Supramolecular Sequential Light-Harvesting Systems for Constructing White LED Device and Latent Fingerprint Imaging.

The fabrication of supramolecular light-harvesting systems (LHS) with sequential energy transfer is of significance in utilizing light energy. In this study, we report the non-covalent self-assembly of a sequential LHS by pillar[5]arene-based host-guest interaction in water and its applications in white light-emitting diode (LED) device and latent fingerprint imaging. The host-guest complex WP5 ⊃ ${ \supset }$ G self-assembles into nanoparticles in water and shows enhanced aggregation-induced emission (AIE) effect. The nanoparticles can be further used to construct sequential LHS with fluorescent dyes 4,7-di(2-thienyl)-benzo[2,1,3]thiadiazole (DBT) and sulforhodamine 101 (SR101). Impressively, the system shows white-light emission when the molar ratio of WP5 ⊃ ${ \supset }$ G/DBT/SR101 is 1100/2/16. The material can be coated on a LED bulb to achieve white-light emission. In addition, the sequential LHS exhibit multicolor fluorescence including red emission, which have been successfully applied to high-resolution imaging of latent fingerprints. Therefore, we demonstrated a general strategy for the construction of sequential LHS in water based on macrocyclic host-guest interaction and explored its multi-functional applications in white-light LED device and imaging of latent fingerprints, which will promote future development and application of supramolecular LHSs.

Fluorescent Nanoassemblies in Water Exhibiting Tunable LCST Behavior and Responsive Light Harvesting Ability.

Responsive fluorescent nanomaterials have been received considerable attention in recent years. In this work, a bola-type amphiphilic molecule, CSO, was synthesized which contains a hydrophobic cyanostilbene core and hydrophilic oligo(ethylene glycol) (OEG) coils at both sides. The cyanostilbene group is aggregation-induced emission (AIE) active, while the OEG coils are thermo-responsive. As a result, the CSO molecules can self-assemble into blue-fluorescent nanoassemblies with lower critical solution temperature (LCST) behavior in aqueous media. It is noteworthy that the LCST behavior can be reversibly regulated with changes in concentration and the introduction of K+ . Intriguingly, fluorescence of CSO assembly shows a blue-shift upon heating. Finally, by employing CSO as a light capturing antenna and energy donor, an artificial light harvesting system with tunable emission and thermo-responsive characteristics was fabricated. This study not only demonstrates an integrated approach to create responsive fluorescent nanomaterials, but also shows great potential for producing luminescent materials and mimicking photosynthesis in nature.

Supramolecular vesicles based on pillar[n]arenes: design, construction, and applications.

Supramolecular vesicles have attracted considerable attention due to their advantages of facile construction, high-cargo-loading capacity, and good biocompatibility. Pillar[n]arenes are a unique family of supramolecular macrocycles, exhibiting excellent features and broad applications due to their intrinsic topology and high functionality. In the past decade, the construction of pillar[n]arene-based supramolecular vesicles has been continuously attempted and developed rapidly. In this review, we mainly summarize the significant advancements of such supramolecular vesicles in the last three years. By showing some representative examples, the design strategies, construction methods, and potential applications of these dynamic nanocarriers are discussed in detail. In particular, the responsiveness of such vesicles to various external stimuli and their applications in drug delivery are highlighted. The outstanding performance of pillar[n]arene-based supramolecular vesicles would definitely enrich the family of supramolecular vesicles and promote the development of dynamic supramolecular materials.

Low power consumption thermo-optic switch formed by an integrated processing method.

In this paper, an integrated processing method was demonstrated to fabricate the polymer-based thermo-optic (TO) switch with low power consumption. The characteristic parameters of the switch were carefully designed and simulated. The air trench structure was exploited to reduce the power consumption, which can be formed with the waveguide simultaneously by the integrated processing method. Moreover, the introduced polymer/silica hybrid waveguide structure can also improve the response time of the device. A typical fabricated switch presented a low switching power of 5.2 mW. The measured switching rise time and fall time are 192.2 and 201.1 µs, respectively.

Tunable Copper-Catalyzed Reaction of C60 with 2-Ethoxycarbonylacetamides and Subsequent BF3·Et2O-Mediated Isomerization of the Generated Dihydrofuran-Fused Fullerenes to Fulleropyrrolidinones.

A tunable copper-catalyzed reaction of C60 with 2-ethoxycarbonylacetamides using air as the oxidant has been explored, which selectively affords methanofullerenes (2) and dihydrofuran-fused fullerenes (3) under the CuI/DMAP and CuCl/NMI catalytic systems, respectively. Furthermore, the generated dihydrofuran-fused fullerenes could be transformed to fulleropyrrolidinones (4 and 5) upon treatment with BF3·Et2O.

Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives.

A number of upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate to good enantioselectivities up to 94% ee were achieved. Detailed experiments clearly showed that the upper rim-functionalized hydrophobic calixarene scaffold played an important role in cooperation with the catalytic center to the good reactivities and enantioselectivities.

Copper-Catalyzed Functionalizations of C60 with Amino Alcohols.

CuI-catalyzed diverse functionalizations of C60 with amino alcohols with aerobic oxygen as the sole oxidant have been explored. For 2-/3-amino alcohols, an aminooxygenation reaction occurs to generate fulleromorpholine and fullerooxazepane derivatives. When a tethered furan ring exists, a further intramolecular [4 + 2] reaction with the neighboring double bond occurs to furnish the cis-1 products. In the case of 4-/5-amino alcohols, methanofullerenes linking with cyclic amides are obtained through cyclic enamine intermediates.

Chiral exploration of 6,12-diphenyldibenzo[b,f][1,5]diazocine with stable conformation.

A first optical resolution of 6,12-diphenyldibenzo[b,f][1,5]diazocine with stable boat conformation was achieved by chiral supercritical fluid chromatography (SFC). The absolute configurations of enantiomers were first assigned and determined by X-ray crystal structure based on CIP-rules. The high optical rotation and circular dichroism spectrum were well explained by electronic helix theory. Owing to the high stabilization of boat conformation, the chiral configuration could be maintained at very high temperature, more than 200 °C, which was proved by Density Functional Theory calculations.

The Cs2CO3-Catalyzed Reaction of 2-Oxindoles with Enones for the Preparation of Indolin-3-Ones and Their Further Transformation.

The Cs2CO3-catalyzed reaction of 2-oxindoles with enones affords 2,2-disubstituted indolin-3-ones through domino "Michael addition-oxidation-ring-cleavage-C-N coupling" process. O2 acts as the sole oxidant to accomplish the oxidative process. The indolin-3-ones can be further transformed to pyridazine, azirdine-fused 3-oxindoles, 4-quinolone derivatives easily.

Cu(OAc)2-Mediated Reaction of C60 with Ureas for the Preparation of Fulleroimidazolidinones.

The Cu(OAc)2-mediated intermolecular diamination reaction of C60 with ureas allows the concise and efficient preparation of fulleroimidazolidinones involving the cleavage of two N-H bonds and formation of two C-N bonds. Both dialkylated and diarylated fulleroimidazolidinones can be synthesized using this method.

2-Oxindole Acts as a Synthon of 2-Aminobenzoyl Anion in the K2CO3-Catalyzed Reaction with Enones: Preparation of 1,4-Diketones Bearing an Amino Group and Their Further Transformations.

A convenient approach for the synthesis of 1,4-diketones bearing an amino group has been developed through the K2CO3-catalyzed reaction of 2-oxindoles with enones with the assistance of atmospheric O2 via sequential Michael addition-oxidation-ring-cleavage process. The further intramolecular reaction leads to the formation of benzoazepinone, quinoline, and 3-oxindole derivatives.

Reaction of C60 with Inactive Secondary Amines and Aldehydes and the Cu(OAc)2-Promoted Regioselective Intramolecular C-H Functionalization of the Generated Fulleropyrrolidines.

The thermal reaction of C60 with aromatic aldehydes and inactive secondary amines for the stereoselective synthesis of trans-1,2,5-trisubstituted fulleropyrrolidines has been developed. Moreover, when an o-hydroxyl group was located at the phenyl ring of the generated fulleropyrrolidines, the Cu(OAc)2-promoted regioselective intramolecular C-O coupling reaction occurred to generate unique tricycle-fused fullerene derivatives.

Improved performance of thermal-optic switch using polymer/silica hybrid and air trench waveguide structures.

By exploiting the polymer/silica hybrid and the air trench waveguide structures, we demonstrate a new type of low-power consuming and high-speed thermal-optic (TO) switch. Such a design provides an effective means to shorten the switching time of the TO switches, as well as to reduce the power consumption at the same time. This TO switch operated with less than 150 µs of switching time via a polymer/silica hybrid waveguide structure. Meanwhile, the power consumption was reduced to be 3.4 mW by introducing the air trench structure.

Cu(OAc)2-promoted reaction of [60]fullerene with primary amines or diamines.

The Cu(OAc)2-promoted reaction of C60 with easily available primary amines allows the concise preparation of aziridinofullerenes. Both alkyl and aryl amines are suitable in this reaction. Moreover, the Cu(OAc)2-promoted reaction of C60 with diamines affords C60-fused cyclic 1,2-diaminated fullerenes.

650-nm 1 × 2 polymeric thermo-optic switch with low power consumption.

In this paper, a low-power 1 × 2 polymeric thermo-optic switch operating at the polymer optical fiber low-loss window of 650 nm was studied. The characteristic parameters of the switch were carefully designed and simulated. The fabrication was done by using standard semiconductor fabrication techniques such as spin-coating, photolithography, and dry etching. The device was fabricated based on poly(methyl methacrylate) (PMMA)-based materials with the Mach-Zehnder interferometer (MZI) structure. The device shows an extinction ratio of over 23.4 dB at 650 nm with a very low-power consumption of 5.3 mW. The measured switching rise time and fall time are 464.4 and 448.0 µs, respectively.

Lewis base-catalyzed reaction of aziridinofullerene with ureas for the preparation of fulleroimidazolidinones.

The Lewis base-catalyzed double nucleophilic substitution reaction of N-tosylaziridinofullerene with various ureas allows the easy preparation of fulleroimidazolidinones with a high tolerance for functional groups. Alkyl-substituted ureas show better reactivity than aryl-substituted ureas.

BF3·Et2O- or DMAP-catalyzed double nucleophilic substitution reaction of aziridinofullerenes with sulfamides or amidines.

BF3·Et2O-catalyzed double nucleophilic substitution reaction of N-tosylaziridinofullerene with sulfamides has been exploited for the easy preparation of cyclic sulfamide-fused fullerene derivatives. Moreover, the Lewis base catalyzed double amination of N-tosylaziridinofullerene, with amidines as the diamine source, is demonstrated for the first time. The present methods provide new routes to cyclic 1,2-diaminated [60]fullerenes.

BF3·Et2O-catalyzed formal [3 + 2] reaction of aziridinofullerenes with carbonyl compounds.

The BF3·Et2O-catalyzed formal [3 + 2] reaction of aziridinofullerenes with various carbonyl compounds for the easy preparation of fullerooxazolidines has been developed. Moreover, the reaction of aziridinofullerene with ethyl formate affords the simplest fullerooxazole without substituent.

2-[2-(4-Methyl-piperazin-1-yl)eth-yl]iso-indoline-1,3-dione.

In the title compound, C15H19N3O2, the piperazine ring adopts a chair conformation, with its N-C bonds in pseudo-equatorial orientations. The dihedral angle between the C atoms of the piperazine ring and the phthalamide ring system (r.m.s. deviaiton = 0.008 Å) is 89.30 (8)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, generating a three-dimensional network and aromatic π-π inter-actions also occur [centroid-centroid distances = 3.556 (1)-3.716 (1) Å].

Re/Mg bimetallic tandem catalysis for [4+2] annulation of benzamides and alkynes via C-H/N-H functionalization.

A rhenium-magnesium cocatalyzed [4+2] annulation of benzamides and alkynes via C-H/N-H functionalization is described. The reaction features a divergent and high level of diastereoselectivities, which are readily switchable by subtle tuning of reaction conditions. Thus, a wide range of both cis- and trans-3,4-dihydroisoquinolinones is expediently synthesized in a highly atom-economical manner. Moreover, mechanistic studies unraveled a tandem mode of action between rhenium and magnesium in the catalytic cycles.