An artificial light‐harvesting system with sequential energy‐transfer process was fabricated based on a supramolecular strategy. Self‐assembled from the host–guest complex formed by water‐soluble pillar[5]arene (WP5), a bola‐type tetraphenylethylene‐functionalized dialkyl ammonium derivative (TPEDA), and two fluorescent dyes, Eosin Y (ESY) and Nile Red (NiR), the supramolecular vesicles achieve efficient energy transfer from the AIE guest TPEDA to ESY. ESY can function as a relay to further transfer the energy to the second acceptor NiR and realize a two‐step sequential energy‐transfer process with good efficiency. By tuning the donor/acceptor ratio, bright white light emission can be successfully achieved with a CIE coordinate of (0.33, 0.33). To better mimic natural photosynthesis and make full use of the harvested energy, the WP5⊃TPEDA‐ESY‐NiR system can be utilized as a nanoreactor: photocatalyzed dehalogenation of α‐bromoacetophenone was realized with 96 % yield in aqueous medium.

Articles you may be interested inStudy the effect of engagement force of ultrasound transducer on crack detectability in sonic IR imaging AIP Conf. Proc. 1511, 532 (2013); 10.1063/1.4789093Modeling turbine blade crack detection in sonic IR imaging with a method of creating flat crack surface in finite element analysis AIP Conf.Finite element modeling of the heating of cracks during sonic infrared imaging High-frequency pulsed sonic excitation is combined with an infrared camera to image surface and subsurface defects. Irreversible temperature increases on the surface of the object, resulting from localized heating in the vicinity of cracks, disbonds, or delaminations, are imaged as a function of time prior to, during, and following the application of a short pulse of sound. Pulse durations of 50 ms are sufficient to image such defects, and result in surface temperatures variations of ϳ2°C above the defect. As an example, sonic infrared images are presented for two fatigue cracks in Al and of interply delamination impact damage in a graphite-fiber-reinforced polymer composite. The shorter of the two fatigue cracks is ϳ0.7 mm in length, and is tightly closed. Thus, this new technique is sensitive, and capable of rapid imaging of defects under wide surface areas of an object.

The polymerization of bio-renewable myrcene (MY), using a cationic β-diimidosulfonate lutetium catalyst in high activity, afforded an unprecedented isotactic 3,4-polymyrcene (PMY) with a low Tg (-42 °C). Based on this result, the random and block copolymerization of myrcene and isoprene (IP) resulted in novel elastomers that comprise the amorphous iso-3,4-PMY and iso-3,4-PIP sequences.

The rare-earth metal complexes bearing NSN-bidentate β-diimidosulfonate ligands (RNSN dipp )Ln-(CH 2 SiMe 3 ) 2 (THF) n (R = Ph, Ln = Lu (1a), n = 1, Y (1b), n = 2, Sc (1c), n = 1; R = PhNMe 2 , Ln = Lu (1d), n = 1) were synthesized by treatment of the ion-pairs [Ln(CH 2 SiMe 3 ) 2 (THF) x ][BPh 4 ] with equimolar amount of the ligand lithium salts (RNSN dipp )Li(THF) 2 (NSN dipp = S(NC 6 H 4 i Pr 2 -2,6) 2 ). Addition reaction between lutetium tris(alkyl)s, Ln(Z) 3 (THF) n and NSN dipp gave the corresponding dialkyl complexes (ZNSN dipp )Lu(Z) 2 (THF) n (Z = CH 2 SiMe 3 , n = 1 (1e); Z = o-CH 2 C 6 H 4 NMe 2 , n = 0 (1f)). Deprotonation of β-imidophosphonamido ligands H−NPN dipp and H−NPN Et (NPN dipp = Ph 2 P(NC 6 H 3 i Pr 2 -2,6) 2 , NPN Et = PPh 2 (NC 6 H 3 i Pr 2 -2,6)(NC 6 H 4 -Et-2)) with Lu(CH 2 SiMe 3 ) 3 (THF) 2 yielded the corresponding dialkyl complexes (NPN dipp )Lu(CH 2 SiMe 3 ) 2 (THF) ( 2) and (NPN Et )Lu(CH 2 SiMe 3 ) 2 (THF) (3). All the complexes had been structurally well-defined, and 1a, 1b, 1e, 2, and 3 were further characterized by X-ray diffraction analysis where the almost planar NSN rare-earth metal unit is C s (or pseudo C s ) symmetry with the two alkyl groups arranging on both sides and a coordinated THF against it. Upon activation with [PhMe 2 NH][B(C 6 F 5 ) 4 ] and Al i Bu 3 , all these complexes exhibited high 3,4-regioselectivity (ranging from 91% to >99%) for the polymerization of isoprene. Moreover, the excellent isospecific selectivity up to mmmm > 99% have been achieved with complexes 1 depending on the electronics of the sulfur substituents to give crystalline polyisoprene with the highest T m (170 °C) reported to date. The NPN-bidentate β-imidophosphonamide ligated rare-earth metal complexes provide both high syndio-and iso-3,4-selectivities (3,4 > 99%, rr = 66%, mmmm = 96%) depending on the frameworks, steric environment and geometry of the ligands. The regio-and stereo-selective mechanisms proceeded in these systems were explicated by DFT simulation.

An efficient artificial light-harvesting system with two-step sequential energy transfer has been successfully constructed based on supramolecular self-assembly.

Nylon 11 (PA11)/clay nanocomposites have been prepared by melt-blending, followed by melt-extrusion through a capillary. Transmission electron microscopy shows that the exfoliated clay morphology is dominant for low nanofiller content, while the intercalated one is prevailing for high filler loading. Melt rheological properties of PA11 nanocomposites have been studied in both linear and nonlinear viscoelastic response regions. In the linear regime, the nanocomposites exhibit much higher storage modulus (GЈ) and loss modulus (GЉ) values than neat PA11. The values of GЈ and GЉ increase steadily with clay loading at low concentrations, while the GЈ and GЉ for the sample with 5 wt % clay show an inverse dependence and lie between the modulus values of the samples with 1 and 2 wt % of clay. This is attributed to the alignment/orientation of nanoclay platelets in the intercalated nanocomposite induced by capillary extrusion. In the nonlinear regime, the nanocomposites show increased shear viscosities when compared with the neat resin. The dependence of the shear viscosity on clay loading has analogous trend to that of GЈ and GЉ. Finally, a comparison has been made between the complex and steady viscosities to verify the applicability of the empirical CoxMerz rule.

With the aid of CTAB amphiphile, water-phase artificial light-harvesting systems were fabricated as nanoparticles by the self-assembly of two low-molecular-weight organic molecules: a UPy-functionalized TPE derivative 1 with both supramolecular...

The synergistic effect of two anticancer drugs can significantly overcome the multidrug resistance of tumor cells and improve the drug bioavailability. Herein, two different anticancer drugs, camptothecin and chlorambucil, are successfully connected together by a disulfide linkage to get a novel drug-drug conjugated prodrug (G). Using water-soluble pillar[6]arene (WP6) as a host molecule, a supramolecular host-guest complex WP6⊃G is formed, which can further self-assemble into supramolecular vesicles in aqueous solution. In the specific microenvironment of cancer cells, the disulfide linkage is destroyed and the two anticancer drugs can be released efficiently to achieve a better synergistic effect than a single anticancer drug. Notably, these prodrug nanocarriers can not only effectively kill the cancer cells but also obviously reduce the undesirable side effects on normal cells.