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Superior photoswitchable fluorescent polymer nanoparticles (PFPNs) are highly desirable for photo-rewritable data storage and ultrahigh-resolution bioimaging. Herein, 2-(3′,3′-dimethyl-6-nitrospiro[chromene-2,2′-indolin]-1′-yl)ethyl 2-(((dodecylthio)-carbonothioyl)thio)-2-methylpropanoate (SPTTC), a novel photochromic spiropyran-based reversible addition–fragmentation chain transfer (RAFT) reagent, and 5-dimethylaminonaphthalene-N-allyl-1-sulfonamide (DNS), the energy-level matched green fluorescent dye, were firstly synthesized. Then, they are used as donor and acceptor of the designed fluorescence resonance energy transfer (FRET) system to help fabricate superior dual-color PFPNs via a simple one-pot RAFT miniemulsion method. Thanks to its multiple merits such as the photochromic property, improved miscibility, and the ability to control polymerization rate, not only did the designed SPTTC provide the PFPNs with superior photoswitchable fluorescence properties such as high energy transfer efficiency (up to 91%), high dual-color contrast (green and red), rapid photoresponsiveness (2–4 min) and outstanding photoreversibility upon irradiation with UV and visible light, but it also endowed PFPNs with controllable molecular weight and narrow polydispersity index (PDI), excellent cell membrane permeability and long-term fluorescence stability. Moreover, the as-prepared PFPNs were successfully used for rewritable fluorescence patterning and intracellular dual-color imaging due to its prominent properties.

A microporous acylamide-functionalized MOF with a 2-fold interpenetrated and methyl decorated framework (HNUST-4) has been designed and synthesized from [Cu2(COO)4] motifs and a C2-symmetric acylamide-linking tetracarboxylate, which exhibits good water stability, permanent porosity as well as high and selective CO2 uptake at ambient temperature.

A highly porous 4,4-paddlewheel-connected NbO-type metal-organic framework (HNUST-2, HNUST represents Hunan University of Science and Technology) has been designed and synthesized by self-assembling [Cu₂(COO)₄] SBUs with a nanosized tetracarboxylate ligand prolonged by alkyne groups, 5,5'-(naphthalene-1,4-diylbis(ethyne-2,1-diyl))diisophthalic acid (H₄NDED). HNUST-2 exhibits high structural stability, a porous non-interpenetration framework with open metal sites and excellent gas-uptake capacity. This MOF material possesses a high BET surface area of 2366 m² g⁻¹, a large unsaturated excess and total H₂ uptake of 4.57 wt% and 5. 20 wt% at 20 bar and 77 K, respectively. Meanwhile, HNUST-2 also exhibits an excellent adsorption capacity for CO₂ (18.07 mmol g⁻¹ at 20 bar and 298 K) and CH₄ (85.6 cm³ cm⁻³ at 20 bar and 298 K) with a high selectivity for CO₂ over N₂ (22.9) and CH₄ (4.9) at 298 K.

A new expanded microporous NbO-type metal–organic framework [Cu2(BDPT4−)]n with inserted acylamide groups has been designed and synthesized, which shows both a large CO2-uptake capacity (156.4 cm3 g−1 at 1 bar) and a high selectivity for CO2 over N2 (39.8) and CH4 (7.2) at 273 K.

In the present study, we report on the fabrication of novel amphiphilic reversible photoswitchable fluorescent nanoparticles by a facile one-pot miniemulsion polymerization using a biocompatible polymerizable nonionic surfactant, ω-methoxy poly(ethylene oxide) undecyl α-methacrylate (PEO-R-MA-40), in which spiropyran-linked methacrylate (SPMA) and the energy level well-matched fluorescent dyes: fluorescein-based, vinylic crosslinking monomer (fluorescein-O,O-bis-propene (FBP)) were covalently incorporated into polymeric matrix during the polymerization process. Under the alternative irradiation of UV and visible light, the fluorescent emission of FBP dye in nanoparticles can be reversibly modulated by cyclical transformation of spiropyran moieties' structure on the basis of intra-particle FRET process between FBP and merocyanine (MC) state of spiropyran. The as-prepared fluorescent nanoparticles display high dye load, as well as controllable amount and ratio of the two dyes because of covalent linkage between dye molecules and the particle. Moreover, the observed FRET efficiencies (66.3–98.5%) can be facilely tuned by controlling the amount (ratio) of the two chromophores. Overall, significant features of these novel amphiphilic reversible photoswitchable fluorescent nanoparticles include higher biocompatibility and photostability, relatively fast photoresponsivity and better photoreversibility as compared to some previous reported systems, which are promising for biological, optical fields and so on.

To understand the substitution effects of 4-(pyridin-2-yl)pyrimidine (pprd) on the coordination reaction equilibria, the interactions between a series of the pprd-like ligands and [OV(O(2))(2)(H(2)O)](-) or [OV(O(2))(2)(HOD)](-) or [OV(O(2))(2)(D(2)O)](-) (bpV) have been explored by a combination of multinuclear ((1)H, (13)C, and (51)V) magnetic resonance, heteronuclear single quantum coherence (HSQC) and variable temperature NMR in a 0.15 mol L(-1) NaCl D(2)O solution that mimics physiological conditions. The direct NMR data are reported for the first time. Competitive coordination interactions result in a series of new hepta-coordinated peroxidovanadate species [OV(O(2))(2)LL'](-) (LL' = pprd-like chelating ligands). The equilibrium constants for the products between bpV and the pprd-like ligands show that the relative affinity of the ligands is pprd ≈ 2-NH(2)-pprd2-Me-pprd2-Et-pprd4-(6-methylpyridin-2-yl)pyrimidine (abbr. 6'-Me-pprd). When the ligand is pprd, a pair of isomers (Isomer A and B) are observed in aqueous solution, which are attributed to the different types of coordination modes between the metal and the ligands, while the crystal structure of NH(4)[OV(O(2))(2)(pprd)]·2H(2)O has the same coordination structure as Isomer A. For substituted pprd ligands, however, only one type of structure (Isomer A or B ) is observed in solution. These results demonstrate that, when the aromatic ring has a substitution group, both the steric effect (from the alkyl) and hydrogen bonding (from the amine) can affect the coordination reaction equilibrium to prevent the appearance of either Isomer B in solution for the ligands 2-Me-pprd, 2-NH(2)-pprd, 2-Et-pprd, or Isomer A in solution for 6'-Me-pprd.