Search

The influence of aggregation patterns on intersystem crossing (ISC) was investigated by constructing homologous monomers (S-TPA-PI and L-TPA-PI) and their homologous dimers (S-2TPA-2PI and L-2TPA-2PI).

A review on performance optimization and application of ferroelectric thin film materials.

A (001)-oriented NaNbO3–LaCoO3:Mn thin film with enhanced ferroelectric properties was successfully deposited on a SrRuO3-buffered LaAlO3 substrate by radiofrequency magnetron sputtering. This epitaxial thin film modified by element doping shows a tetragonal ferroelectric structure and large remanent polarization (31 μC cm−2) with high Curie temperature (450 °C). The polarization fatigue tests demonstrate an improved fatigue resistance due to the reduced oxygen vacancies by element doping. Further X-ray absorption spectra experiments found that the split energy between Nb t2g and eg orbitals is reduced and the hybridization between transition metal d-O 2p is strengthened, leading to enhanced ferroelectric polarization.

Stimulus-induced in situ forming hydrogels possess the characteristics of easy management and minimal invasiveness via simple injection at target sites with a liquid and easy forming bulk gels. In the present study, a photoreactive monomer, N’-(2-nitrobenzyl)-N-acryloyl glycinamide (NBNAGA) was introduced to modify polyacrylamide (PAM) hydrogel preparation with stimuli responsiveness. Firstly, poly(acrylamide-co-N’-(2-nitrobenzyl)-N-acryloyl glycinamide), P(AM-co-NBNAGA), copolymer solution was prepared via reversible addition fragmentation chain transfer (RAFT) polymerization using the monomers mixture of AM, NBNAGA, and N,N’- methylene bis-acrylamide (BIS). The obtained polymer solution with viscous, transparent, and flowable appearance contained weak single hydrogen bonding and slight chemical crosslinking in a microscopic perspective. Secondly, without further purification, after irradiation using UV light at 365 nm, poly(acrylamide-co-N-acryloyl glycinamide) (P(AM-co-NAGA)) hydrogel conveniently in situ formed due to the cleavage of o-nitrobenzyl groups and the corresponding emergency of dual hydrogen bonding among “uncaged” dual amide moieties. P(AM-co-NAGA) hydrogel depicted both favorable temperature sensitivity and self-healing properties, then the heating induced in vitro release profiles of doxorubicin (DOX) was analyzed.

Novel organic/inorganic hybrid star polymer was prepared dually crosslinked within inner-core via divinylbenzene (DVB) and outer-surface via octafunctional polyhedral oligomeric silsesquioxane (POSS). Core cross-linked star polymers bearing dialkynyl-terminated polystyrene arms, (dialkynyl-PS)n-CCL, were synthesized at first by the atom transfer radical polymerization (ATRP) of DVB using α,α-dialkynyl-terminated PS macroinitiator, followed by the subsequent fractionation. Under high dilution conditions, (dialkynyl-PS)n-CCL was subjected to surface cross-linking with octa(3-azidopropyl) polyhedral oligomeric silsesquioxane, POSS-(N3)8, via click reaction, affording POSS-functionalized hybrid polymer doubly cross-linked within core and surface regions, SCL-(PS)n-CCL. FT-IR, 1H NMR, GPC, and elemental analysis results revealed that on average, the obtained hybrid polymer possesses a cross-linked PDVB inner core, ∼14 linear PS arms (the Mw per arm of 5.1 kDa), and ∼4-5 POSS moieties at outer surface. Differential scanning calorimetry (DSC) thermograms and thermogravimetric analysis (TGA) revealed that after surface cross-linking the thermal stability of SCL-(PS)n-CCL is considerably improved. This work provides a proof-of-concept example for the preparation of dually cross-linked hybrid star polymer, which represents a novel category of organic/inorganic composite materials with unique chain architectures.

Unveiling the synergism among multiple organelles for fully exploring the mysteries of the cell has drawn more and more attention. Herein, we developed two two-photon fluorescent bioprobes (Lyso-TA and Mito-QA), of which the conformational change triggered an "off-on" fluorescent response. Lyso-TA can real-time monitor the fusion and movement of lysosomes as well as unveil the mitophagy process with the engagement of lysosomes. Mito-QA was transformed from Lyso-TA by one-step ambient temperature reaction, visualizing the dysfunctional mitochondria through a shift from mitochondria to nucleoli. With superior two-photon absorption cross section, good biocompatibility, and greater penetration depth, two small bioprobes were both applied in in vivo bioimaging of brain tissues and zebrafish.

A series of compounds (W1-W8) based on triphenylamine with -C=N- or -NH- group, were designed and studied by fluorescence emission spectra and DFT/TDDFT calculations. Probes W1-W4 were selectively leveraged to sensitively detect glutathione by two distinct reaction mechanisms, thereinto, W1-W2 featured a convenient detection for glutathione using hydrolysis and W3-W4 utilized displacement to probe glutathione possessing sensitivity and practicability. Compound W5-W8 here provided an avenue for understanding structure-property relationship. Taken considerations for toxicity and biocompatibility together, W1-W4 showed great advance for endogenously and exogenously imaging GSH in living cells.

Two novel similar structural coumarin-based fluorescent compounds L1 and L2 employing ether oxygen chain and 2 – pyridine unit had been prepared to explore the effect of structural adjustment on property. The prepared L2 through slightly adjusting structure of L1 exhibited the prominent fluorescence responses to Hg2+ and Cu2+ in H2O, which could monitor the corresponding metals ion in mitochondria of Hela cells, but L1 only recognized Hg2+ through turn-on fluorescence response in CH3OH/H2O, fluorescence co-localization studies illustrated that the L1 mainly located at lysosome. The recognition mechanism had been established by 1H NMR titration, Job’s plot, MAlDI-TOF mass spectrometry and single crystal structure. Bio-imaging experiments revealed that L1 and L2 could qualitatively monitor Hg2+ or Cu2+ in Hela cells and mouse kidney tissues.

A novel conjugated polymer PProDOT(MeEO)2 based on dioxythiophene with symmetric double ethoxymethyl pendant groups was successfully synthesized through electrochemical polymerization. The polymer film exhibits reversible electrochromism switching between broadly absorbing bluish black neutral state (− 0.1 V) and transmissive sky blue oxidized state (0.7 V). The symmetric double short-chain ethoxymethyl substitution pattern was utilized to realize the broadly absorbing bluish black neutral state of the polymer film. The electrochemical, spectroelectrochemical, and electrochromic switching properties of the polymer film were studied in detail.

A novel conjugated polymer PProDOTCBDEM based on propylenedioxythiophene (ProDOT) with diethyl malonate (DEM) pendant group and a cyclobutane spacer between ProDOT and DEM was successfully synthesized through electrochemical polymerization. The polymer film exhibits reversible electrochromism switching between navy neutral state (− 0.1 V) and transmissive oxidized state (0.7 V). The symmetric double short chain ester substitution pattern was utilized to realize the navy color of the polymer film. The electrochemistry, spectroelectrochemistry and electrochromic switching properties of the polymer film were studied in detail.

The synthesis and electrochromic properties of a novel regiosymmetric polymer based on 3,4-ethylenedioxythiophene, poly(2,3-bis(bromomethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine) (PEDOT(MeBr)2) were highlighted. The monomer was electrochemically polymerized via repetitive cycling between 0 and 1.8 V in lithium perchlorate (LiClO4)–acetonitrile (ACN) electrolytic medium. The corresponding polymer was characterized by FTIR spectra, scanning electron microscopy, cyclic voltammetry, UV–Vis-NIR spectroscopy and colorimetry. It features a reversible redox process and demonstrates a stable blue-to-transmissive electrochromic behavior with very low driving potentials (−0.1 and 0.65 V). Additionally the polymer film exhibits enhanced optical contrast (60% at 669 nm) and improved coloration efficiency (183.1 cm2/C at 100% full contrast during bleaching process) which are higher than those of PEDOT, a relatively longer response time compared with PEDOT and reasonable redox stability.

Novel triphenylamine (TPA)-based derivative L, which shows strong affinity for SiO32− and fluorometric detection of Cu2+ over other anions or cations, has been synthesized by simple steps. The experimental results displayed that derivative L has a remarkable sensitivity towards SiO32− by producing separately dispersed and modified silica nanoparticles (NPs) with an average size of 377 nm in acetonitrile solution. Moreover, L also displayed obvious selectivity to Cu2+via 29-fold fluorescence intensity enhancement with a blue shift of 33 nm due to the formation of a 2 : 1 complex at room temperature. In addition, the probe could map the distribution of intracellular SiO32− or Cu2+ in live cells by fluorescence confocal microscopy.

The construction of intelligent supramolecular nanocarriers has received much attention for their potential application in chemotherapy. Herein, we report the successful design and synthesis of a photoreactive monomer, N′-(2-nitrobenzyl)-N-acryloyl glycinamide (NBNAGA). Using a poly(ethylene glycol) (PEG)-based macro-RAFT agent, the amphiphilic diblock copolymer (BCP), PEG-b-PNBNAGA, was prepared through a reversible addition–fragmentation chain-transfer (RAFT) polymerization. Then, photoresponsive polymeric micelles (PMs) were fabricated with the hydrophilic PEG shielding coronas and hydrophobic PNBNAGA inner cores via the self-assembly of PEG-b-PNBNAGA BCPs. Upon 365 nm UV light irradiation, the o-nitrobenzyl groups in the micellar cores were removed with freshly formed amide moieties. 1. Combined with the original amide moieties dual hydrogen bond interactions in the side chains came into being, subsequently changing the PMs’ cores from hydrophobic to hydrophilic. Thus, the photo-induced dual hydrogen-bonding complex rather than a hydrophobic interaction assembly with inviable nanostructures was achieved, which gave rise to the first stage of doxorubicin (DOX) release. During the second period, the noncovalent cross-linked PMs underwent further structural disintegration upon heating with dissociation of the dual hydrogen bonds, resulting in the sequential DOX release. In other words, periodic drug release was successfully accomplished via a photoirradiation-induced mechanism modification of micellar cores formation and then by subsequent heating-induced hydrogen-bonding complex disruption, thus indicating its promise for use in therapeutics synergistic delivery in severe disease therapy.

Multiferroic materials draw more and more attention due to their potential applications in novel multifunctional instruments and devices. In nanocomposite thin films, the ferroelectric and magnetic orders can be manipulated by orientation and strain, which will affect the multiferroics. In this letter, we reported an epitaxial PbTiO3:-Fe2O3 composite thin film with 20 nm thickness, which was fabricated on (111)-oriented Nb:SrTiO3 substrate by radio frequency magnetron sputtering method. The nanocomposite film presents both ferroelectric (Pr ≈ 19 µC cm−2) and ferromagnetic (Ms ≈ 25 emu cc−1) properties at room temperature. The combination of PbTiO3 and -Fe2O3 distinctly reduced the magnetic coercive field of the -Fe2O3. Piezoresponse force microscopy demonstrated that the composite film possessed excellent uniformity and surface quality, which is significant to the application of multifunctional precision devices.

Conventional probes are often difficult to observe apoptosis and autophagy at the same time. Herein, a series of small molecule multifunctional probes (L1-L6) were developed conveniently. Among, probes L1-L2 located in the mitochondria and L3 located in the lysosome in live cells, probes L4-L5 targeting mitochondria and L6 targeting lysosomes in living cells were further developed as a comparison. The experiment results of cells apoptosis showed that L1-L3 could immigrate to nucleolus, but L4-L6 did not due to the increased lipotropy. Significantly, fluorescence microscopy images showed that L2 could accumulate in the autophagic vacuoles when autophagy was activated, which gradually fused with lysosomes to form autolysosomes with increase of autophagy vacuoles. The results provided a beneficial reference for further preparing multifunctional fluorescence probe for monitoring apoptosis and autophagy.

In the title compound, C17H19NO5, the morpholine ring adopts a chair conformation with the exocyclic N—C bond in an equatorial orientation. In the crystal, the molecules are linked by C—H...O and weak aromatic π–π stacking interactions, thereby generating a layered structure.

The title compound, C21H15N3O3, features an essentially planar molecule (r.m.s. deviation for all non-H atoms = 0.090 Å). An intramolecular C—H...N hydrogen bond occurs. In the crystal, the molecules are connected by C—H...N and C—H...O hydrogen bonds into layers parallel to (102).

Pyrophosphate (PPi) played crucial roles in various fundamental physiological processes. Herein, a two-photon absorption (TPA) "On-Off-On" type benzoxazole-based fluorescence probe BN was designed and synthesized, which detected PPi through Cu2+ displacing method in situ system in aqueous medium. The on-off-on process of BN recognizing PPi was verified by mass spectra and theoretical calculations, which was successfully applied in TPA cells imaging.

Three new anthryl Schiff base derivatives containing a similar molecular structure were synthesized through a simple method and their fluorescent properties were investigated in detail. Among these, compound 1 displayed an aggregation-induced emission (AIE) feature, 2 exhibited an aggregation-induced emission enhancement (AIEE) property, while 3 showed aggregation-caused quenching (ACQ) behavior. Single-crystal structure and theoretical calculation analysis show that the larger conjugation and the existence of multiple intra- and intermolecular interactions restricts the intramolecular vibration and rotation, which benefit the emission in the condensed state, while the tight dimer structure and intramolecular torsional motion induce fluorescence quenching. Moreover, compound 2 can be utilized as fluorescence on–off type sensor for Cu2+ in methanol–H2O (4/1, v/v, pH 7.2) HEPES buffer solution, as well as fluorescence off–on type sensor for Zn2+ in pure methanol solution. The 2 : 1 ligand-to-metal coordination pattern of the 2-Cu2+ and 2-Zn2+ were calculated through a Job's plot, and were further confirmed by X-ray crystal structures of complexes 2-CuBr2 and 2-ZnCl2. In addition, 2 also exhibits a piezofluorochromic characteristic.

In this paper, a novel easily available off–on fluorescent and colorimetric probe based on triphenylamine-isophorone-based Schiff base was synthesized and characterized by 1 H NMR, 13 C NMR, MS, FTIR. A comprehensive analysis on recognition ability of the target product toward metal ions was conducted by ultraviolet absorption and fluorescence emission spectra. Results showed that the target product was stable in pH 5–9, and had effectively selective and sensitive recognition toward Cu 2+ in acetonitrile, with no significant interference of other competitive metal ions. The limit of detection of this probe was calculated as low as 1.568 × 10 −6 M for Cu 2+ .

A coumarin-based colorimetric and fluorescence off–on probe (L) containing diaminomaleonitrile unit was synthesized. The probe can detect Cu2+ in acetonitrile solution with high sensitivity and selectivity. The single crystal structures of probe L and L-Cu2+ complex showed that Cu2+ played dual roles of coordination center and catalyst that catalyzed the ring-closing of diaminomaleonitrile moiety in the recognition process based on addition reaction. Moreover, this probe can successfully detect Cu2+ in living cells.

Three new complexes, [CdL2(CH3COO)2(H2O)2] (I), CdL2Br2 (II), CdL2I2 (III), have been successfully synthesized by self-assembly of corresponding metal salts with (E)-2-(3-(4-(1H-imidazole-1-yl)styryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile (L). The structures of the complexes were determined by single crystal X-ray diffraction analysis (CIF file CCDC nos. 957831 (I), 957792 (II), 957832 (III)). In complex I, central metal is six-coordinated and the crystal packing shows a 3D supramolecular framework. Complexes II and III display the similar 2D supramolecular structures in which the central metals are four-coordination. The luminescent properties were investigated.

Self-assembly of a multidentate ligand containing pyridyl groups, namely, 6-phenyl-4-(4′-[2-(2-naphthalene)ethenyl]phenyl)-2,2′-bipyridine (L) with corresponding zinc(II) salts, affords a series of coordination complexes, ZnLI2 (I), [ZnLCl2]2 · 2CH2Cl2 (II), ZnLBr2 (III). Complexes I and II were characterized by single crystal X-ray diffraction (CIF files CCDC nos. 943273 (I), 944798 (II)). In complex I, the π-π stacking and C-H⋯π interactions based on the pyridyl group constructed the 1D and 2D structures. While in complex II, various weak interactions including hydrogen bonds (C-H⋯Cl and C-H⋯π) played significant roles in the final supramolecular structures. The luminescent properties of ligand and the complexes were investigated. The results reveal that different anions have shown a great influence on both the molecular structures and luminescent properties of the complexes.

Two new Zn(II) coordination complexes [ZnL2(SCN)2] (I) and [ZnL2Cl2] (II) have been pre-pared by self-assembly of corresponding metal salts with (E)-2-(3-(4-(1H-imidazole-1-yl)styryl)-5,5-dimethylcyclohexo-2-enylidene) malononitrile (L) and characterized by IR spectrum, elemental analysis and single-crystal X-ray diffraction. Complexes I and II are two-dimensional (2D) networks with different topology structures. The luminescence properties were investigated.

Two novel soluble chemosensors (L1, L2) modified by aza-crown ether groups have been synthesized by one-step facile reaction. The chemosensors were fully characterized by IR, 1H NMR, 13C NMR and MS spectra. The recognition abilities of two sensors with a range of metal ions were evaluated. The results showed that L1 was a specialized sensor for Cu2+ and L2 was a multi-functional sensor being able to recognize Al3+ and Cr3+ via two different optical behaviors, which demonstrated the subtle structural changes of sensors can have a remarkable effect on recognizing metal ions.

Two novel 6-phenyl-2,2′-bipyridine derivatives based on aza-crown ether groups were synthesized and characterized, one of which was characterized by single crystal X-ray diffraction determination. Their linear photophysical properties were systematically investigated in various solvents. The nonlinear photophysical properties were investigated by two-photon induced fluorescence method. Both dyes exhibited large two-photon absorption cross-section (δ2PA). The cytotoxicity of the dyes was evaluated in HepG2 cell line to assess the potential application for biomedical imaging. Two-photon fluorescence microscopy (TPFM) imaging of two dyes in HepG2 cell line was demonstrated, which indicated that introduction of the hydrophilic aza-crown ether facilitates biological compatibility of dyes.

By self-assembly of (E)-2-(3-(4-(1H-imidazol-1-yl)styryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile (L(1)) and (E)-2-(3-(4-(1H-1,2,4-triazol-1-yl)styryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile (L(2)) with silver(I) salts, eight new complexes, namely AgL(1)2ClO4 (1), AgL(1)2NO3 (2), [AgL(1)2NO3]·C6H6 (3), [AgL(1)2OOCCF3]·C6H6 (4), [AgL(1)2PF6]·C6H6 (5), AgL(2)2NO3 (6), [AgL(2)OOCCF3]2 (7) and AgL(2)2PF6 (8), are presented along with an analysis of their structural features. The structures are built up through the combination of coordination bonds, Ag···π, Ag···F (or O), hydrogen bonding, and π···π stacking interactions to generate new supramolecular architectures. We observed the formation of two-dimensional coordination polymers for complex 7. Solvent benzene molecules and anions are dispersed in the supramolecular structure and play a vital role in building the supramolecular structures of the complexes. The nonlinear optical (NLO) properties of the complexes were investigated using the Z-scan technique and complexes 1, 2, 3, 4 and 7 show obviously nonlinear absorption compared with ligands (L(1) and L(2)).

Three new Schiff base derivatives possessing vagarious blue aggregation-induced emission (AIE) characteristics in tetrahydrofuran (THF)–water were synthesized. Their photophysical properties in solution, aqueous suspension, film and crystalline states, along with their relationships, were comparatively investigated. The crystallographic data for dye 1 and dye 3 indicated that the existence of multiple intermolecular hydrogen bonding interactions restricted intramolecular vibration and rotation. Moreover, the sizes and growth processes of particles with different water fractions were studied using a scanning electron microscope (SEM) and dynamic light scattering (DLS). The results showed that the small homogeneous particles, assembled in an ordered fashion with appropriate water contents, exhibited distinct AIE behavior. Moreover, in a THF–H2O (4 : 1, v/v) solution of HEPES (20 mM) buffer, dye 2 showed fluorescence turn-on sensing towards Cr3+ and Al3+via chelation enhanced fluorescence (CHEF). The 2 : 1 stoichiometries of the sensor complexes (dye 2–Cr3+ and dye 2–Al3+) were calculated from Job plots based on fluorescence titrations.

A new Schiff-base family containing [4-(1H-benzimidazole-2-yl)-phenyl]-bis-(4-ethoxy-phenyl)-amine has been synthesized through a condensation reaction. All the derivatives possess properties of aggregation-induced and crystallization-enhanced emission (AIE and CEE), which show time-dependent characteristics at a concentration of 10 μM and are studied in detail by scanning electron microscope (SEM) and transmission electron microscope (TEM). Different aggregation forms and the growth of crystals of the compounds, could be responsible for the notably different degrees of fluorescence enhancement.

Two ligands, 2-{5,5-dimethyl-3-[2-(pyridin-3-yl)-ethenyl]cyclohex-2-enylidene}propanedinitrile (L1) and 2-{5,5-dimethyl-3-[2-(pyridin-2-yl)-ethenyl]cyclohex-2-enylidene}propanedinitrile (L2), were synthesized. By reaction of mercury thiocyanate with L1 and L2, respectively, coordination polymers [Hg(L1)(μ1,3-SCN)2]n (1), [Hg(L1)2(μ1,3-SCN)2]n (2), and [Hg(L2)(μ1,3-SCN)(SCN)]n (3) with different structures and topologies were obtained. In 1, the thiocyanate shows μ1,3-SCN bridging coordination, and adjacent Hg(II) ions are bridged by two μ1,3-SCN ions to form an infinite chain with the remaining position of five-coordinate Hg(II) occupied by L1. In 2, the thiocyanate has the same coordination as 1. However, Hg(II) has octahedral coordination with two L1 involved in coordination. An unusual feature of 3 is the presence of two types of thiocyanates, one has a S-terminal ligand and the other has a μ1,3-SCN bridge. The mercury(II) in 3 is four-coordinated by L2 and three thiocyanates. Luminescent properties an...

Eight triphenylamine (TPA)-based Schiff bases that exhibit different aggregation-induced emission (AIE) or aggregation-caused quenching (ACQ) behavior in tetrahydrofuran (THF)/water mixtures have been synthesized and characterized. The photophysical properties in solution, aqueous suspension, film, and the crystalline state along with their relationships were comparatively investigated. The single-crystal structures of 1-8 indicate that compact π···π stacking or excimers induce fluorescence quenching of 1, 2, 5, and 7. However, the existence of J aggregates or multiple intra- and intermolecular interactions restrict the intramolecular vibration and rotation, enabling compounds 3, 4, 6, and 8 to exhibit good AIE character. The size and growth process of particles with different water fractions were studied using scanning electron microscopy, which demonstrated that smaller uniformly dispersed nanoparticles in the THF/water mixtures favor fluorescence emission. The above results suggest that the combined effects of multiple forces caused by structural variation have a great influence on their molecular packing, electronic structure, and aggregation-induced fluorescence properties. In addition, piezofluorochromic experiments verified the potential applications of 4 and 6.

A series of new cadmium complexes (dyes 1–5) were obtained by assembly of the donor–bridge–acceptor (D–π–A)-type ligand (L: 4′-(4-[4-(imidazole)styryl]phenyl) 2,2′ : 6′,2″-terpyridine) with CdX2 (X=Cl, Br, I, NCS, ClO4), in which dye 3 was characterized by single crystal X-ray diffraction. Various weak interactions, including hydrogen bonds (C–H⋯N, C–H⋯X) and π–π interactions, played significant roles in the final topological structures. Linear and non-linear optical properties of ligand and the complexes were investigated. The two-photon absorption cross-section of these complexes are larger than that of ligand with maximum values of 577 GM (dye 1), 242 GM (dye 2), 171 GM (dye 3), 326 GM (dye 4), and 215 GM (dye 5) in N,N-dimethylformamide.

A new series of D–π–A type two-photon absorption (2PA) dyes (1–4) based on imidazo[4,5-f]1,10-phenanthroline have been synthesized and their photophysical properties have been systematically investigated. These dyes showed obvious positive solvatochromic effects mainly due to intramolecular charge transfer (ICT). The two-photon absorption (2PA) cross-section values measured by two-photon excited fluorescence (TPEF) were determined to be 1232 GM and 4752 GM for dye 3 and dye 4, while dyes 1 and 2 do not display 2PA activity. These results demonstrate that their 2PA cross section values (σ) increase with increasing donor/acceptor (D/A) strength of the corresponding molecule. The results also imply that the replacement of the tetrazol group with the aza-crown-ether group results in an opposite charge transfer direction, which has been verified by density functional theory (DFT) calculations. In addition, a two-photon fluorescence cell imaging experiment proved the suitability of dye 3 for this potential application .

By using a solvothermal reaction in mixed solvent of ethylenediamine and ethylene glycol, nanoparticle-assembled sheet-like CuInSe 2 with hierarchically mesoporous structures were successfully fabricated with the absence of any template or structure-directing agent. The as-synthesized products were characterized by XRD, EDX, FESEM, TEM, HRTEM, BET nitrogen adsorption and NIR absorption spectrum. The possible formation mechanism was simply discussed. The size of mesopores is hierarchically distributed in the range of 2–30 nm and the specific surface area was estimated to be 10.15 m 2 /g. The value of band gap (E g ) was calculated to be 1.00 eV based on its NIR absorption spectrum.

In the title compound, C18H12N4O2, which has a delocalizedD—π—Aelectronic structure, the dihedral angles between the central benzene ring and the planes of the pendant imidazole and nitrobenzene rings are 37.65 (9) and 4.96 (7)°, respectively. In the centrosymmetric crystal structure, molecules are linked by weak C—H...O interactions, generating [001]C(6) chains.

Stormwater treatment by lamellar and conventional clarification, with and without flocculant addition, was investigated in Toronto, Ontario, using a pilot-scale rectangular clarifier vessel with removable lamellar plates. During the 2001 to 2003 field seasons, 76 stormwater runoff events were characterized with respect to flow and quality, and further investigated for stormwater treatment. Most stormwater constituent concentrations at this site exceeded those for the U.S. NURP median urban site. A cationic polymeric flocculant dosed at 4 mg/L, with lamellar clarification, provided the best results with a total suspended solids (TSS) removal of 83% at total vessel surface loads up to 36 m/h. The clarification processes produced a concentrated sludge, which was strongly polluted by heavy metals and would require special disposal procedures.

Soil covers are widely used in mine waste and landfill applications to protect the environment. For an effective soil cover, the infiltration and oxygen barrier must have a low hydraulic conductivity and also maintain a high degree of saturation. Soil water evaporation significantly affects water content, and as a result the degree of saturation of the soil. Therefore, knowledge of the rate of evaporation at the soil–atmosphere interface is required to estimate the water content of candidate cover soils. Clayey soil is commonly used, either separately as a single cover or in various combinations with other soils as a layered cover system. In this study, water flow through a single clayey till cover and a layered soil cover were modeled using a coupled liquid flow, vapor diffusion and heat transfer finite-element model (SoilCover). The layered soil cover studied was a typical mine-waste soil cover intended to control oxygen diffusion and infiltration in a temperate climate and consisted of three layers: coarse sand and fine sand as upper and lower capillary barriers, respectively, and clayey till as an infiltration and oxygen barrier. The water level was located at the bottom of the cover. Evaporation and drainage predicted by the model reasonably agreed with experimental results and showed that the clayey till would be an effective oxygen barrier in sulfide-bearing mine waste covers, for which a very low oxygen flux is desired in order to achieve environmental protection. The results emphasize the need to have evaporation and drainage barriers above and below clay barriers designed to retain moisture. Further analysis using SoilCover showed that coarse sand would perform better than either fine sand or silt as a protective top layer over a clayey till barrier.

Experimental measurement and analytical methods were performed to study water flow through four different cover soils: clayey till, silt, coarse sand and fine sand. The upward and downward water fluxes (i.e. evaporation and drainage) were measured in the laboratory under different water table conditions. Both experimental and analytical results indicated that downward water flow (drainage) significantly affected upward water flow (evaporation) during changes in the water table elevation. Deepening water table elevation decreased evaporation in the sands and to a lesser extent in the silt, by promoting gravity-driven drainage and hence limiting water supply to the soil surface. Evaporation and drainage in the fine-textured clayey till did not change significantly as the water table dropped from the soil surface to 1 m below the soil column. The results suggest that the clayey till would be an effective oxygen barrier in sulfide-bearing mine waste covers, while the sands would be effective evaporation and drainage barriers for the till. The experimental results showed that the air entry value and hydraulic conductivity of the soil are critical parameters controlling drainage and evaporation in soils under different water table conditions. The study emphasizes the need to have evaporation and drainage barriers above and below a soil layer intended to maintain high water saturation under adverse environmental conditions, such as high evaporation and a fluctuating water table.

Fibrous nanoaggregates of a new benzoxazole-based derivative have been reported. This derivative exhibits not only H-aggregates but also strong yellow fluorescence, which is different from the traditional understanding of H-aggregates.

The reduced viscosity of poly(ethylene glycol) in solutions containing a certain concentration of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) was measured. It has been found that the Huggins coefficient kH and the intrinsic viscosity [η] of polymer solution are very sensitive to the concentration of surfactants, CAOT, in solution. If CAOT is less than CMC, the critical micelle concentration of AOT, kH decreases and [η] increases rapidly with CAOT. On the other hand, if CAOT is greater than CMC, kH increases and [η] decreases rapidly with CAOT. The experimental results indicate that the inter- and intra-molecular association of poly(ethylene glycol) in solution is greatly associated with AOT interacted with polymer chain.

A series of new isophorone derivatives (1-5), incorporating the heterocyclic ring or aza-crown-ether group, with large Stokes shifts (140 nm), have been synthesized and characterized. 1-4 display aggregation-induced emission behaviors, while dye 5 is highly emissive in solution but quenched in the solid state. It was found that the tuning of emission color of the isophorone-based compounds in the solid state could be conveniently accomplished by changing the terminal substituent group. The photophysical properties in solution, aqueous suspension, and crystalline state, along with their relationships, are comparatively investigated. Crystallographic data of 1-4 indicate that the existence of multiple intermolecular hydrogen bonding interactions between the adjacent molecules restricts the intramolecular vibration and rotation and enables compounds 1-4 to emit intensely in the solid state. The size and growth processes of particles with different water fractions were studied using a scanning electron microscope, indicating that smaller globular nanoparticles in aqueous suspension are in favor of fluorescence emissions. The above results suggest that substituent groups have a great influence on their molecular packing, electronic structure, and aggregation-induced emission properties. In addition, fluorescence cell imaging experiment proved the potential application of 5.

Five triphenylamine containing benzimidazole derivatives (a1–a5) with different D/A groups (D and A stand for donor and acceptor, respectively), conjugation length or configuration were designed and synthesized. The one- and two-photon spectroscopic properties of these molecules were studied. All of these compounds have amazing fluorescence quantum yields in the range of 0.39–0.61. Besides, for a1–a5, the λem (emission maximum wavelength of one- and two-photons) are only dominated by the D/A groups, and the conjugation length is irrelevant, implying that the molecular rotation is in the excited-state. To better explain this phenomenon, the structure–property relationships of a1–a5, especially the molecular rotation in the excited-state, have been discussed in detail, and were identified by density functional theory calculations. Furthermore, four azo-heterocycle containing benzimidazole derivatives, which have weak electron-donating ability, were synthesized and discussed as a comparison. Finally, considering their optical action, cytotoxicity and solubility, a1, a2 and a4 were chosen for bio-imaging. The results show that the small molecule a2 is the best candidate for one-photon excited fluorescence and two-photon excited fluorescence imaging.