bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solution‐Processible Red Iridium Dendrimers based on Oligocarbazole Host Dendrons: Synthesis, Properties, and their Applications in Organic Light‐Emitting Diodes
Authors: Ding Junqiao , Lü Jianhong , Cheng Yanxiang , Xie Zhiyuan , Wang Lixiang , Jing Xiabin , Wang Fosong 
Published: September 2008

AbstractA series of novel red‐emitting iridium dendrimers functionalized with oligocarbazole host dendrons up to the third generation (red‐G3) have been synthesized by a convergent method, and their photophysical, electrochemical, and electroluminescent properties have been investigated. In addition to controlling the intermolecular interactions, oligocarbazole‐based dendrons could also participate in the electrochemical and charge‐transporting process. As a result, highly efficient electrophosphorescent devices can be fabricated by spin‐coating from chlorobenzene solution in different device configurations. The maximum external quantum efficiency (EQE) based on the non‐doped device configuration increases monotonically with increasing dendron generation. An EQE as high as 6.3% was obtained as for the third generation dendrimer red‐G3, which is about 30 times higher than that of the prototype red‐G0. Further optimization of the device configuration gave an EQE of 11.8% (13.0 cd A−1, 7.2 lm W−1) at 100 cd m−2 with CIE coordinates of (0.65, 0.35). The state‐of‐the‐art performance indicated the potential of these oligocarbazole‐based red iridium dendrimers as solution processible emissive materials for organic light‐emitting diode applications.
Platinum Lead Nanostructures: Formation, Phase Behavior, and Electrocatalytic Properties
Authors: Yang Shengchun , Peng Zhenmeng , Yang Hong 
Published: September 2008

AbstractThis paper describes the synthesis and crystal phase behavior of platinum lead nanorods. Both face‐centered cubic (fcc) Pt100−xPbx (x < 50) and hexagonally close‐packed (hcp) Pt50Pb50 nanostructures are synthesized at mild reaction temperatures (180–200 °C). The crystal phase and composition of these PtPb nanorods can be controlled by changing the reaction time and temperature. A mechanism for the formation of either kinetically or thermodynamically stable PtPb nanorods is discussed. The approach developed for controlling crystal phases at fairly low temperatures can be important for the design of alloy or intermetallic nanostructures for a broader range of applications.
Bulk Synthesis and Surface Patterning of Nanoporous Metals and Alloys from Supraspherical Nanoparticle Aggregates
Authors: Klajn Rafal , Gray Timothy P. , Wesson Paul J. , Myers Benjamin D. , Dravid Vinayak P. , Smoukov Stoyan K. , Grzybowski Bartosz A. 
Published: September 2008

AbstractSupraspheres (SS) composed of hundreds to thousands of metal nanoparticles (NPs) and crosslinked by dithiol linkers are assembled into larger structures, which are subsequently converted into nanoporous metals (NMs). Conversion is achieved by heating which removes organic molecules stabilizing the NPs and allows for NP fusion. Heating of SS solutions leads to NMs of overall macroscopic dimensions; localized radiation using collimated electron beam is used to prepare metallized surface micropatterns. Depending on the composition of supraspherical precursors, nanoporous materials composed of up to three metals can be obtained. Strategies for controlling pore size and nanoscale surface roughness of these materials are discussed.
Traversing the Metal‐Insulator Transition in a Zintl Phase: Rational Enhancement of Thermoelectric Efficiency in Yb14Mn1−xAlxSb11
Authors: Toberer Eric S. , Cox Catherine A. , Brown Shawna R. , Ikeda Teruyuki , May Andrew F. , Kauzlarich Susan M. , Snyder G. Jeffrey 
Published: September 2008

AbstractFor high temperature thermoelectric applications, Yb14MnSb11 has a maximum thermoelectric figure of merit (zT) of ∼1.0 at 1273 K. Such a high zT is found despite a carrier concentration that is higher than typical thermoelectric materials. Here, we reduce the carrier concentration with the discovery of a continuous transition between metallic Yb14MnSb11 and semiconducting Yb14AlSb11. Yb14Mn1‐xAlxSb11 forms a solid solution where the free carrier concentration gradually changes as expected from the Zintl valence formalism. Throughout this transition the electronic properties are found to obey a rigid band model with a band gap of 0.5 eV and an effective mass of 3 me. As the carrier concentration decreases, an increase in the Seebeck coefficient is observed at the expense of an increased electrical resistivity. At the optimum carrier concentration, a maximum zT of 1.3 at 1223 K is obtained, which is more than twice that of the state‐of‐the‐art Si0.8Ge0.2 flown by NASA.
Luminescent Tags on Fullerenes: Eu3+ Complexes with Pendant Fullerenes
Authors: Fuchsbauer Anita , Troshina Olesya A. , Troshin Pavel A. , Koeppe Robert , Lyubovskaya Rimma N. , Sariciftci Niyazi Serdar 
Published: September 2008

AbstractNovel fullerene‐containing Eu (III) complexes are obtained by mixing a fullerene derivative bearing chelating pyridinyl groups with an Eu (III) complex possessing three coordinated 4,4,4,‐trifluoro‐1‐(2‐naphtyl)‐1,3‐butanedione residues and two water molecules. One of the complexes designed is formed in water using a water‐soluble fullerene derivative as a precursor material. We investigate the photophysical properties of this new type of highly soluble self‐assembled fullerene‐derivative Eu3+ coordination compounds. A strong emission line of the Eu3+ 4f–4f transition is recorded under excitation with UV irradiation. The behaviour of the complexes in organic matrices and water is studied as the first steps towards luminescence tagged fullerene derivatives for use in biomedicine and optoelectronics.
Light‐Emission Performance of Silicon Nanocrystals Deduced from Single Quantum Dot Spectroscopy
Authors: Valenta Jan , Fucikova Anna , Vácha František , Adamec František , Humpolíčková Jana , Hof Martin , Pelant Ivan , Kůsová Kateřina , Dohnalová Kateřina , Linnros Jan 
Published: September 2008

AbstractSpectra of individual silicon nanocrystals within porous Si grains are studied by the wide‐field imaging microspectroscopy and their ON–OFF blinking is detected by the confocal single‐photon‐counting microscopy. Observed spectral and blinking properties comprise all features reported before in differently prepared single Si nanocrystals (SiNCs). Former apparently contradictory results are shown to be due to different experimental conditions. When the effect of dark periods (OFF switching) is removed the common ultimate photoluminescence properties of SiO2 passivated SiNCs are found, namely the quantum efficiency (QE) of about 10–20% up to the pumping rate corresponding to one exciton average excitation per quantum dot. At higher pump rates the QE is slowly decreasing as the 0.7th power of excitation. This is most likely due to Auger recombination which, however, seems to be weakened compared with measurements of nanocrystal assemblies. We conclude that SiNCs may be pumped above one exciton occupancy to yield a higher light emission, being advantageous for applications.
Tailor‐made Polymeric Membranes based on Segmented Block Copolymers for CO2 Separation
Authors: Car Anja , Stropnik Chrtomir , Yave Wilfredo , Peinemann Klaus‐Viktor 
Published: September 2008

AbstractThis paper reports the design of a tailor made polymeric membrane by using poly(ethylene oxide)–poly(butylene terephthalate) (PEO‐PBT) multi‐block copolymers. Their properties are controlled by the fraction of the PEO phase and its molecular weight. To explain the effect of structural changes in copolymer membranes, transport properties of four gases (CO2, H2, N2, and CH4) are discussed. After characterization, the two best copolymers are selected in order to prepare tailor made blends by adding poly(ethylene glycol) (PEG). The best selected copolymer that contained 55 wt. % of 4000 g mol−1 PEO produced a blend with high CO2 permeability (∼190 barrer), which is twice the permeability of the pure copolymer. At the same time, an enhancement of CO2/H2 selectivity is observed (∼13). These results suggest that the morphology of PEO‐PBT can be well controlled by the addition of low‐molecular‐weight PEG, and consequently the gas transport properties can be tuned.
Effect of Oligothienyl Chain Length on Tuning the Solar Cell Performance in Fluorene‐Based Polyplatinynes
Authors: Liu Li , Ho Cheuk‐Lam , Wong Wai‐Yeung , Cheung Kai‐Yin , Fung Man‐Kin , Lam Wai‐Ting , Djurišić Aleksandra B. , Chan Wai‐Kin 
Published: September 2008

AbstractA series of solution‐processable and strongly visible‐light absorbing polyplatinynes containing oligothienyl–fluorene ring hybrids were synthesized and characterized. These rigid‐rod organometallic materials are soluble in polar organic solvents and show intense absorptions in the visible spectral region, rendering them excellent candidates for bulk heterojunction polymer solar cells. The photovoltaic behavior depends significantly on the number of thienyl rings along the polymer chain, and some of these polymer solar cells show high power conversion efficiencies (PCEs) of up to 2.9% and a peak external quantum efficiency to 83% under AM1.5 simulated solar illumination. The effect of oligothienyl chain length on improving the polymer solar cell efficiency and on their optical and charge transport properties is elucidated in detail. At the same blend ratio of 1:5, the light‐harvesting capability and PCE increase markedly with increasing number of thienyl rings. The power dependencies of the solar cell parameters (including the short‐circuit current density, open‐circuit voltage, fill‐factor, and PCE) were also examined. The present work opens up an attractive avenue to developing conjugated metallopolymers with broad and strong solar energy absorptions and tunable solar cell efficiency and supports the potential of metalated conjugated polymers for efficient power generation.
Perfluorooctyl Bromide Polymeric Capsules as Dual Contrast Agents for Ultrasonography and Magnetic Resonance Imaging
Authors: Pisani Emilia , Tsapis Nicolas , Galaz Belfor , Santin Mathieu , Berti Romain , Taulier Nicolas , Kurtisovski Erol , Lucidarme Olivier , Ourevitch Michèle , Doan Bich Thuy , Beloeil Jean Claude , Gillet Brigitte , Urbach Wladimir , Bridal S. Lori , Fattal Elias 
Published: September 2008

AbstractPolymeric capsules with a thick shell made of biodegradable and biocompatible polymer and a liquid core of perfluorooctyl bromide (PFOB) were evaluated for stability as well as for ultrasound and magnetic resonance imaging (MRI) contrast enhancement. The method of preparation allows the mean capsule diameter to be regulated between 70 nm and 25 µm and the capsule thickness‐to‐radius ratio from 0.25 to 0.54. Capsule diameter remains stable at 37 °C in phosphate buffer for at least 4 and 6 h for nanocapsules and microcapsules, respectively. The in vitro ultrasound signal‐to‐noise ratio (SNR) was measured from 40 to 60 MHz for 6 µm and 150 nm capsules: the SNR increases with capsule concentration up to 20–25 mg mL−1, and then reaches a plateau that depends on capsule diameter (13.5 ± 1.5 dB for 6 µm and 6 ± 2 dB for the 150 nm capsules). The ultrasound SNR is stable for up to 20 min for microcapsules and for several hours for nanocapsules. For nanocapsules, the thinner the shell, the larger the SNR and the more compressible the capsules. Nanocapsule suspensions imaged in vitro with a commercial ultrasound imaging system (normal and tissue harmonic imaging modes, 7–14 MHz probe) were detected down to concentrations of 12.5 mg mL−1. Injections of nanocapsules (200 µg ml−1) in mice in vivo reveal that the initial bolus passage presents significant ultrasound enhancement of the blood pool during hepatic imaging (7–14 MHz probe, tissue harmonic imaging mode). 19F‐MRI images were obtained in vitro at 9.4T using spin‐echo and gradient echo sequences and allow detecting nanocapsules in suspension (50 mg mL−1). In conclusion, these results show initial feasibility for development of these capsules toward a dual‐modality contrast agent.
‘Mechanical Engineering’ of Elastomeric Proteins: Toward Designing New Protein Building Blocks for Biomaterials
Authors: Li Hongbin 
Published: September 2008

AbstractElastomeric proteins are subject to stretching force under biological settings and play important roles in regulating the mechanical properties of a wide range of biological machinery. Elastomeric proteins also underlie the superb mechanical properties of many protein‐based biomaterials. The developments of single molecule force spectroscopy have enabled the direct characterization of the mechanical properties of elastomeric proteins at the single molecule level and led to the new burgeoning field of research: single protein mechanics and engineering. Combined single molecule atomic force microscopy and protein engineering efforts are well under way to understand molecular determinants for the mechanical stability of elastomeric proteins and to develop methodologies to tune the mechanical properties of proteins in a rational and systematic fashion, which will lead to the ‘mechanical engineering’ of elastomeric proteins. Here the current status of these experimental efforts is discussed and the successes and challenges in constructing novel proteins with tailored nanomechanical proteins highlighted. The prospect of employing such engineered artificial elastomeric proteins as building blocks for the construction of biomaterials for applications ranging from material sciences to biomedical engineering are also discussed.magnified image
Syntheses, characterization and anti‐microbial activities of palladium(II) and palladium(IV) complexes of 3,10‐C‐meso‐Me8[14]diene (L1) and its reduced isomeric anes (LA, LB and LC). Crystal and molecular structure of [PdL1][Pd(SCN)4]
Authors: Roy Tapashi G. , Hazari Saroj K. S. , Barua Kanak K. , Kim Dong Il , Park Yu Chul , Tiekink Edward R.T. 
Published: September 2008

AbstractThe reactions of 3,10‐C‐meso‐3,5,7,7,10,12,14,14‐octamethyl‐1,4,8,11‐tetraazacyclotetradecadiene, L1, and two isomers (LB and LC, differing in the orientation of methyl groups on the chiral carbon atoms) of its reduced form with PdCl2 and K2[Pd(SCN)4], produce square‐planar tetrachloro‐ and tetrathiocyano‐palladium(II) complexes of general formulae [PdL′][PdCl4] and [PdL′][Pd(SCN)4] (L′ = L1, LB and LC), respectively. By contrast, the third ane isomer, LA, upon reaction with the same reagents, PdCl2 and K2[Pd(SCN)4], formed octahedral tetrachloro‐ and tetrathiocyanato‐palladium(IV) complexes [PdLACl2]Cl2 and [PdLA(SCN)2](SCN)2, respectively. The [PdL′][PdCl4] and [PdLACl2]Cl2 complexes undergo substitution reactions with KSCN to form square‐planar and octahedral tetrathiocyanato complexes [PdL′][Pd(SCN)4] and [PdLA(SCN)2](SCN)2, respectively. All complexes have been characterized on the basis of analytical, spectroscopic, conductometric and magnetochemical data. The anti‐fungal and anti‐bacterial activities of these complexes have been studied against some phytopathogenic fungi and bacteria. The crystal structure of [PdL1][Pd(SCN)4] has been confirmed by X‐ray crystallography and shows with square‐planar PdN4 and PdS4 geometries [monoclinic, space group C2/c, a = 17.884(3) Å, b = 14.734(2) Å, c = 11.4313(18) Å, β = 104.054(5)° ]. Copyright © 2008 John Wiley & Sons, Ltd.
On multiple‐class prediction of issuer credit ratings
Authors: Hwang Ruey‐Ching , Cheng K. F. , Lee Cheng‐Few 
Published: September 2008

AbstractFor multiple‐class prediction, a frequently used approach is based on ordered probit model. We show that this approach is not optimal in the sense that it is not designed to minimize the error rate of the prediction. Based upon the works by Altman (J. Finance1968;23:589–609), Ohlson (J. Accounting Res.1980;18:109–131), and Begleyet al.(Rev. Accounting Stud.1996;1:267–284) on two‐class prediction, we propose a modified ordered probit model. The modified approach depends on an optimal cutoff value and can be easily applied in applications. An empirical study is used to demonstrate that the prediction accuracy rate of the modified classifier is better than that obtained from usual ordered probit model. In addition, we also show that not only the usual accounting variables are useful for predicting issuer credit ratings, market‐driven variables and industry effects are also important determinants. Copyright © 2008 John Wiley & Sons, Ltd.
ChemInform Abstract: Crystal Structures of Ag2ZrF6×8NH3 and Ag2HfF6×8NH3 and Their Synthesis by the “Reactive Fluoride Route” in Liquid Ammonia.
Authors: Meng Weizhe , Kraus Florian 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Syntheses of Metal Nitrides, Metal Carbides and Rare‐Earth Metal Dioxymonocarbodiimides from Metal Oxides and Dicyandiamide.
Authors: Lei M. , Zhao H. Z. , Yang H. , Song B. , Cao L. Z. , Li P. G. , Tang W. H. 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: β‐ and γ‐Disubstituted Olefins: Substrates for Copper‐Catalyzed Asymmetric Allylic Substitution.
Authors: Falciola Caroline A. , Tissot‐Croset Karine , Reyneri Hugo , Alexakis Alexandre 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: An Interesting Cyclization of N‐Methyl‐3‐phenyl‐N‐(2‐(Z)‐phenylethenyl)‐cis‐oxiranecarboxamide.
Authors: Ma Nianchun , Wu Kemei , Huang Liang 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Palladium(II)‐Catalyzed Ring Enlargement of 2‐(Arylmethylene)cyclopropylcarbinols: Strong Effect of Substituent Electronic Nature on the Reaction Pathway.
Authors: Tian Guo‐Qiang , Yuan Zhi‐Liang , Zhu Zhi‐Bin , Shi Min 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Diels—Alder Reactions of a Styrene‐Isocyanate: Unexpected Formation of a Pyridinone and Uracil.
Authors: Gfesser Gregory A. , Whittern David , Cowart Marlon D. , Faghih Ramin 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Catalytic Asymmetric Conjugate Reduction with Ethanol: A More Reactive System Pd(II)—iPr‐DUPHOS Complex with Molecular Sieves 4A.
Authors: Monguchi Daiki , Beemelmanns Christine , Hashizume Daisuke , Hamashima Yoshitaka , Sodeoka Mikiko 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Diarylboronic Acid Derivatives as a Catalytic Iminium Ion Generator in the Mannich‐Type Reaction Using Secondary Amines, Aldehydes, and Ketene Silyl Acetals.
Authors: Tanaka Yusuke , Hasui Tomoaki , Suginome Michinori 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Catalytic Asymmetric Dialkynylation Reaction of α‐Dinitrone by Utilizing Tartaric Acid Ester as a Chiral Auxiliary.
Authors: Serizawa Masakazu , Fujinami Shuhei , Ukaji Yutaka , Inomata Katsuhiko 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A New Class of Easily Activated Palladium Precatalysts for Facile C—N Cross‐Coupling Reactions and the Low Temperature Oxidative Addition of Aryl Chlorides.
Authors: Biscoe Mark R. , Fors Brett P. , Buchwald Stephen L. 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: An Efficient Selective Reduction of Aromatic Azides to Amines Employing BF3×OEt2/NaI: Synthesis of Pyrrolobenzodiazepines.
Authors: Kamal Ahmed , Shankaraiah N. , Markandeya N. , Reddy Ch. Sanjeeva 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: An Efficient Method for Demethylation of Aryl Methyl Ethers.
Authors: Zuo Li , Yao Shanyan , Wang Wei , Duan Wenhu 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Oxazolidin‐2‐one‐Promoted CuI‐Catalyzed Amidation of Aryl Halides and Cyclization of o‐Halobenzanilides.
Authors: Ma Heng Chang , Jiang Xuan Zhen 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Facile Synthesis, Crystal Structure, and Solid‐State Fluorescence of Dicyclohexane‐Anellated Anthracene.
Authors: Kitamura Chitoshi , Matsumoto Chika , Kawatsuki Nobuhiro , Yoneda Akio , Asada Kohei , Kobayashi Takashi , Naito Hiroyoshi 
Published: September 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.