含二氮杂荼酮结构新型聚芳醚系列高性能聚合物的合成与性能

从分子结构设计出发 ,以价廉易得的苯酚、苯酐为原料 ,经温和的工艺合成了结构全新的 4 ( 4′ 羟基苯基 ) 2 ,3 二氮杂萘 1 酮 (DHPZ) ,对其合成反应路线、合成反应动力学、反应机理进行了深入研究 .在大量实验研究基础上 ,结合分子立体结构的计算机模拟 ,确认其具有非共平面扭曲结构特征 ,其N—H键和O—H键具有类似的反应活性 ,是一种类似双酚的新单体 .以DHPZ与多种市售双卤单体如二氟二苯酮 (DFK)、二氯二苯砜 (DCS)、二氯二苯双酮 (DCKK)、二氯二苯腈 (DCBN)等经溶液亲核取代逐步聚合反应制得一系列含二氮杂萘酮结构的新型高性能聚醚砜 (PPES)、聚醚酮 (PPEK)、聚醚砜酮 (PPESK)、聚醚酮酮 (PPEKK)、聚醚砜酮酮(PPESKK)、聚醚腈酮 (PPENK)、聚醚腈砜 (PPENS)、聚醚腈砜酮 (PPENSK)等 ,对其结构进行了谱学表征 ,对其性能进行了全面测试 ,研究了其结构与性能关系 .谱学数据证明皆为无定型高聚物 .其玻璃化温度Tg 在 2 5 0～370℃之间 ,可以通过取代基团结构或主链上砜 酮基团比例进行调控 .在大量实验研究基础上 ,创造性提出“引入全芳环非共平面扭曲分子链结构赋予高聚物既耐高温又可溶解的优异综合性能”的分子结构设计理论 .在此分子设计理论指导下 ,设计并合成了含联苯二氮杂萘酮结构的新型二     

8-AminoBODIPYs: cyanines or hemicyanines? The effect of the coplanarity of the amino group on their optical properties

The role of the amino group twisting ability in the BODIPY photophysics for nonsterically hindered and constrained molecular structures was studied. When a coplanar disposition of the amino and the BODIPY core is feasible, a hemicyanine-like delocalized π-system gives rise to novel blue and efficient BODIPY laser dyes. The key role of such rotamer is confirmed by newly synthesized derivatives where the amino and the BODIPY core are electronically decoupled by steric repulsions.     

Strongly coupled excitonic states in H-aggregated single crystalline nanoparticles of 2,5-bis(4-methoxybenzylidene) cyclopentanone

This paper reports that extremely strongly coupled excitonic states were formed in H-aggregated monocrystalline nanosheets and semicrystalline nanowires of coplanar organic molecules of 2,5-bis(4-methoxybenzylidene) cyclopentanone, due to the highly regular face-to-face stacking of molecular excitons. It was demonstrated that the spectral absorption and fluorescence emission behaviors are dependent on the routes of molecular aggregation and the ordered degree of molecular arrangement in aggregated nanoparticles. In particular, the H-type aggregation of molecules through a highly ordered molecular arrangement in the monocrystalline nanosheets led to the formation of a new exciton coupling state with an energy band higher than that in normal semi-/noncrystalline H-aggregation. A strong symmetric absorption at higher energy bands was thus observed in the solution of nanosheets. Furthermore, the strongly coupled excitonic state may hold all the oscillator strength, leading to the extinction of the original intramolecular electronic transitions of individual molecules and the appearance of new strong absorption and fluorescence emissions at high-energy bands. These results show a perspective that the ability to control the molecular structure and its arrangement in aggregates holds promise for creating novel optical properties in molecular materials.     

A New Small-Molecule Donor Containing Non-Fused Ring π-Bridge Enables Efficient Organic Solar Cells with High Open Circuit Voltage and Low Acceptor Content

To achieve high open-circuit voltage (V_oc) and low acceptor content, the molecular design of a small-molecule donor with low energy loss (E_loss) is very important for solution-processable organic solar cells (OSCs). Herein, we designed and synthesized a new coplanar A−D−A structured organic small-molecule semiconductor with non-fused ring structure π-bridge, namely B2TPR , and applied it as donor material in OSCs. Owing to the strong electron-withdrawing effect of the end group and the coplanar π-bridge, B2TPR exhibits a low-lying highest occupied molecular orbital and strong crystallinity. Furthermore, benefiting from the coplanar molecular skeleton, the high hole mobility, balanced charge transport and reduced recombination were achieved, leading to a high fill factor (FF). The OSCs based on B2TPR : PC₇₁BM blend film (w/w=1 : 0.35) demonstrates a moderate power conversion efficiency (PCE) of 7.10 % with a remarkable V_oc of 0.98 V and FF of 64 %, corresponding to a low fullerene content of 25.9 % and a low E_loss of 0.70 eV. These results demonstrate the great potential of small-molecule with structure of B2TPR for future low-cost organic photovoltaic applications.     

Columnar metallomesogens derived from unsymmetrical pyrazoles

The synthesis and mesomorphism for two series of unsymmetrical pyrazoles and their nickel(II) complexes were described. This is the first example of nickel complexes exhibiting columnar phase. The derivatives with two alkoxy chains exhibited smectic A or smectic C phases; however, all derivatives with four alkoxy chains formed hexagonal columnar phases. In contrast, all nickel(II) complexes 1a formed hexagonal columnar phases. The crystal and molecular structures of 1-(4-propyloxyphenyl)-2-(3-(4-propyloxyphenyl)-1H-pyrazol-5-yl)ethanone were determined, and it crystallizes in the triclinic space group P-1. The overall molecular shape is considered as rod-shaped. The pyrazole and one phenyl ring were coplanar, however, they were not coplanar with other phenyl ring by a dihedral angle of ca. 66.2°. A dimeric structure formed by an intermolecular H-bond (2.11 Å) and a weak π-π interaction (3.51 Å) was observed, which was probably attributed to the formation of the mesophase. The XRD experiments confirmed their structures of the mesophases.     

Conformation-specific Raman bands and electronic conjugation in substituted thioanisoles

Nonresonant Raman spectra and conformational stability are studied for thioanisole (TA) and substituted analogues [4-XTA, X = NO(2) (1), CN (2), H (3), CH(3) (4), and NH(2) (5)] at the 4-position. The ring-substituent (SCH(3)) vibrational modes of out-of-plane bending and torsional types are calculated to have strong Raman scattering activities only for the vertical conformers. Agreement between observed and calculated Raman spectra is analyzed numerically. The conformational stability of the SCH(3) rotation changes systematically to the electron-withdrawing character of the substituents. The rotational barrier is calculated satisfactorily by B3LYP/6-31++G(d,p) calculations, whereas the second- to fourth-order M?ller-Presset perturbation theory and coupled-cluster with single- and double-excitation calculations tend to overestimate conformational energy barriers with respect to coplanar forms. The coplanar form is obtained for 1 and 2, whereas the vertical conformer is favorable for 4 and 5. The origin of the conformational energy difference, DeltaE, is demonstrated on the basis of canonical molecular orbitals and natural bond orbitals (NBOs) of the ground state. The natural bond orbital interaction between a nonbonding n(S) orbital of the S atom and a pi orbital of the benzene ring is shown to stabilize the coplanar form predominantly. A linear relationship is obtained between the energy of the highest occupied molecular orbitals and DeltaE. The n(S)-pi interaction energy, E(2), based on the NBO representation and the Hammet constants also change linearly with respect to DeltaE.     

Molecular dynamics simulation of TCDD adsorption on organo-montmorillonite

In this work, molecular dynamics simulation was applied to investigate the adsorption of Tetrachlorodibenzo-p-Dioxin (TCDD) on tetramethylammonium (TMA) and tetrapropylammonium (TPA) modified montmorillonite, with the aim of providing novel information for understanding the adsorptive characteristics of organo-montmorillonite toward organic contaminants. The simulation results showed that on both outer surface and interlayer space of TPA modified montmorillonite (TPA-mont), TCDD was adsorbed between the TPA cations with the molecular edge facing siloxane surface. Similar result was observed for the adsorption on the outer surface of TMA modified montmorillonite (TMA-mont). These results indicated that TCDD had stronger interaction with organic cation than with siloxane surface. While in the interlayer space of TMA-mont, TCDD showed a coplanar orientation with the siloxane surfaces, which could be ascribed to the limited gallery height within TMA-mont interlayer. Comparing with TMA-mont, TPA-mont had larger adsorption energy toward TCDD but smaller interlayer space to accommodate TCDD. Our results indicated that molecular dynamics simulation can be a powerful tool in characterizing the adsorptive characteristics of organoclays and provided additional proof that for the organo-montmorillonite synthesized with small organic cations, the available interlayer space rather than the attractive force plays the dominant role for their adsorption capacity toward HOCs.     

Synthesis and 1H NMR spectra of some 1-aryl-2,5-pyrrolidinediones

Three 1-aryl-2,5 pyrrolidinediones, two of which are novel, were prepared by reaction of the requisite primary aromatic amines with succinic anhydride, followed by treatment with acetic anhydride. The ¹H nmr spectra for the derivatives in which aryl is 1-naphthyl and 1-anthracenyl exhibit 32-line multiplets for the four aliphatic hydrogens, indicating that all four are in different environments. Examination of molecular models demonstrates that the pyrrolidinedione and aryl ring systems cannot be coplanar and that rotation about the nitrogen-aryl bond is restricted. Molecular mechanics calculations reveal that a dihedral angle of 50–65° for the two ring systems results in the minimum steric interaction energy.     

A cell electrofusion microfluidic chip using discrete coplanar vertical sidewall microelectrodes

A novel cell electrofusion microfluidic chip using discrete coplanar vertical sidewall electrodes has been designed, fabricated, and tested. The device contains a serpentine-shaped microchannel with 22 500 pairs of vertical sidewall microelectrodes patterned on two opposing vertical sidewalls of the microchannel. The adjacent microelectrodes on each sidewall are separated by coplanar SiO(2) -Polysilicon-SiO(2) /silicon. This design of coplanar discrete vertical sidewall electrodes eliminates the "dead area" present in previous designs using continuous three-dimensional (3D) protruding sidewall electrodes, and generates uniform electric field along the height of the microchannel, leading to a lower voltage required for cell fusion compared to designs using 2D thin-film electrodes. This device is tested to fuse NIH3T3 cells under a low voltage (～9 V). Almost 100% cells are aligned to the edge of the discrete microelectrodes, and cell-cell pairing efficiency reaches 70%. The electrofusion efficiency is above 40% of the total cells loaded into the device, which is much higher than traditional fusion methods and existing microfluidic devices using continuous 3D protruding sidewall microelectrodes.     

结构受阻的取代的苯乙烯基吡嗪衍生物作为荧光探针的研究

本工作合成了两种旋转受阻取代的苯乙烯基吡嗪衍生物。详细研究了环境温度、极性和粘度对其光物理及发光行为的影响。结果表明两化合物在基态时可能存在着"平面构象与扭曲构象"间的平衡, 环境的温度、极性和粘度对于化合物存在的构象有很大影响。扭曲构象为较好的发光构象。分子受激后, 平面构象可经旋转松弛到扭曲构象。两化合物的荧光量子产率在室温条件下基本不随溶剂极性变化而变, 仅与溶剂粘度有关, 利用该性质可建议其作为一种有效的粘度荧光探针。     

High-efficiency switching effect in porphyrin-ethyne-benzene conjugates

We have explored the electronic transport properties of porphyrin-ethyne-benzene conjugates using an ab initio method. The results indicate that these ethyne-bridged phenyl porphyrin molecules can be used as candidates for molecular switching devices. The coplanar conformation of phenyl and porphyrin moieties allows a far larger current than the perpendicular conformation due to the near vanishing overlap of the frontier molecular orbitals (π channels) in the porphyrin and phenyl parts in the latter. Higher current ratios of ON/OFF states can be obtained if amino or nitro substituent is placed at the position meta to the bridge connecting the π systems of the molecule. The substituent group affects the electronic state energy of the entire molecule in coplanar conformation, while only affecting the local part in perpendicular conformation. More complex ethyne-bridged diphenyl porphyrin molecules are found to yield more complex and interesting switching effects. Our results suggest that such molecular wires composed of appropriate π-conjugated molecules, can generally display perfect switching function and the efficiency can be tuned flexibly by adding certain substituent groups to the conjugates.     

Engineering control over the conformation of the alkyne-aryl bond by the introduction of cationic charge

A novel arylene-ethynylene molecule has been synthesized. This molecule is more stable in a coplanar form than in a twisted form as in the cases of typical arylene-ethynylene molecules. When the cationic charge was introduced into the pi-conjugated system, the perpendicularly twisted form became more stable than the coplanar state. The conformational change was controlled by introduction and removal of cationic charge, confirmed by the absorption and fluorescence spectroscopy and DFT calculation.     

Synthesis and properties of novel C3-symmetric coplanar chromophores

New synthetic pathways for novel C(3)-symmetric molecules featured with a thiophene-fused six-five-five carbon-bridged coplanar core structure have been established. The incorporation of thiophene as the constituent of a C(3)-symmetric core provides effective modulation of the physical properties and imparts extra flexibility for π-conjugated functionalization stemming from either the embedded thiophene or pendant aryl substitutions.     

Divinylketone: Conformational preferences. Molecular geometry and vibrational force field in the ground state

The conformational preferences of the molecule 1,4-pentadien-3-one (divinylketone) have been studied by ab initio molecular orbital calculations and discussed in terms of interaction between molecular fragments. The calculations predict a molecular ground state having a fully coplanar s-cis, s-cis conformation. In addition, we find three other structures that represent local minima on the energy surface. These are a fully coplanar s-cis, s-trans form, and two nonplanar s-trans, s-trans forms having symmetries C₂ and C_1h, respectively. The energies of these forms relative to the ground state are 7.5, 19.2, and 35.9 kJ/mol, respectively. The coplanar s-trans, s-trans form represents a saddle point on the energy surface. All conformers and the saddle point have been completely geometry optimized by the gradient technique. For the ground state a complete in-plane harmonic force field has been evaluated.     

The molecular structure of N-benzylidene-aniline

The molecular structure of N-benzylidene-aniline has been studied experimentally by the gas electron diffraction method, and also by molecular mechanics calculations. Both approaches gave the same results for the most stable conformer of the free molecule. The phenyl ring bonded to the carbon end of the CN bond was found to be coplanar with this bond, while the other phenyl ring was extensively (ca. 52°) rotated about the NΦ bond.     

Experimental and theoretical (e,2e) ionization cross sections for a hydrogen target at 75.3 eV incident energy in a coplanar asymmetric geometry

Very recently it was shown that the molecular three-body distorted wave (M3DW) approach gives good agreement with the shape of the experimental data for electron-impact ionization of H(2) in a coplanar symmetric geometry, providing the incident electrons have an energy of 35 eV or greater. One of the weaknesses of these studies was that only the shape of the cross section could be compared to experiment, since there was no absolute or relative normalization of the data. Here we report a joint experimental/theoretical study of electron-impact ionization of H(2) in a coplanar asymmetric geometry where the energy of the incident electron was fixed, and different pairs of final state electron energies were used. In this case, the experimental data can be normalized such that only one renormalization factor is required. It is shown that the M3DW is pretty good in agreement with experiment. However, a better treatment of polarization and exchange between the continuum and bound state electrons is required before quantitative agreement between experiment and theory is achieved.     

AC frequency characteristics of coplanar impedance sensors as design parameters

Glass-based microchannel chips were fabricated using photolithographic technology, and Pt thin-film microelectrodes, as coplanar impedance sensors, were integrated on them. Longitudinal design parameters, such as interelectrode spacing and electrode width, of coplanar impedance sensors were changed to determine AC frequency characteristics as design parameters. Through developing total impedance equations and modeling equivalent circuits, the dominant components in each frequency region were illustrated for coplanar impedance sensors and the measured results were compared with fitted values. As the ionic concentration increased, the value of the frequency-independent region decreased and cut-off frequencies increased. As the interelectrode spacing increased, cut-off frequencies decreased and total impedance increased. However, the width of each frequency-independent region was similar. As the electrode area increased, f(low) decreased but f(high) was fixed. We think that the decrease in R(Sol) dominated over the influence of other components, which resulted in heightening f(low) and f(high). The interelectrode spacing is a more significant parameter than the electrode area in the frequency characteristics of coplanar sensors. The deviation of experimentally obtained results from theoretically predicted values may result from the fringing effect of coplanar electrode structure and parasitic capacitance due to dielectric substrates. We suggest the guidelines of dominant components for sensing as design parameters.     

Molecular and Crystal Structure of 7—Hydroxy—6,8—dimethoxyl—coumarin

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5‐Amino‐4‐(4‐diethyl­amino­phenyl)‐2‐(4‐hydroxy­phenyl)‐7‐(pyrrolidin‐1‐yl)‐1,6‐naphthyridine‐8‐carbo­nitrile

In the title compound, C₂₉H₃₀N₆O, the naphthyridine moiety is planar with a dihedral angle between the fused rings of 1.9 (1)°. The phenol ring is nearly coplanar, while the diethyl­amino­phenyl substituent is orthogonal to the central naphthyridine ring and the pyrrolidine ring makes an angle of 11.2 (1)° with it. The O atom of the hydroxy substituent is coplanar with the phenyl ring to which it is attached. The molecular structure is stabilized by a C—H?N‐type intramolecular hydrogen bond and the packing is stabilized by intermolecular C—H?π, O—H?N and N—H?O hydrogen bonds.     

Distorted wave Born and three-body distorted wave Born approximation calculations of the fully differential cross section for electron-impact ionization of nitrogen molecules

Currently there are no reliable theoretical approaches for calculating fully differential cross sections (FDCSs) for low-energy electron-impact ionization of large molecules. We have recently proposed the orientation-averaged molecular orbital (OAMO) for calculating cross sections averaged over molecular orientations. In this paper, we use the OAMO to calculate distorted wave Born approximation (DWBA) and molecular three-body distorted wave (M3DW) Born approximation FDCS for electron-impact ionization of the nitrogen molecule. Both coplanar symmetric and asymmetric FDCSs are investigated in the energy range of 35.6-400 eV. By comparing with the experimental data, we found that the M3DW is reasonably accurate in this energy range. We also found that the postcollision interaction plays a sufficiently important role and that the DWBA is not reliable.