聚{11-[(4'-正庚氧基-4-联苯基)羰基]氧-1-十一炔}的相结构与相转变

采用示差扫描量热法(DSC)、一维(1D)、二维(2D)广角X-射线衍射(WAXD)和偏光显微镜(PLM)等研究手段对聚{11-[(4'-正庚氧基-4-联苯基)羰基]氧-1-十一炔}(PA-9,7)的本体相转变和相结构进行研究,并采用分子动力学方法对相结构进行模拟.结果表明,样品的相转变为近晶B相(SmB)(→)近晶A相(SmA)(→)各向同性态(Iso).在近晶B相中,侧链在层状结构中排列成具有六次对称性的准长程有序结构.     

A note on a derivation method for SDE models: Applications in biology and viability criteria

We discuss a method, which was popularized by E. J. Allen and that is frequently used in applications to construct SDE models. The derivation procedure is based on information about the elementary processes involved in the dynamics and their corresponding probabilities. We formulate criteria for the viability of the resulting models. In particular, explicit necessary and sufficient conditions are deduced for the non-negativity and/or boundedness of solutions. Moreover, we show that the class of deterministic models for which the construction leads to an admissible SDE extension is strongly limited. Several examples are presented to illustrate the implications of our results.     

One stone,three birds: one AIEgen with three colors for fast differentiation of three pathogens

Visually identifying pathogens favors rapid diagnosis at the point-of-care testing level. Here, we developed a microenvironment-sensitive aggregation-induced emission luminogen (AIEgen), namely IQ–Cm, for achieving fast discrimination of Gram-negative bacteria, Gram-positive bacteria and fungi by the naked-eye. With a twisted donor–acceptor and multi-rotor structure, IQ–Cm shows twisted intramolecular charge transfer (TICT) and AIE properties with sensitive fluorescence color response to the microenvironment of pathogens. Driven by the intrinsic structural differences of pathogens, IQ–Cm with a cationic isoquinolinium moiety and a membrane-active coumarin unit as the targeting and interacting groups selectively locates in different sites of three pathogens and gives three naked-eye discernible emission colors. Gram-negative bacteria are weak pink, Gram-positive bacteria are orange-red and fungi are bright yellow. Therefore, based on their distinctive fluorescence response, IQ–Cm can directly discriminate the three pathogens at the cell level under a fluorescence microscope. Furthermore, we demonstrated the feasibility of IQ–Cm as a visual probe for fast diagnosis of urinary tract infections, timely monitoring of hospital-acquired infection processes and fast detection of molds in the food field. This simple visualization strategy based on one single AIEgen provides a promising platform for rapid pathogen detection and point-of-care diagnosis.

A simple AIEgen with three emission colors achieves rapid identification of Gram-negative bacteria, Gram-positive bacteria and fungi.     

Structural control of the photoluminescence of silole regioisomers and their utility as sensitive regiodiscriminating chemosensors and efficient electroluminescent materials

We synthesized a group of silole regioisomers 1(x,y), whose photoluminescence varied dramatically with its regiostructure. By internally hindering the intramolecular rotation, we succeeded in creating a novel silole (1(3,4)) that is strongly luminescent in solutions and whose fluorescence quantum yield in acetone is as high as 83%. We revealed that 1(3,4) was a sensitive chemosensor capable of optically discriminating nitroaromatic regioisomers of p-, o-, and m-nitroanilines. Against general belief, crystal formation of 1(2,4) blue-shifted its emission color and boosted its emission efficiency. The light-emitting diode based on the crystal of 1(2,4) emitted a strong blue light (464 nm) in a high current efficiency (5.86 cd/A).     

New carbazole-substituted siloles for the fabrication of efficient non-doped OLEDs

New aggregation-induced emission molecules of carbazole-substituted siloles are prepared, based on which efficient non-doped OLEDs are fabricated, offering high external quantum efficiencies of up to 5.63%.     

SYNTHESIS AND PHOTOLUMINESCENCE OF AN ANTHRACENE-CONTAINING HYPERBRANCHED POLY（ARYLENEETHYNYLENE）

A hyperbranched poly（aryleneethynylene） containing anthracene chromophore was synthesized by palladiumcatalyzed cross-coupling reaction of 2,4,6-triiodophenyl 9-anthracenylcarboxylate with 9,9-bis[4-（2-propynyloxy）phenyl]- 9H-fluorene. The structure and properties of the polymer are characterized and evaluated by NMR, IR, UV, PL and TGA analyses. The polymer is soluble in common organic solvents, possesses high thermal stability （Td 〉 330℃）, and emits a strong blue light of 465 nm in both solution and solid states.     

Theoretical analysis of the influence of the adsorption process on the voltammetric curves in the case of a second order adsorption step followed by a first order charge transfer reaction: Part III. Variation of the transfer coefficient and application to semiconductor electrodes in l.p.s.v. and s.s.c.v.

The kinetic behaviour of a two-step sequential reaction including a 2nd order adsorption process is treated theoretically in the case of semiconductor electrodes. It is shown that the electronic structure of the semiconductor can be taken into account in some simplified cases by introducing a formal transfer coefficient comprised between 0 and 1 and potential independent. In both linear potential sweep voltammetry and steady state cyclic voltammetry, the usual characteristic features (E_M, _M, i_M) of the voltammetric curves are calculated as a function of the sweep rate for different values of the transfer coefficient.     

Etude dans la série des radicaux hétérocycliques. Partie XV. Décomposition aprotique de l'amino-6-éthyl-2-benzothiazole dans des substrats aromatiques et hétéroaromatiques: préparation des mésityl-6- et furyl-6-éthyl-2-benzothiazoles,des sels quaternaires et des spiropyrannes correspondants

Study of heteroaromatic radicals. Part XV .

1 Partie XIV: cf. [1].

Aprotic decomposition of 6-amino-2-ethylbenzothiazole in aromatic and heteroaromatic substrates: preparation of 6-mesityl- and 6-furyl-2-ethylbenzothiazoles and of the corresponding quaternary salts and spyropyrans In the presence of excess isopentyl nitrite in aprotic solvent, the 6-amino-2-ethyl-benzothiazole leads to 6-aryl- and 6-heteroaryl-2-ethylbenzothiazoles 1 to 14 in ca. 20–50% yield (Scheme 1, Table 1). The 2-ethyl-6-benzothiazolyl radicals generated during these reactions exhibit a weak electrophilic character (Table 2). Preparatively this method has been applied to the synthesis of 6-mesityl- and 6-furyl-2-ethylbenzothiazoles 6 and 7 , which were used to prepare the corresponding quaternary salts 15 , 16 and the spiropyrans 19, 20 (Scheme 4).     

Chiral assembly of organic luminogens with aggregation-induced emission

Chirality is important to chemistry, biology and optoelectronic materials. The study on chirality has lasted for more than 170 years since its discovery. Recently, chiral materials with aggregation-induced emission (AIE) have attracted increasing interest because of their fascinating photophysical properties. In this review, we discussed the recent development of chiral materials with AIE properties, including their molecular structures, self-assembly and functions. Generally, the most effective strategy to design a chiral AIE luminogen (AIEgen) is to attach a chiral scaffold to an AIE-active fluorophore through covalent bonds. Moreover, some propeller-like or shell-like AIEgens without chiral units exhibit latent chirality upon mirror image symmetry breaking. The chirality of achiral AIEgens can also be induced by some optically active molecules through non-covalent interactions. The introduction of an AIE unit into chiral materials can enhance the efficiency of their circularly polarized luminescence (CPL) in the solid state and the dissymmetric factors of their helical architectures formed through self-assembly. Thus, highly efficient circularly polarized organic light-emitting diodes (CPOLEDs) with AIE characteristics are developed and show great potential in 3D displays. Chiral AIEgens are also widely utilized as “turn on” sensors for rapid enantioselective determination of chiral reagents. It is anticipated that the present review can entice readers to realize the importance of chirality and attract much more chemists to contribute their efforts to chirality and AIE study.

This review highlights the recent development of chiral materials with aggregation-induced emission properties, including their molecular structures, self-assembly and functions.