BM in a weight ratio of 1:2 exhibits a high open‐circuit voltage (VOC) of 0.99 V and a power conversion efficiency (PCE) of 2.47 %. Interestingly, TADPP3 can also be employed as an n‐type photovoltaic material. The blended thin film of TADPP3 with P3HT in a weight ratio of 1:2 gave a high VOC of 1.11 V and a PCE of 1.08 % after thermal annealing. 相似文献
14.
Marc Garcia‐Borràs Dr. Sílvia Osuna Dr. Josep M. Luis Prof. Marcel Swart Prof. Miquel Solà 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(23):7141-7154
The chemical functionalization of endohedral (metallo)fullerenes has become a main focus of research in the last few years. It has been found that the reactivity of endohedral (metallo)fullerenes may be quite different from that of the empty fullerenes. Encapsulated species have an enormous influence on the thermodynamics, kinetics, and regiochemistry of the exohedral addition reactions undergone by these species. A detailed understanding of the changes in chemical reactivity due to incarceration of atoms or clusters of atoms is essential to assist the synthesis of new functionalized endohedral fullerenes with specific properties. Herein, we report the study of the Diels–Alder cycloaddition between 1,3‐butadiene and all nonequivalent bonds of the Ti2C2@D3h‐C78 metallic carbide endohedral metallofullerene (EMF) at the BP86/TZP//BP86/DZP level of theory. The results obtained are compared with those found by some of us at the same level of theory for the D3h‐C78 free cage and the M3N@D3h‐C78 (M=Sc and Y) metallic nitride EMFs. It is found that the free cage is more reactive than the Ti2C2@D3h‐C78 EMF and this, in turn, has a higher reactivity than M3N@D3h‐C78. The results indicate that, for Ti2C2@D3h‐C78, the corannulene‐type [5, 6] bonds c and f , and the type B [6, 6] bond 3 are those thermodynamically and kinetically preferred. In contrast, the D3h‐C78 free cage has a preference for addition to the [6, 6] 1 and 6 bonds and the [5, 6] b bond, whereas M3N@D3h‐C78 favors additions to the [6, 6] 6 (M=Sc) and [5, 6] d (M=Y) bonds. The reasons for the regioselectivity found in Ti2C2@D3h‐C78 are discussed. 相似文献
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Yang S Zalibera M Rapta P Dunsch L 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(30):7848-7855
The electrochemistry of three new clusterfullerenes Dy3N@C2n (2n=78, 80), namely two isomers of Dy3N@C80 (I and II) as well as Dy3N@C78 (II), have been studied systematically including their redox-reaction mechanism. The cyclic voltammogram of Dy3N@C80 (I) (Ih) exhibits two electrochemically irreversible but chemically reversible reduction steps and one reversible oxidation step. Such a redox pattern is quite different from that of Sc3N@C80 (I), and this can be understood by considering the difference in the charge transfer from the encaged cluster to the cage. A double-square reaction scheme is proposed to explain the observed redox-reaction behavior, which involves the charge-induced reversible rearrangement of the Dy3N@C80 (I) monoanion. The first oxidation potential of Dy3N@C80 (II) (D5h) has a negative shift of 290 mV relative to that of Dy3N@C80 (I) (Ih), indicating that lowering the molecular symmetry of the clusterfullerene cage results in a prominent increase in the electron-donating property. The first and second reduction potentials of Dy3N@C78 (II) are negatively shifted relative to those of Dy3N@C80 (I, II), pointing to the former's lowered electron-accepting ability. The significant difference in the electrochemical energy gaps of Dy3N@C80 (I), Dy3N@C80 (II), and Dy3N@C78 (II) is consistent with the difference in their optical energy gaps. 相似文献
19.
Approach to High Open‐Circuit Voltage in Organic Solar Cells Utilizing a Structural Change of the Oxazolino‐C70 Derivative 下载免费PDF全文
Shu‐Hui Li Dr. Zong‐Jun Li Dr. Takafumi Nakagawa Dr. James W. Ryan Prof. Dr. Yutaka Matsuo Prof. Dr. Xiang Gao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):1894-1899
Reactions of 2,5‐Bn2C70 (Bn=CH2Ph) with hydroxide and ArCN (Ar=Ph, m‐ClPh) followed by quenching with I2 and BnBr afforded dibenzylated and tetrabenzylated oxazolino[70]fullerenes, respectively. The latter has a novel structural configuration, in which the addends are positioned from the polar to the transequatorial region. A key structural feature of this compound is that the oxygen atom of the oxazoline ring is bound to the equatorial belt region of C70, giving structural change in its reduced state. This enables stabilization of the reduced state, suppressing charge recombination dynamics in organic solar cells to give a high open‐circuit voltage (0.85, 0.93, and 1.11 V in devices using P3HT, PTB7, and DPP(TBFu)2, respectively). 相似文献
20.
Lisa M. Kozycz Dong Gao Andrew J. Tilley Dwight S. Seferos 《Journal of polymer science. Part A, Polymer chemistry》2014,52(23):3337-3345
A series of one donor–two acceptor (D–A1)‐(D–A2) random terpolymers containing a 2,7‐carbazole donor and varying compositions of perylene diimide (PDI) and naphthalene diimide (NDI) acceptors was synthesized via Suzuki coupling polymerization. The optical properties of the terpolymers are weighted sums of the constituent parent copolymers and all show strong absorption over the 400 to 700 nm range with optical bandgaps ranging from 1.77 to 1.87 eV, depending on acceptor composition. The copolymers were tested as acceptor materials in bulk heterojunction all‐polymer solar cells using poly[(4,8‐bis‐(2‐ethylhexyloxy)‐benzo[1,2‐b;4,5‐b′]dithiophene)‐2,6‐diyl‐alt‐(4‐(2‐ethylhexanoyl)‐thieno[3,4‐b]thiophene)‐2,6‐diyl] (PBDTTT‐C) as the donor material. In contrast to the optoelectronic properties, the measured device parameters are not composition dependent, and rather depend solely on the presence of the NDI unit, where the devices containing any amount of NDI perform half as well as those using the parent polymer containing only carbazole and PDI. Overall this is the first example of a one donor–two acceptor random terpolymer system containing perylene diimide (PDI) and naphthalene diimide (NDI) acceptor units, and demonstrates a facile method of tuning polymer optoelectronic properties while minimizing the need for complicated synthetic and purification steps. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3337–3345 相似文献