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991.
Highly Contorted 1,2,5‐Thiadiazole‐Fused Aromatics for Solution‐Processed Field‐Effect Transistors: Synthesis and Properties 下载免费PDF全文
Xin Shi Shuli Liu Chunming Liu Yueming Hu Saihua Shi Dr. Nina Fu Dr. Baomin Zhao Prof. Dr. Zhaohui Wang Prof. Dr. Wei Huang 《化学:亚洲杂志》2016,11(15):2188-2200
A straightforward strategy has been used to construct 1,2,5‐thiadiazole‐fused 12‐ring π systems through twofold Stille coupling and subsequent cyclodehydrogenation by utilizing the building blocks of naphthodithiophene and 5,6‐substituted benzo[b]‐2,1,3‐thiadidazole. Molecules 1 a and 1 b , which exhibit highly contorted π surfaces, show a butterfly‐shaped conformation according to DFT calculations. Within the molecules, a plane‐to‐plane angle of 44.8° was found. UV/Vis absorption, thermogravimetric analysis, differential scanning calorimetry, and cyclic voltammetry (CV) were used to study their physical properties. Strong intermolecular interactions of the nonplanar molecules were also observed by concentration‐dependent 1H NMR spectroscopy measurements and thin‐film XRD characterization. The low‐lying LUMO and high‐lying HOMO levels of the molecules are ?3.73 and ?5.48 eV, respectively, as estimated from CV measurements; this indicates their potential as semiconducting materials for solution‐processed organic field‐effect transistors (OFETS). A field‐effect hole mobility of up to 0.035 cm2 V?1 s?1, a threshold voltage of 6.98 V, and a current on/off ratio of 8.65×105 in air for 1 a have been demonstrated with the top‐contact bottom‐gate field‐effect transistor device structures; this represents an important step toward the solution‐processed OFET application of contorted aromatics. 相似文献
992.
6‐TIPS‐β‐Cyclodextrin‐Modified Fe3O4 for Facile Enantioseparation of 1‐(1‐Naphthyl)ethylamine 下载免费PDF全文
Lu Wang Xiang‐Yong Liang Prof. Dr. Li‐Sheng Ding Prof. Dr. Sheng Zhang Prof. Dr. Bang‐Jing Li 《化学:亚洲杂志》2016,11(24):3513-3519
A new type of chiral magnetic nanoparticle was prepared from covalently linked magnetic nanoparticles (Fe3O4) and heptakis‐(6‐O‐triisopropylsilyl)‐β‐cyclodextrin (6‐TIPS‐β‐CD). The resulting selectors (TIPS‐β‐CD‐MNPs) combined the good magnetic properties Fe3O4 and efficient chiral recognition ability of 6‐TIPS‐β‐CD. The enantioselectivity of TIPS‐β‐CD‐MNPs towards 1‐(1‐naphthyl)ethylamine was six times higher than that of the parent β‐CD modified Fe3O4 particles. 相似文献
993.
Prof. Dr. Tetsuo Okujima Dr. John Mack Dr. Jun Nakamura Gugu Kubheka Prof. Dr. Tebello Nyokong Dr. Hua Zhu Naoki Komobuchi Prof. Dr. Noboru Ono Prof. Dr. Hiroko Yamada Prof. Dr. Hidemitsu Uno Prof. Dr. Nagao Kobayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(41):14730-14738
A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro‐Diels–Alder reaction of bicyclo[2.2.2]octadiene‐fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time‐dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier π‐molecular orbitals. 相似文献
994.
995.
Jianping Wang Yoonjung Jang Jayshree K. Khedkar Jin Young Koo Yonghwi Kim Chang Jun Lee Young Min Rhee Kimoon Kim 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(44):15791-15799
Cucurbit[7]uril (CB[7]) is known to bind strongly to hydrophilic amino saccharide guests with exceptional α‐anomer selectivities under aqueous conditions. Single‐crystal X‐ray crystallography and computational methods were used to elucidate the reason behind this interesting phenomenon. The crystal structures of protonated galactosamine (GalN) and glucosamine (GluN) complexes confirm the inclusion of α anomers inside CB[7] and disclose the details of the host–guest binding. Whereas computed gas‐phase structures agree with these crystal structures, gas‐phase binding free energies show preferences for the β‐anomer complexes over their α counterparts, in striking contrast to the experimental results under aqueous conditions. However, when the solvation effect is considered, the binding structures drastically change and the preference for the α anomers is recovered. The α anomers also tend to bind more tightly and leave less space in the CB[7] cavity toward inclusion of only one water molecule, whereas loosely bound β anomers leave more space toward accommodating two water molecules, with markedly different hydrogen‐bonding natures. Surprisingly, entropy seems to contribute significantly to both anomeric discrimination and binding. This suggests that of all the driving factors for the strong complexation of the hydrophilic amino saccharide guests, water mediation plays a crucial role in the anomer discrimination. 相似文献
996.
Dr. Aron J. Huckaba Dr. Aswani Yella Dr. Louis E. McNamara April E. Steen J. Scott Murphy Casey A. Carpenter George D. Puneky Prof. Nathan I. Hammer Prof. Mohammad Khaja Nazeeruddin Prof. Michael Grätzel Prof. Jared H. Delcamp 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15536-15542
Desirable components for dye‐sensitzed solar cell (DSC) sensitizers and fluorescent imaging dyes include strong donating building blocks coupled with well‐balanced acceptor functionalities for absorption beyond the visible range. We have evaluated the effects of increasing acceptor strengths and incorporation of dye morphology controlling groups on molar absorptivity and absorption breadth with indolizine donor‐based dyes. Indolizine‐based D –A and D –π–A sensitizers incorporating bis‐rhodanine, tricyanofuran (TCF), and cyanoacrylic acid functionalities were analyzed for performance in DSC devices. The TCF derivatives were also evaluated as near‐infrared (NIR)‐emissive materials with the AH25 emissions extending past 1000 nm. 相似文献
997.
Paul Kautny Dorian Bader Dr. Berthold Stöger Prof. Dr. Georg A. Reider Prof. Dr. Johannes Fröhlich Dr. Daniel Lumpi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(52):18887-18898
To shed light on intramolecular charge‐transfer phenomena in 1,2,3‐triazole‐linked materials, a series of 1,2,3‐triazole‐linked push–pull chromophores were prepared and studied experimentally and computationally. Investigated modifications include variation of donor and/or acceptor strength and linker moiety as well as regioisomers. Photophysical characterization of intramolecular charge‐transfer features revealed ambipolar behavior of the triazole linker, depending on the substitution position. Furthermore, non‐centrosymmetric materials were subjected to second‐harmonic generation measurements, which revealed the high nonlinear optical activity of this class of materials. 相似文献
998.
Dr. Shinnosuke Horiuchi Hirotaka Tanaka Prof. Dr. Eri Sakuda Prof. Dr. Yasuhiro Arikawa Prof. Dr. Keisuke Umakoshi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17533-17537
Encapsulation and luminescence studies of [Ir(ppy)2(bpy)]Cl (ppy=2‐phenylpyridinate, bpy=2,2′‐bipyridine) within a hexameric resorcinarene capsule are reported. One IrIII complex cation was encapsulated within the capsule, as demonstrated by NMR and dynamic light scattering (DLS) studies. The emission color of the IrIII complex was drastically changed from orange to yellow by encapsulation, in contrast with the lack of significant changes in the absorption spectrum. The hexameric capsule effectively hampers the non‐radiative pathway to increase both the luminescence quantum yield and the exited state lifetime. The luminescent properties of the encapsulated IrIII complex depend on the ratio of IrIII complex to the resorcinarene monomer as well as the concentration of resorcinarene monomer owing to the reversible process of self‐assembly of the hexameric capsule. Quenching experiments revealed that the IrIII complex in the capsule was effectively separated from quenchers. 相似文献
999.
Barbara Berkes Kristóf Ozsváth Laura Molnár Tamás Gáti Tamás Holczbauer György Kardos Tibor Soós 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(50):18101-18106
We report an expedient approach to highly functionalized cis‐ and trans‐decalines that could function as key structural subunits toward the synthesis of various classes of terpenoids. Key to the strategy is an organocatalyzed Robinson annulation reaction of the Nazarov reagent that affords chiral enone building blocks with high enantioselectivities. The quaternary carbon stereogenic center can direct the subsequent reactions and allow the rapid and diastereoconvergent assembly of complex decalines with contiguous stereocenters. 相似文献
1000.