Synthesis of Novel Ladder Bis-Silicon-Bridged <i>p</i>-Terphenyls

The tetralithiation reaction of 2,2‘,5‘,2‘ ‘-tetrabromo-p-terphenyl followed by a double silacyclization produces bis-silicon-bridged p-terphenyls. On the basis of this convenient method, a series of new ladder-type p-terphenyl derivatives have been synthesized. Their crystal structures and photophysical properties are described

Synthesis of Novel Ladder Bis-Silicon-Bridged <i>p</i>-Terphenyls

The tetralithiation reaction of 2,2‘,5‘,2‘ ‘-tetrabromo-p-terphenyl followed by a double silacyclization produces bis-silicon-bridged p-terphenyls. On the basis of this convenient method, a series of new ladder-type p-terphenyl derivatives have been synthesized. Their crystal structures and photophysical properties are described

Synthesis of Novel Ladder Bis-Silicon-Bridged <i>p</i>-Terphenyls

The tetralithiation reaction of 2,2‘,5‘,2‘ ‘-tetrabromo-p-terphenyl followed by a double silacyclization produces bis-silicon-bridged p-terphenyls. On the basis of this convenient method, a series of new ladder-type p-terphenyl derivatives have been synthesized. Their crystal structures and photophysical properties are described

New Organogels Based on an Anthracene Derivative with One Urea Group and Its Photodimer: Fluorescence Enhancement after Gelation

By coupling the features of anthracene and urea, a new low-molecular-weight gelator (LMWG, 1) with anthracene and urea moieties was designed and synthesized. A nontransparent gel of LMWG 1 in 1,2-dichloroethane was formed and characterized. Of particular interest is the observation of significant fluorescence enhancement after gelation, which is referred as to gelation-induced enhanced fluorescence emission. UV light irradiation of the THF solution of LMWG 1 yielded a photodimer with the h-t conformation. The photodimer can gel several organic solvents, including cyclohexane, n-hexane, and n-heptane. It should be mentioned that the gel based on the photodimer is rather stable. Our studies indicate that neither the gel phase based on LMWG 1 nor that based on the photodimer can be transformed to the solution by respective UV light irradiation or visible light irradiation/heating

Effect of Polyvinyl Alcohol on Ice Formation in the Presence of a Liquid/Solid Interface

Tuning ice formation is of great importance in biological systems and some technological applications. Many synthetic polymers have been shown to affect ice formation, in particular, polyvinyl alcohol (PVA). However, the experimental observations of the effect of PVA on ice formation are still conflicting. Here, we introduced colloidal silica (CS) as the model liquid/solid interface and studied the effect of PVA on ice formation in detail. The results showed that either PVA or CS promoted ice formation, whereas the mixture of these two (CS–PVA) prevented ice formation (antifreezing). Using quantitative analysis based on classical nucleation theory, we revealed that the main contribution came from the kinetic factor <i>J</i>₀ rather than the energy barrier factor Γ. Combined with the PVA adsorption behavior on CS particles, it is strongly suggested that the adsorption of PVA at the interface has significantly reduced ice nucleation, which thus may provide new ideas for developing antifreezing agents

Highly Selective Ratiometric Fluorescence Determination of Ag⁺ Based on a Molecular Motif with One Pyrene and Two Adenine Moieties

A highly selective ratiometric fluorescence sensor for Ag+ was developed with a molecular motif containing one pyrene and two adenine moieties

Highly Regiospecific Synthetic Approach to Monobay-Functionalized Perylene Bisimide and Di(perylene bisimide)

Monobay-dichlorinated perylene bisimide and diperylene bisimide have been regiospecifically synthesized from tetrachlorinated perylene bisimide in different copper-mediated reaction conditions, thus opening a new avenue to their monobay-functionalization

Highly Regiospecific Synthetic Approach to Monobay-Functionalized Perylene Bisimide and Di(perylene bisimide)

Monobay-dichlorinated perylene bisimide and diperylene bisimide have been regiospecifically synthesized from tetrachlorinated perylene bisimide in different copper-mediated reaction conditions, thus opening a new avenue to their monobay-functionalization

Molecular docking study of main components from different plants and ntMGAM.

<p>p<i>K</i>_d, the negative logarithm (base 10) of the dissociation constant.</p

Characterizing the Adsorption of Poly(vinyl alcohol) on Colloidal Silica with Aggregation-Induced Emission Fluorophore

The adsorption of polymer on colloidal particle has significant influence on colloid structure and dynamics. Here we introduce a new method to monitor the adsorption in situ, based on the different emission behavior of aggregation-induced emission (AIE) luminogen in different micro environments. Poly­(vinyl alcohol) (PVA) and colloidal silica (CS) were used as a model system. It was found that AIE molecules exhibited extremely low fluorescence intensity in water and PVA solution, while their emission efficiency was enhanced when adsorbed on CS, and became significantly boosted when PVA was adsorbed on CS at the same time. The fluorescence intensity increases with the amount of added PVA and reaches a saturation point, which is earlier than that obtained by the well-established solvent relaxation NMR method, due to their different sensitivities for adsorption segments in specific conformation. This new method is advantageous in quick response, where the measurement can be finished within 2 min, while others usually take hours. Therefore, it is expected that this new method may be used to monitor the dynamical adsorption process of polymer on colloidal particles