137 research outputs found
4-(N,N-Dimethylamine)benzonitrile (DMABN) derivatives with boronic acid and boronate groups: new fluorescent sensors for saccharides and fluoride ion{
Two DMABN derivatives with boronic acid/boronate groups 1 and 2 were designed and synthesized for sensing saccharides and F 2 , respectively. Fluorescent spectral changes were observed for 1 after reaction with fructose, galactose, mannose and glucose, and the corresponding binding constants were estimated. The results show that compound 1 can bind fructose more strongly than other saccharides tested. Interestingly, both absorption and fluorescence spectral changes occurred for compound 2 after addition of F 2 , indicating that compound 2 is a potentially selective sensor for F 2
Synthesis, structure and electrical properties of the two-dimensional organic conductor, (BEDT-TTF)2BrI2
Single crystals of α-(BEDT-TTF)2BrI2 and β-(BEDT-TTF)2BrI2 were prepared using standard electrochemical techniques in nitrogen saturated benzonitrile using containing (n-C4H10)NBrI2 as supporting electrolyte. The crystals have nearly identical structure features of α-(BEDT-TTF)2I3 and β-(BEDT-TTF)2I3, except that the BrI−2 anions are disordered in α-(BEDT-TTF)2BrI2 and β-(BEDT-TTF)2BrI2. Their electrical behavior is different from the corresponding α-,β-(BEDT-TTF)2I3 species
Self-assembly of gold nanoparticles to carbon nanotubes using a thiol-terminated pyrene as interlinker
Abstract Gold nanoparticles were self-assembled onto the surface of solubilized carbon nanotubes through an interlinker of bi-functionalized molecule (PHT) terminated with pyrenyl unit at one end and thiol group at the other end. While the fluorescence of PHT is quenched moderately by the carbon nanotubes, the fluorescence is almost totally quenched by the further binding of gold nanoparticles. The enhancement of the Raman responses of nanotubes by the gold nanoparticles is also observed. These results imply there are charge transfer interactions between nanotubes and gold nanoparticles
Recommended from our members
Bottom-up growth of n-type monolayer molecular crystals on polymeric substrate for optoelectronic device applications.
Self-assembly of monolayers of functional molecules on dielectric surfaces is a promising approach for the development of molecular devices proposed in the 1970s. Substrate chemically bonded self-assembled monolayers of semiconducting conjugated molecules exhibit low mobility. And self-assembled monolayer molecular crystals are difficult to scale up and limited to growth on substrates terminated by hydroxyl groups, which makes it difficult to realize sophisticated device functions, particularly for those relying on n-type electron transport, as electrons suffer severe charge trapping on hydroxyl terminated surfaces. Here we report a gravity-assisted, two-dimensional spatial confinement method for bottom-up growth of high-quality n-type single-crystalline monolayers over large, centimeter-sized areas. We demonstrate that by this method, n-type monolayer molecular crystals with high field-effect mobility of 1.24 cm2 V-1 s-1 and band-like transport characteristics can be grown on hydroxyl-free polymer surface. Furthermore, we used these monolayer molecular crystals to realize high-performance crystalline, gate-/light-tunable lateral organic p-n diodes
Effect of Addition Groups on the Redox Properties of Fullerenes
采用循环伏安法和微分脉冲伏安法对比地研究了包括五种C60的衍生物及四种C70的衍生物的电化学性质.结果表明,推电子基团的引入使得富勒烯的氧化还原电位负移,这种负移的程度与加成基团的性质、个数和富勒烯的性质有关.对于C60和C70的单加成产物,负移的范围是0.08~0.20V.而对于C60的双加成和三加成产物负移的范围分别为0.30~0.32V和0.53~0.58V.同时由于电位的负移大部分衍生物在低于+1.5V(vs.SCE)观察到了氧化峰,而C60和C70本身的氧化高达+1.7V(vs.SCE).特别是对于C70的双加成产物在+0.45V(vs.SCE)出现了一个不可逆氧化峰,但是,对于同样加成基团的C60双加成产物的氧化却在+0.90V(vs.SCE),说明由于推电子基团的双加成引入,明显改变了C70的电负性.Electrochemical properties of fullerene derivatives, including five C60 derivatives and four C70 derivatives, were studied systematically and comparatively by cyclic voltammetry and differential pulse wave voltammetry. The addition of the electrondonating groups on the fullerenes caused negative shift of the redox potentials of the fullerenes. The extent of the negative shift depends on the number and properties of the addition groups, and on the nature of the fullerenes. 0.08~0.20 V negative shift was observed for C60 and C70 monoadducts, 0.30~0.32 V for bisadduct and 0.53~0.58 V for triadduct of C60. Meanwhile, the oxidation waves of most of these derivatives appeared on their cyclic voltammograms. Particularly, an irreversible oxidation of the C70 bisadduct took place at +0.45 V (vs. SCE), while that of C60 bisadduct was at +0.90 V (vs. SCE), indicating that the electronegativity of C70 was greatly reduced by the bisaddition of the electrondonating groups.作者联系地址:中国科学院化学研究所Author's Address: Insti. of Chem., The Chinese Academy of Sinences, Beijing 10008
Recommended from our members
Investigation of Electrode Electrochemical Reactions in CH3 NH3 PbBr3 Perovskite Single-Crystal Field-Effect Transistors.
Optoelectronic devices based on metal halide perovskites, including solar cells and light-emitting diodes, have attracted tremendous research attention globally in the last decade. Due to their potential to achieve high carrier mobilities, organic-inorganic hybrid perovskite materials can enable high-performance, solution-processed field-effect transistors (FETs) for next-generation, low-cost, flexible electronic circuits and displays. However, the performance of perovskite FETs is hampered predominantly by device instabilities, whose origin remains poorly understood. Here, perovskite single-crystal FETs based on methylammonium lead bromide are studied and device instabilities due to electrochemical reactions at the interface between the perovskite and gold source-drain top contacts are investigated. Despite forming the contacts by a gentle, soft lamination method, evidence is found that even at such "ideal" interfaces, a defective, intermixed layer is formed at the interface upon biasing of the device. Using a bottom-contact, bottom-gate architecture, it is shown that it is possible to minimize such a reaction through a chemical modification of the electrodes, and this enables fabrication of perovskite single-crystal FETs with high mobility of up to ≈15 cm2 V-1 s-1 at 80 K. This work addresses one of the key challenges toward the realization of high-performance solution-processed perovskite FETs
Recommended from our members
π-Conjugated molecules with fused rings for organic field-effect transistors: design, synthesis and applications
π-Conjugated molecular materials with fused rings are the focus of considerable interest in the emerging area of organic electronics, since the combination of excellent charge carrier mobility and high stability may lead to their practical applications. This tutorial review discusses the synthesis, properties and applications of π-conjugated organic semiconducting materials, especially those with fused rings. The achievements to date, the remaining problems and challenges, and the key research that needs to be done in the near future are all discussed
Ultra-Sensitivity Glucose Sensor Based on Field Emitters
A new glucose sensor based on field emitter of ZnO nanorod arrays (ZNA) was fabricated. This new type of ZNA field emitter-based sensor shows high sensitivity with experimental limit of detection of 1 nM glucose solution and a detection range from 1 nM to 50 μM in air at room temperature, which is lower than that of glucose sensors based on surface plasmon resonance spectroscopy, fluorescence signal transmission, and electrochemical signal transduction. The new glucose sensor provides a key technique for promising consuming application in biological system for detecting low levels of glucose on single cells or bacterial cultures
- …