Allylic alcohols and allylic amines were directly utilized in a Pd-catalyzed hydrogen-bond-activated allylic amination under mild reaction conditions in the absence of any additives. The cooperative action of a Pd-catalyst and a hydrogen-bonding solvent is most likely responsible for its high reactivity. The catalytic system is compatible with a variety of functional groups and can be used to prepare a wide range of linear allylic amines in good to excellent yields. Furthermore, this methodology can be easily applied to the one-step synthesis of two drugs, cinnarizine and naftifine, on a gram scale.

•A low-cost UVI indication card based on a photochromic coating was prepared.•A colorimetric analysis system was built as an Android application on smartphone.•A portable convenient method for real-time measurement of UVI was developed.The present study offers a simple and real-time method to measure the ultraviolet index (UVI) via a photochromic UVI indication card and a colorimetric analysis system built on the smartphone. A photochromic Ormosil (Organically Modified Silicates) coating doped by the spirooxazine dye (SO-G) was prepared. The coating, with the broad absorption at 450–650 nm, exhibited as a grey tone on its appearance under ultraviolet irradiation. The spectrokinetics of the SO-G doped Ormosil coating was investigated by monitoring the changes of absorption values at 495 nm with time. During its photochromic process, the equilibrium time for both photostationary states were less than 20 s. Tests of photochromic reversibility showed the reproducibility of at least 90 cycles. The UVI indication card was fabricated using the photochromic Ormosil coating and a printed standard depth scale was used for the UVI sensing strip to evaluate the instantaneous ultraviolet index. The relationship between the relative grayscales (Gy*) and the ultraviolet index was studied, and the linearity was obtained. The colorimetric analysis system including acquisition and processing of the image for colorimetric analysis was then built on the smartphone. By applying the UVI indication card as well as the Android application developed which brought the user experiences of visualization, convenience and participation, users can monitor fluctuating of the ultraviolet indexes all day long. This method is advantageous for application in smartphones used by nonprofessional consumers and is valuable to be investigated in-depth for the commercial importance.

Naphthopyran dyes are one important family of photochromic compounds, and the understanding of the effects of internal and external factors on their functions is crucial to their development. In this study, the intramolecular hydrogen bond and host materials have been demonstrated to be essential to their applications. A novel N-(4-chlorophenyl)-3,3-diphenyl-3H-benzo[f]chromene-5-carboxamide (NPase) dye is designed and synthesized based on the condensation reaction of 1,1-diphenylprop-2-yn-1-ol and N-(4-chlorophenyl)-3-hydroxynaphthalene-2-carboxamide in an acidic solution. Both the X-ray analysis of the NPase single crystal and theoretical calculation are used to investigate the molecular configuration and optical property. After the introduction of an intramolecular hydrogen bond by the substitute in the dye, an unusual coplanar structure is theoretically proposed and experimentally confirmed, which affects the tautomerization energy and bathochromic-shift in absorption characteristics greatly. Our results also confirm that the flexible segment of polymethylsiloxane (PDMS) in the host hybrid coating (PMS–PDMS) materials can accelerate the spectrokinetics of NPase which indicates a faster conversion process.

A novel photochromic dye (NPB)-doped ormosil matrix coating with fast spectrokinetics was studied as functional materials for smart windows. First, the NPB was modified into a reactive silylated dye (NPB-Si) by a silane coupling agent. Then, the NPB-Si was hydrolyzed and copolycondensed with methyl triethoxysilane to form the ormosil (NPB-PMS) via the sol–gel method. Finally, the photochromic ormosil matrix coating on the substrate was obtained by the following spin-coating process. Upon the activation by the UV irradiation, the ormosil coating displayed the characteristic dual absorption peaks at 504 and 628 nm, which indicated as a valuable neutral tone. The dual absorption is due to the existence of photoisomers. On the basis of the theoretical calculation, the trans–cis photoisomers displayed the longer wavelengths in visible region than those of trans–trans ones, which was due to the less coplanarity. The kinetics studies of coloration and decoloration of NPB-PMS indicated an accelerated conversion process than that of NPB-doped polystyrene coating. The improved spectrokinetics of NPB-PMS coating is ascribed to the nanoscaled cavities observed in their surfaces, which offered enough space for molecular rotation during the photochromism. Our results also demonstrated that the NPB-PMS coating had much better solvent wash-off resistance than the physically doped coating.

A novel molecular probe (P2) sensing polynuclear hydrolyzed aluminum by chelation-enhanced fluorescence was described, which was prepared from 1,1'-(1,4-phenylene)bis(7-methyl-1,3,5-octanetrione) and 2-aminomethylpyridine. P2 showed a strong fluorescence response to Al(III) when excited by the optimized wavelength of 400 nm and the λmax,em at 505 nm indicated a hypsochromic shift of 11 nm to that of free P2, but Cu(II) was observed to quench the fluorescence intensity to nearly zero. The P2–Al(III) complex indicated the best fluorescence response at a pH near 7 and there might be a relevance to the amphoteric property of the aluminum hydroxide. The emission intensity at 505 nm continued to increase until the mole ratio of [Al(III)]/[P2] reached a value of 13 and no stoichiometry was observed during the process, which implied that the sensing target of the P2 probe was not the free aluminum ion but the polynuclear hydrolyzed aluminum. The binuclear hydrolyzed aluminum compounds were selected as model target molecules to simulate the energy-minimized structure of the P2–Al(III) complex to confirm the CHEF mechanism. The enhanced fluorescent images of HeLa cells incubated with 1 μM P2 and 5 μM Al(III) were obtained.Highlights► A novel molecular probe based on CHEF mechanism was designed and prepared. ► Probe showed a strong fluorescent response to Al(III) selectively. ► Quantum chemistry simulation was used to illustrate the mechanism of CHEF. ► Sensing target Al(III) showed to be the polynuclear hydrolyzed aluminum. ► Enhanced fluorescent images of HeLa cells using P2 were obtained.

Allylic alcohols and allylic amines were directly utilized in a Pd-catalyzed hydrogen-bond-activated allylic amination under mild reaction conditions in the absence of any additives. The cooperative action of a Pd-catalyst and a hydrogen-bonding solvent is most likely responsible for its high reactivity. The catalytic system is compatible with a variety of functional groups and can be used to prepare a wide range of linear allylic amines in good to excellent yields. Furthermore, this methodology can be easily applied to the one-step synthesis of two drugs, cinnarizine and naftifine, on a gram scale.