Assembling metals and clusters around an octaphosphine ligand based on N-substituted bis(diphenylphosphanyl)amines: structural characterization of dendrimer-like Co12 and Co16 branched clusters

A polypodal ligand based on an aromatic ring decorated by four dppa-type diphosphine moieties has been used to prepare Pt(II) complexes and to assemble four tricobalt or tetracobalt carbonyl clusters, leading to centrosymmetric Co12 and Co16 "clusters of clusters" which were characterized by X-ray diffraction.     

In Situ Synthesis of AIEgen-based Porous Organic Polymer Films by Interfacial Amino-yne Click Polymerization for Efficient Light-Harvesting

We developed a catalyst-free, atom-economical interfacial amino-yne click polymerization to in situ synthesize new aggregation-induced emission luminogen (AIEgen)-based free-standing porous organic polymer films at room temperature. The crystalline properties of POP films were confirmed by powder X-ray diffraction and high-resolution transmission electron microscopy. The good porosity of these POP films was proved by their N₂ uptake experiments. The thickness of POP films can be easily regulated from 16 nm to ≈1 μm by adjusting monomer concentration. More importantly, these AIEgen-based POP films show bright luminescence with high absolute photoluminescent quantum yields up to 37.8 % and good chemical and thermal stability. The AIEgen-based POP film can encapsulate an organic dye (e.g., Nile red) to further form an artificial light-harvesting system with a large red-shift (Δλ=141 nm), highly efficient energy-transfer ability (Φ_ET=91 %), and high antenna effect (11.3).     

5-[4'-正庚基-氧-联苯基-4-氧-羰基]基-1-正戊炔的晶体结构研究

由于共轭聚合物的光致发光和电致发光性能, 有望成为制造全塑性发光二极管的材料, 因此近年来已引起人们的研究兴趣[1]. 聚乙炔是一种典型的共轭聚合物, 其不稳定性和难加工性限制了它的应用. 而含联苯液晶基元的取代聚乙炔, 不仅其难加工性得到了改善, 提高了稳定性, 而且赋予了聚合物液晶性, 因此有望开发出一批新型的高性能材料[2]. 目前对这类新型取代乙炔聚合物及其单体的凝聚态结构的报道还较少. 本文通过WAXD, TEM和AFM等手段对小分子液晶5-[4′-正庚基-氧-联苯基-4-氧-羰基]基-1-正戊炔(A3E′O7)的晶体结构进行了研究.     

Preparation of Functional Poly(aroyltriazole)s by Metal-Free Click Polymerization

Functional poly(aroyltriazoles) (PATAs) were synthesized by heating mixtures of bis(aroylacetylene)s and diazides in polar solvents such as DMF/toluene at a moderate temperature of 100 °C with high molecular weights (M_w up to 17 200) and regioregularities (1,4-regioisomeric ratio up to ∼95%) in high yields (up to ∼95%). The obtained polymers are soluble in common organic solvents and are thermally stable. The PATAs containing triphenylamine units emit visible light and show unique solvatochromism, exhibiting large two-photon absorption cross sections due to the intramolecular charge transfer between their electron-donating triphenylamine and electron-accepting aroyltriazole units. The tetraphenylethene (TPE)-functionalized polymer shows intriguing aggregation-induced emission phenomenon, that is, the polymer is weakly emissive in its solution state but emit strongly in its aggregate/solid state with quantum yield of ∼7.1%.     

Restriction of Access to the Dark State: A New Mechanistic Model for Heteroatom‐Containing AIE Systems

Restriction of intramolecular motion (RIM), as the working mechanism of aggregation‐induced emission (AIE), cannot fully explain some heteroatom‐containing systems. Now, two excited states are taken into account and a mechanism, restriction of access to dark state (RADS), is specified to elaborate RIM and complete the picture of AIE mechanism. A nitrogen‐containing molecule named APA is chosen as a model compound; its weak fluorescence in solution is ascribed to the easy access from the bright (π,π*) state to the close‐lying dark (n,π*) state. By either metal complexation or aggregation, the dark state is less accessible due to restriction of the molecular motion leading to the dark state and elevation of the dark state energy, thus the bright state emission is restored. RADS is powerful in elucidating the AIE effect of molecules with excited states favoring non‐radiative decay, including overlap‐forbidden states such as (n,π*) and CT states, spin‐forbidden triplet states, and so on.     

Uniform in N global well-posedness of the time-dependent Hartree–Fock–Bogoliubov equations in $$\mathbb {R}^{1+1}$$

We prove the global well-posedness of the time-dependent Hartree–Fock–Bogoliubov (TDHFB) equations in \(\mathbb {R}^{1+1}\) with two-body interaction potential of the form \(N^{-1}v_N(x) = N^{\beta -1} v(N^\beta x)\) where \(v\ge 0\) is a sufficiently regular radial function, i.e., \(v \in L^1(\mathbb {R})\cap C^\infty (\mathbb {R})\). In particular, using methods of dispersive PDEs similar to the ones used in Grillakis and Machedon (Commun Partial Differ Equ 42:24–67, 2017), we are able to show for any scaling parameter \(\beta >0\) the TDHFB equations are globally well-posed in some Strichartz-type spaces independent of N, cf. (Bach et al. in The time-dependent Hartree–Fock–Bogoliubov equations for Bosons, 2016. arXiv:1602.05171).     

硝基苯衍生物结构与其淬灭聚(2,5-二戊氧基对亚苯基亚乙炔基)荧光效率的关系

聚对亚苯基亚乙炔基(polyphenyleneethynylenes,PPEs)、聚噻吩(PTs)等作为具有共轭结构的电荷给体,在与含硝基、氰基等电荷受体发生电荷转移络合作用时,其荧光强度会随电荷受体结构的不同而产生不同程度的淬灭,而且响应灵敏度明显高于一般荧光小分子化合物[1~4].这是因为荧光小     

自掺杂基团对聚苯胺自组装膜电化学性能的影响

基于离子相互作用,实现了以聚苯胺(PANI)为聚阳离子,以聚(邻氨基苯甲酸)(PCAN)、聚(邻氨基苯磺酸)(PSAN)为聚阴离子的层-层自组装,形成层厚均匀的全共轭超薄功能膜.由于磺酸基—SO3-的电负性高于—COO-,使得PANI-PSAN自组装膜沉积量小于PANI-PCAN;电化学实验结果显示,由于PCAN和PSAN的导电性均弱于PANI,所以两种自组装膜的电化学性能取决于PANI,但同时受到羧酸、磺酸基团的较大影响,使得PANI-PCAN自组装膜的电化学性能要优于PANI-PSAN.     

Unusual Through-Space Interactions between Oxygen Atoms that Mediate Inverse Morphochromism of an AIE Luminogen

We have studied the photophysics of tetrafurylethene, an aggregation-induced emission luminogen with exceptionally short intramolecular O−O distances of 2.80 Å and a significant red-shifted morphochromism (27 nm) when going from the aggregate to the crystal. The short O−O distances, which are substantially smaller than the sum of the van der Waals radii (3.04 Å), are due to the fact that the oxygen atoms act as an electronic bridge connecting the furan rings on opposite ends of the central double bond, giving rise to a circular delocalization of the π-electron density across the rings. In the excited state the O−O distance is further reduced to 2.70 Å; the increased O−O interaction causes a narrowing of the HOMO–LUMO gap, resulting in the red morphochromism of the emission. Our results show the structural origin of the red-shifted emission lies in close O−O contacts, paving the way for understanding the clusteroluminescence of oxygen-rich non-conjugated systems that emit visible light.     

In vivo monitoring of tissue regeneration using a ratiometric lysosomal AIE probe

Tissue regeneration is a crucial self-renewal capability involving many complex biological processes. Although transgenic techniques and fluorescence immunohistochemical staining have promoted our understanding of tissue regeneration, simultaneous quantification and visualization of tissue regeneration processes is not easy to achieve. Herein, we developed a simple and quantitative method for the real-time and non-invasive observation of the process of tissue regeneration. The synthesized ratiometric aggregation-induced-emission (AIE) probe exhibits high selectivity and reversibility for pH responses, good ability to map lysosomal pH both in vitro and in vivo, good biocompatibility and excellent photostability. The caudal fin regeneration of a fish model (medaka larvae) was monitored by tracking the lysosomal pH change. It was found that the mean lysosomal pH is reduced during 24–48 hpa to promote the autophagic activity for cell debris degradation. Our research can quantify the changes in mean lysosomal pH and also exhibit its distribution during the caudal fin regeneration. We believe that the AIE-active lysosomal pH probe can also be potentially used for long-term tracking of various lysosome-involved biological processes, such as tracking the stress responses of tissue, tracking the inflammatory responses, and so on.

An AIE-active ratiometric probe for the first time achieved the long-term quantification of lysosomal pH during the medaka larva''s caudal fin regeneration.