Correction: Multiple pH responsive zwitterionic micelles for stealth delivery of anticancer drugs.

[This corrects the article DOI: 10.1039/C6RA11645K.].

Spirobifluorene-based hole-transporting materials for RGB OLEDs with high efficiency and low efficiency roll-off.

In this work, we designed and synthesized three spirobifluorene (SBF)-based hole-transporting materials (HTMs) by incorporating the di-4-tolylamino group at different positions of the SBF skeleton. These materials demonstrate excellent thermal stability with thermal decomposition temperatures ( ) up to 506 °C and outstanding morphological stability with a glass transition temperature ( ) exceeding 145 °C. The -linkage mode between the conjugated skeleton and functional groups in the molecular structure results in electronic decoupling, giving these 3,6-substituted SBFs higher triplet energies ( ) compared to 2,7-substituted SBFs.

Crafting 1,4-diaryl spirobifluorene hosts in OLEDs interannular C-H arylation: synergistic effects of molecular linearity and orthogonality.

In this work, we present a design concept of introducing linear structures into the orthogonal configuration of 9,9'-spirobifluorene (SBF), aiming to enhance carrier mobilities while maintaining high triplet energies ( ), which are two critical parameters for optimizing host materials in organic light-emitting diodes (OLEDs). To validate our proposed design, four pivotal model molecules of 1,4-diaryl SBFs were synthesized interannular C-H arylation of bi(hetero)aryl-2-formaldehydes, a task challenging to accomplish using previous synthetic methodologies. The orthogonal configuration and the steric hindrance of SBF lead to high through the conjugation breaking at C1 and C4 positions, rendering 1,4-diaryl SBFs suitable as universal pure hydrocarbon (PHC) hosts for red, green, and blue (RGB) phosphorescent OLEDs (PhOLEDs).

Photoswitchable and long-lived seven-membered cyclic singlet diradicals for the bioorthogonal photoclick reaction.

Annularly 1,3-localized singlet diradicals are energetic and homolytic intermediates, but commonly too short-lived for widespread utilization. Herein, we describe a direct observation of a long-lived and seven-membered singlet diradical, oxepine-3,6-dione-2,7-diyl (OXPID), spectroscopic experiments and also theoretical evidence from computational studies, which is generated photo-induced ring-expansion of 2,3-diaryl-1,4-naphthoquinone epoxide (DNQO). The photo-generated OXPID reverts to the thermally stable σ-bonded DNQO with in the μs level, thus constituting a novel class of T-type molecular photoswitches with high light-energy conversion efficiency ( = 7.

Molecular engineering of locked alkyl aryl carbonyl-based thermally activated delayed fluorescence emitters a cascade C-H activation process.

While diaryl ketones have drawn tremendous attention for the assembly of carbonyl-based thermally activated delayed fluorescence (TADF) emitters, alkyl aryl ketones are almost ignored. In this work, an efficient rhodium-catalyzed cascade C-H activation process of alkyl aryl ketones with phenylboronic acids has been developed for the concise construction of the α,α-dialkyl/aryl phenanthrone skeleton, which unlocks an opportunity to rapidly assemble a library of structurally nontraditional locked alkyl aryl carbonyl-based TADF emitters. Molecular engineering indicates that the introduction of a donor on the A ring enables the emitters to exhibit better TADF properties than those with a donor on the B ring.

Simultaneously enhancing the crystallization rate and fire retardancy of poly(lactic acid) by using a novel bifunctional additive trimethylamine phenylphosphonate.

Simultaneously regulating the crystallizing and combustion behaviors of poly(lactic acid) (PLA) will be conducive to its further development in the fields of electronic appliances, automotive and rail transit materials. To achieve this goal, a novel bifunctional additive triethylamine phenylphosphonate (TEAP) was synthesized through acid-base neutralization reaction between trimethylamine and phenylphosphonic acid. When TEAP was added into PLA, the crystallization behaviors of PLA/TEAP assessed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM) suggested that TEAP acted as a nucleating agent and plasticizer for PLA, which effectively increased the crystallization rate of PLA.

Expanding the functionality of proteins with genetically encoded dibenzo[,][1,4,5]thiadiazepine: a photo-transducer for photo-click decoration.

Genetic incorporation of novel noncanonical amino acids (ncAAs) that are specialized for the photo-click reaction allows the precisely orthogonal and site-specific functionalization of proteins in living cells under photo-control. However, the development of a r̲ing-strain l̲oadable d̲ipolarophile (RILD) as a genetically encodable reporter for photo-click bioconjugation with spatiotemporal controllability is quite rare. Herein, we report the design and synthesis of a photo-switchable d̲ib̲enzo[,][1,4,5]t̲hiad̲iazepine-based a̲lanine (DBTDA) ncAA, together with the directed evolution of a pyrrolysyl-tRNA synthetase/tRNA pair (PylRS/tRNA), to encode the DBTDA into recombinant proteins as a RILD in living cells.

Hydrogen-bond super-amphiphile based drug delivery system: design, synthesis, and biological evaluation.

Drug delivery systems (DDSs) show great application prospects in tumor therapy. So far, physical encapsulation and covalent grafting were the two most common strategies for the construction of DDSs. However, physical encapsulation-based DDSs usually suffered from low drug loading capacity and poor stability, and covalent grafting-based DDSs might reduce the activity of original drug, which greatly limited their clinical application.

Element coding based accurate evaluation of CRISPR/Cas9 initial cleavage.

As a powerful gene editing tool, the kinetic mechanism of CRISPR/Cas9 has been the focus for its further application. Initial cleavage events as the first domino followed by nuclease end trimming significantly affect the final on-target rate. Here we propose EC-CRISPR, element coding CRISPR, an accurate evaluation platform for initial cleavage that directly characterizes the cleavage efficiency and breaking sites.

Molecular design of thermally activated delayed fluorescent emitters for narrowband orange-red OLEDs boosted by a cyano-functionalization strategy.

The establishment of a simple molecular design strategy to realize red-shifted emission while maintaining good color purity for multi-resonance induced thermally activated delayed fluorescent (MR-TADF) materials remains an appealing yet challenging task. Herein, we demonstrate that the attachment of a cyano (CN) functionality at the lowest unoccupied molecular orbital location of the MR-TADF skeleton can promote attractive red-shifted emission due to the exceptional electron-withdrawing capacity of the CN group, which represents the first example of orange-red MR-TADF emitters. Meanwhile, the linear CN group adopts a coplanar conformation with the MR-framework to restrict structure relaxation associated with rotation, which is beneficial to maintain a small full-width at half-maximum and thus a good color purity.

Trace mild acid-catalysed → isomerization of norbornene-fused stilbene derivatives: intelligent chiral molecular photoswitches with controllable self-recovery.

Stilbene derivatives have long been known to undergo "acid-catalyzed" → isomerization, where a strong mineral acid at high concentration is practically necessary. Such severe reaction conditions often cause undesired by-reactions and limit their potential application. Herein, we present a trace mild acid-catalyzed → isomerization found with stilbene derivatives fused with a norbornene moiety.

Molecular engineering enabling reversible transformation between helical and planar conformations by cyclization of alkynes.

Molecular engineering enabling reversible transformation between helical and planar conformations is described herein. Starting from easily available 2-(pyridin-2-yl)anilines and alkynes, a one-pot strategy is set up for the synthesis of aza[4]helicenes two successive rhodium-catalyzed C-H activation/cyclizations. Helical pyrrolophenanthridiziniums can be transformed into planar conformations through the cleavage of acidic pyrrole N-H, leading to turn-off fluorescence.

Regioselective addition/annulation of ferrocenyl thioamides with 1,3-diynes a sulfur-transfer rearrangement to construct extended π-conjugated ferrocenes with luminescent properties.

Herein a regioselective addition/annulation strategy of ferrocenyl (Fc) thioamides with alkynes to construct thienylferrocene (ThienylFc) structures, involving a rhodium-catalyzed C-H activation, an unusual C2-selective addition of 1,3-diyne, and an unexpected intramolecular sulfur-transfer rearrangement process is described. In this protocol, thioamide not only serves as a directing group to activate the -C-H bond of the ferrocene, but also as a sulfur source to form the thiophene ring. The resulting carboxylic ester group after sulfur transfer can act as a linkage to construct extended π-conjugated ferrocenes (OCTFc) with luminescent properties.

Build-up of double carbohelicenes using nitroarenes: dual role of the nitro functionality as an activating and leaving group.

The construction of double carbohelicenes is highly fascinating yet challenging work. Disclosed herein is a streamlined and simplified synthetic route to double carbohelicenes starting from nitroarenes through sequential nitro-activated -C-H arylation, denitrative alkenylation and intramolecular cyclodehydrogenation. In this synthetic strategy, the nitro group plays a dual role namely as a leaving group for the denitrative alkenylation and as an activating group for -C-H arylation, which is distinct from those of aryl halides in a conventional coupling reaction.

A methylation platform of unconventional inert aryl electrophiles: trimethylboroxine as a universal methylating reagent.

Methylation is one of the most fundamental conversions in medicinal and material chemistry. Extension of substrate types from aromatic halides to other unconventional aromatic electrophiles is a highly important yet challenging task in catalytic methylation. Disclosed herein is a series of transition metal-catalyzed methylations of unconventional inert aryl electrophiles using trimethylboroxine (TMB) as the methylating reagent.

Dandelion flower-like micelles.

Dandelion flower-like micelles (DFMs) were prepared by self-assembly of polycaprolactone (PCL) functionalized surface cross-linked micelles (SCMs). Upon reductive stimuli, the SCMs can be released from the DFMs by non-Brownian motion at an average speed of 19.09 μm s.

Construction of a luminescent sensor based on a lanthanide complex for the highly efficient detection of methyl parathion.

A highly sensitive and selective luminescent sensor for the detection of methyl parathion (MP) pesticide was described in this study. The target molecule HL was synthesized by modifying the structure of 4-hydroxybenzlidene imidazolinone (HBI) with nitrogen-containing heterocyclic 1,10-phenanthroline. In the presence of Eu, a HL-Eu complex was formed which could emit strong red fluorescence due to the removal of coordinated water molecules and an intramolecular energy transfer from HL to Eu.

A Col I and BCP ceramic bi-layer scaffold implant promotes regeneration in osteochondral defects.

Osteochondral defects occur in the superficial cartilage region, intermediate calcified cartilage, and subchondral bone. Due to the limited regenerative capacity and complex zonal structure, it is critically difficult to develop strategies for osteochondral defect repair that could meet clinical requirements. In this study, type I collagen (Col I) and BCP ceramics were used to fabricate a new bi-layer scaffold for regeneration in osteochondral defects.

Correction: A long-persistent phosphorescent chemosensor for the detection of TNP based on CaTiO:Pr@SiO photoluminescence materials.

[This corrects the article DOI: 10.1039/C8RA02665C.].

A long-persistent phosphorescent chemosensor for the detection of TNP based on CaTiO:Pr@SiO photoluminescence materials.

The detection of nitroaromatic explosives is important due to their strong explosive force and harmfulness in the environment, and for homeland security and public safety. Herein, a phosphorescence CaTiO:Pr@SiO nanosensor was successfully developed for the sensitive and selective detection of 2,4,6-trinitrophenol (TNP). The red-emitting phosphorescent chemosensor CaTiO:Pr@SiO possessed a long enough phosphorescence lifetime of 0.

and assessment of nanostructured porous biphasic calcium phosphate ceramics for promoting osteogenesis in an osteoporotic environment.

Treatment of bone defects in osteoporotic patients with bone substitutes is difficult, due to insufficient osseointegration. The development of appropriate biomaterials to solve the problem requires the assessment of the material performance in an osteoporotic environment, which is rarely investigated. Herein, nanostructured biphasic calcium phosphate (nBCP) ceramics were prepared the incorporation of hydroxyapatite nanoparticles (HANPs) into porous biphasic CaP (BCP) substrates, leading to an increase of over 500% in the specific surface area.

Preliminary identification of unicellular algal genus by using combined confocal resonance Raman spectroscopy with PCA and DPLS analysis.

The analysis of algae and dominant alga plays important roles in ecological and environmental fields since it can be used to forecast water bloom and control its potential deleterious effects. Herein, we combine in vivo confocal resonance Raman spectroscopy with multivariate analysis methods to preliminary identify the three algal genera in water blooms at unicellular scale. Statistical analysis of characteristic Raman peaks demonstrates that certain shifts and different normalized intensities, resulting from composition of different carotenoids, exist in Raman spectra of three algal cells.

Room-Temperature Coupling/Decarboxylation Reaction of α-Oxocarboxylates with α-Bromoketones: Solvent-Controlled Regioselectivity for 1,2- and 1,3-Diketones.

A transition-metal-free and room-temperature coupling/decarboxylation reaction between α-oxocarboxylates and α-bromoketones is reported herein. It represents the first mild and regioselective synthesis of either 1,2- or 1,3-diketones from the same starting materials. Notably, the regioselectivity is simply controlled by solvents.