Dipropionic Acid Research Articles

ROS sensitive micelles of carbon dioxide based amphiphilic polymer for delivery of avermectin

A novel amphiphilic polymer, methoxy polyethylene glycols (mPEG)-3, 3′-(propane-2, 2-diylbis (sulfanediyl)) dipropionic acid (TK)-poly (propylene oxide-co-carbon dioxide-co-allyl glycidyl ether) (PPAG) (mPEG2000-TK-PPAG), was successfully synthesized for delivery of avermectin (AVE). The chemical structure was characterized by FTIR. In aqueous medium, mPEG2000-TK-PPAG could self-assembled into micelles. The AVE loaded mPEG2000-TK-PPAG micelles showed a considerable drug-loading content of 19 %. The prepared micelles were spherical morphology with average hydrodynamic diameter 469.4 nm and zeta potential of around –33.6 mv. AVE was released slowly from the AVE loaded mPEG2000-TK-PPAG micelles in a neutral condition and was released rapidly under stimulation of reactive oxygen species (ROS). Therefore, this ROS responsive micelle formulation achieves target control of pests and provides an efficient micelle platform for green agriculture.

Effect of Tight Junction-Modulating FCIGRL-Modified Peptides on the Intestinal Absorption of Doxorubicin in Rats.

Doxorubicin is a potent chemotherapy drug, but its oral bioavailability is limited due to its low membrane permeability. Thus, absorption enhancers such as zonula occludens toxin and its six-mer fragment, FCIGRL, have been studied to address this issue. This study aimed to evaluate the effectiveness of four peptides (Pep1, Pep2, Pep3, and Pep4) derived from FCIGRL and investigate the changes in the absorption of doxorubicin, to propose an absorption enhancer for doxorubicin. Pep1 is a modified version of FCIGRL in which the hydroxyl group at the C-terminus is replaced with an amino group. Pep2 is a modified Pep1 in which cysteine is replaced with N3-substituted dipropionic acid. Pep3 and Pep4 are Pep2-modified homodimers. Pharmacokinetic analysis was performed in rats after the intraduodenal administration of doxorubicin solutions containing each FCIGRL-modified peptide and the stabilizer levan or benzalkonium chloride (BC). The results showed that Pep3 and Pep4 administered with levan each significantly increased the intestinal absorption of doxorubicin, as did Pep2 administered with levan/BC. In particular, 10 mg·kg-1 of Pep4 with levan significantly increased the area under the curve (AUC)0-240min of doxorubicin by 2.38-fold (p < 0.01) and the peak concentration (Cmax) by 3.30-fold (p < 0.01) compared to the control solution. The study findings indicate that Pep2, Pep3, and primarily Pep4 are novel absorption enhancers that can open tight junctions for doxorubicin, and the effectiveness of the peptides was directly affected by the presence of levan or levan/BC.

Quantum-chemistry-computing and experimental development of a new n-alkenyl amino propionic and imino di-propionic acids-based gum inhibitor for gasoline

We present the quantum mechanics-based understanding about the formation of gums deposits in order to design, and then carry out the experimental synthesis of a detergent-dispersant (DD) gasoline additive base n-alkenyl imino di-propionic acid, obtained in mixture with its precursor base n-alkenyl amino propionic acid, aimed both to inhibit gums deposits within internal-combustion engines and maintain in suspension gums inside gasoline. Density Functional Theory reveals the cohesion among gums agglomerates is mediated mainly through dispersion forces, that is, gums form supramolecular complexes; likewise, their affinity for oxidized metallic surfaces is predominantly due also to the dispersion forces, but intensified through the linking of the gums' oxygens by the exposed metallic-surface irons, which is quantum driven to maximize irons spin through completing the truncated oxygen octahedral coordination, so providing to the gums' adsorption a mixed chemisorption/physisorption character. Additionally, carbons from double bonds C=C or from aromatic rings, as well as aminic hydrogens, contribute by means of weak semicovalent bonds to the gums’ chemisorption too. We take advantage of this acquired knowledge to outline a superior coordination chemistry to that of gums for the above deposits inhibitor, lying on the capability to form either trinuclear-tridentate or binuclear-bidentate surface complexes, reinforced moreover by a six-membered chelate ring containing an iron cation. The additive was lab synthesized by means of an industrial-scale residues-less process, and characterized through 1H and 13C nuclear magnetic resonance along with infrared spectroscopy. The detergent performance, experimentally tested within the intake valve of a single-cylinder engine, shows that the DD additive inhibits up to 93.3% of the gums deposition.

Design and synthesis of new water-soluble dinuclear manganese(II) complexes as monosaccharide binding models

The present article describes the design, synthesis, physicochemical characterization and monosaccharide binding events of two new water-soluble dinuclear manganese(II) complexes [Mn2(phpda)(µ-Cl)]·2H2O (1) and [Mn2(phpda)(µ-OAc)]·2H2O (2) of carboxylate and pyridyl-functionalized multidentate ligand, H3phpda (H3phpda = N,N′-bis[2-pyridylmethyl]-2-hydroxy-1,3-propanediamine-N,N′-dipropionic acid). FTIR, UV–Vis, ESI-MS, microanalysis, molar conductivity, cyclic voltammetry and room-temperature magnetic data establish their compositions. Structural features of 1 and 2 obtained from theoretical calculations indicate a self-assembled and well-packed array with average Mn···Mn separation of 2.952 Å. Both 1 and 2 have been studied towards 1:1 binding interactions with biologically important monosaccharides, such as d-glucose, d-xylose and d-glucosamine by employing UV–Vis spectroscopy and DFT computation. The binding constant values of monosaccharide-bound manganese(II) complexes evaluated from UV–Vis titration data are 2.145 x 103 M−1, 2.156 x 103 M−1, 2.652 x 103 M−1, 1.388 x 103 M−1, 1.793 x 103 M−1 and 2.146 x 103 M−1 for 1/d-glucose, 1/d-xylose, 1/d-glucosamine, 2/d-glucose, 2/d-xylose and 2/d-glucosamine assemblies, respectively. The possible metal centers engaged in the binding events have been ascertained by calculating the Fukui functions (fk+) on the manganese sites, including HOMOs and LUMOs. A comparative assessment of sugar-binding properties, in particular, suggests that the order of binding ability of monosaccharides with 1 and 2 is found to be d-glucosamine > d-xylose > d-glucose.

Singlet oxygen‐responsive hyaluronate dot clusters for tumor therapy

AbstractIn this study, we developed nanoclusters that respond to singlet oxygen and can be adjusted in size to enhance the efficacy of tumor therapy. Specifically, we engineered nanoclusters, denoted as dHAc‐PSDA‐Ce6, through the covalent conjugation of hyaluronate dots (dHA) with 3,3‐(propane‐2,2‐diylbis(sulfanediyl))dipropionic acid (PSDA) as a cleavable crosslinker mediated by singlet oxygen, and chlorin e6 (Ce6) as a representative model drug for photodynamic therapy. The hyaluronic acid (HA) component within dHAc‐PSDA‐Ce6 was harnessed for the specific targeting of CD44 receptors that are overexpressed on tumor cells. Upon subjecting the vicinity of tumor cells to light irradiation, the PSDA crosslinker within dHAc‐PSDA‐Ce6 undergoes cleavage, likely facilitated by the singlet oxygen generated by Ce6. This cleavage process leads to the formation of dHA‐Ce6 molecules. We hypothesized that a nanocluster, circulating safely within the bloodstream, would undergo a transformation into individual dHA‐Ce6 molecules upon light irradiation at the localized tumor site. This transformation, in turn, enhances the photodynamic antitumor effect. Our in vitro investigations have demonstrated the remarkable efficacy of dHAc‐PSDA‐Ce6 in inducing tumor cell death upon light irradiation. Furthermore, our in vivo biodistribution studies have revealed the substantial accumulation of these nanoclusters within the tumor site. We anticipate that this singlet oxygen‐responsive nanocluster harbors substantial promise for enhancing tumor accumulation and fortifying the effectiveness of tumor eradication.

Multifunctional Chiral d10-Metal Coordination Polymers: Tunable Photoluminescence and Efficient Second-Harmonic Generation with Circular Dichroic Response.

A series of homochiral coordination polymers (HCPs), [M2(SIAP)2(bpy)2] [M(S)] and [M2(RIAP)2(bpy)2] [M(R)] (M = Zn or Cd, SIAP or RIAP = (S,S)- or (R,R)- 2,2'-(isophthaloylbis(azanediyl))di-propionic acid, bpy = 4,4'-bipyridine), is successfully synthesized through solvothermal reactions, self-assembling d10 metal cations, chiral dicarboxylic ligands, and π-conjugated bipyridyl ligands. The HCPs crystallize in the extremely rare triclinic chiral space group, P1, and present 3D framework structures attributed to the strong intermolecular interactions, such as hydrogen bonds and π-π stacking. Due to the unique crystal structures, the title compounds reveal efficient photoluminescence emission across a broad visible range, with significant brightness and color tuning by varying the excitation wavelength. Moreover, they exhibit efficient phase-matched second-harmonic generation (SHG) with very high laser-induced damage thresholds, essential for high-power nonlinear optical (NLO) applications. Intriguingly, the title compounds exhibit a measurable contrast in the SHG response under right- and left-handed circularly polarized excitation, thereby providing a unique case of SHG circular dichroism from the chiral centers of SIAP2- or RIAP2- ligand packed in the noncentrosymmetric environment. These exceptional attributes position these HCPs as promising candidates for multifunctional materials, with potential applications ranging from NLO devices to tailored luminescent systems with polarization control.

Exceptionally water-soluble [CuII2] complexes for investigating monosaccharide-metal ion interactions

The design, synthesis and characterization of two new dinuclear copper(II) complexes [Cu2(phpda)(µ-Cl)]·2H2O (1) and [Cu2(phpda)(µ-NO3)]·2H2O (2) (H3phpda = N,N′ -bis[2-pyridylmethyl]-2‑hydroxy-1,3-propanediamine-N,N′-dipropionic acid) as carbohydrate binding models have been reported. The FTIR, UV–Vis, ESI-MS, microanalysis and molar conductance data have been utilized to characterize the synthesized complexes. The structures of 1 and 2 have been established by density functional theory (DFT) calculations that exhibit a self-aggregated closely packed arrangement with average inter-metallic Cu···Cu separation of 3.2484 Å. In aqueous alkaline media, both complexes have been studied for their binding interactions with biologically important monosaccharides, d-glucose and d-glucosamine by employing UV–Vis spectroscopy and DFT calculations. The binding-assisted steady decrease of absorbances of 1 and 2 accompanied by a significant red/blue shift of absorption maxima of the complexes upon UV–Vis titration of 1 and 2 with d-glucose and d-glucosamine has been observed, suggesting 1:1 complex/monosaccharide interactions. Evaluation of binding constant values of monosaccharide-bound copper(II) complexes has been accomplished by utilizing UV–Vis titration data, and the values are found to be 2.145 × 103 M−1, 2.652 × 103 M−1, 1.388 × 103 M−1 and 1.793 × 103 M−1 for 1/D-glucose, 1/D-glucosamine, 2/D-glucose and 2/D-glucosamine assemblies, respectively. Fukui functions (fk+) on the copper sites, including HOMO and LUMO in both complexes have been obtained from DFT calculations to understand the likely copper sites involved in the binding events with monosaccharides. However, a comparative assessment of their binding constant values showed that d-glucosamine interacts with 1 and 2 more preferentially than d-glucose.

Low Molecular Weight Hydrogel for Wound Healing.

Octadecylazanediyl dipropionic acid (C18ADPA) is a zwitterionic amphiphile with a dendritic headgroup. C18ADPA self-assembles to lamellar networks, which encompasses water and forms a low-molecular-weight hydrogel (LMWG). In this study, we use the C18ADPA hydrogel as a drug carrier for the in vivo delivery of a copper salt for wound healing in a mouse model. A structural transition was observed based on cryo-scanning electron microscope (cryo-SEM) images after drug loading. The C18ADPA hydrogel, which had a layered structure, transformed into a self-assembled fibrillar network (SAFiN). The mechanical strength of the LMWG has always been an important issue in its applications. However, due to the structural transition, both the storage and loss moduli increased. In vivo tests showed that wound closure was faster after applying the hydrogel formulation compared with the Vaseline formulation. For the first time, we have also provided histological evidence of these effects on skin tissue. The hydrogel formulation exhibited clear advantages in regenerating tissue structure over traditional delivery formulations.

Biomimetic Amino Acid Functionalized Phenazine Flow Batteries with Long Lifetime at Near-Neutral pH.

Aqueous organic redox flow batteries (AORFBs) are a promising electrochemical technology for large-scale energy storage. We report a biomimetic, ultra-stable AORFB utilizing an amino acid functionalized phenazine (AFP). A series of AFPs with various commercial amino acids at different substituted positions were synthesized and studied. 1,6-AFPs display much higher stability during cycling when compared to 2,7- and 1,8-AFPs. Mechanism investigations reveal that the reduced 2,7- and 1,8-AFPs tend to tautomerize and lose their reversible redox activities, while 1,6-AFPs possess ultra-high stability both in their oxidized and reduced states. By pairing 3,3'-(phenazine-1,6-diylbis(azanediyl))dipropionic acid (1,6-DPAP) with ferrocyanide at pH 8 with 1.0 M electron concentration, this flow battery exhibits an OCV of 1.15 V and an extremely low capacity fade rate of 0.5 % per year. These results show the importance of molecular engineering of redox-active organics for robust redox-flow batteries.

Biomimetic Amino Acid Functionalized Phenazine Flow Batteries with Long Lifetime at Near‐Neutral pH

AbstractAqueous organic redox flow batteries (AORFBs) are a promising electrochemical technology for large‐scale energy storage. We report a biomimetic, ultra‐stable AORFB utilizing an amino acid functionalized phenazine (AFP). A series of AFPs with various commercial amino acids at different substituted positions were synthesized and studied. 1,6‐AFPs display much higher stability during cycling when compared to 2,7‐ and 1,8‐AFPs. Mechanism investigations reveal that the reduced 2,7‐ and 1,8‐AFPs tend to tautomerize and lose their reversible redox activities, while 1,6‐AFPs possess ultra‐high stability both in their oxidized and reduced states. By pairing 3,3′‐(phenazine‐1,6‐diylbis(azanediyl))dipropionic acid (1,6‐DPAP) with ferrocyanide at pH 8 with 1.0 M electron concentration, this flow battery exhibits an OCV of 1.15 V and an extremely low capacity fade rate of 0.5 % per year. These results show the importance of molecular engineering of redox‐active organics for robust redox‐flow batteries.

The 1H and 13C chemical shifts of 5–5 lignin model dimers: An evaluation of DFT functionals

The calculations of 1H and 13C NMR chemical shifts were performed on three 5–5 lignin dimers, prominent substructures in softwood lignins, to compare with experimental data. Initially, 10 DFT functionals (B3LYP, B3PW91, BPV86, CAM-B3LYP, HCTH, HSEH1PBE, mPW1PW91, PBEPBE, TPSSTPSS, and ωB97XD) combined with the gage-including atomic orbital (GIAO) method and basic set 6–31G(d,p) were tested on 3,3′-(6,6′-dihydroxy-5,5′-dimethoxy-[1,1′-biphenyl]-3,3′-diyl)dipropionic acid (1), efficiently synthesized from ferulic acid. HSEH1PBE, mPW1PW91, and ωB97XD were found to be the three best performing functionals with strong correlations (r2 ≥ 0.9988) and low errors (CMAEs ≤ 0.0611 ppm for 1H and CMAEs ≤ 1.19 ppm for 13C). These functionals were also well-performed for the 1H and 13C shift calculations of dimers 3,3′-dimethoxy-5,5′-dimethyl-[1,1′-biphenyl]-2,2′-diol (2) and 5,5′-diallyl-3,3′-dimethoxy-[1,1′-biphenyl]-2,2′-diol (3). Overall, the ωB97XD functional consistently provided the calculated 1H and 13C chemical shifts with a high level of accuracy.

Biobased Pyrazine-Containing Polyesters

A set of 12 first-in-class, biobased pyrazine-containing polyesters was synthesized based on dimethylpyrazine dipropionic acid. These new diacid monomers were obtained from underutilized nitrogen-r...

Exploiting a new europium(III) coordination polymer based on a zwitterionic ligand as a fluorescent probe for uranyl cations

Two new isostructural lanthanide(III) coordination polymers based on an unreported zwitterionic ligand, namely, [Ln(ox)(L)]n (ox = oxalate, HL = N,N'-dipropionic acid imidazolium, Ln = Eu or La), are synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. The fluorescence properties of the europium coordination polymer are investigated. In addition, the europium-based coordination polymer is utilized for specific sensing of UO22+ ions, showing high selectivity, a fast response time (8 min) and high sensitivity with noticeable quenching ( Ksv = 6.19 × 104 M−1) and limit of detection of 1.95 µM.

New 2D Lanthanide MOFs Constructed from Bis(imide) Pyromellitic Alanine Ligands with Enhanced Fluorescence toward Activation and Modulation of Microstructure

Five isostructural 2D lanthanide (Ln) MOFs were synthesized using 2,2′-(1,3,5,7-tetraoxo-5,7-dihydropyrrolo[3,4-f]isoindole-2,6(1H,3H)-diyl)dipropionic acid (PBIA ligand) semiflexible ligand and Pr/Eu/Tb/Er/Tm hydrated nitrates in DMF leading to PBIA–Pr/PBIA–Eu/PBIA–Tb/PBIA–Er/PBIA–Tm materials. New MOFs were characterized employing Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), single crystal and powder X-ray diffractions (SCXRD/PXRD), photoluminescence, and scanning electron microscopy (SEM). MOFs crystallized in P1̅ triclinic space group, developing 2D structures through different ligand coordination-conformation schemes toward dinuclear Ln–metal clusters (SBU). Materials were thermally stable ca. 400 °C, being activated partially removing DMF → Ln molecules giving PBIA–PrACT/PBIA–EuACT/PBIA–TbACT/PBIA–ErACT/PBIA–TmACT phases reorganizing the PBIA ligand toward isobidentate mode, releasing ca. two of six-coordinated DMF per SBU. Just Eu/Tb materials could be studied in the 200–800 nm range showing characteristic emission bands, and the PBIA ligand was not sensitization-suitable for other Ln emissions. Band shape modification and emission intensity enhancement of 6.7(Eu) and 30.6(Tb) resulted in Eu/Tb-activated compounds. Excitation of PBIA–Eu/PBIA–EuACT directly in Eu3+ resulted efficient, but not via the PBIA ligand. In PBIA–Tb/PBIA–TbACT compounds, PBIA ligand excitation is more efficient and PBIA–TbACT could be directly excited in Tb3+. Hence nonradiative processes are playing decisive roles in luminescent properties. Isostructural materials resulted, but different Ln-metals provided different morphologies/sizes, modulating microstructures, and luminescence properties. These materials would be candidates for molecular/ionic sensing, through emission modulation, mainly when Eu and Tb are employed as Ln.

Quantum molecular design and experimental testing of a high-performance zwitterionic corrosion inhibitor for oxidized iron surfaces

A zwitterionic-based chemical, the 3,3’-(octadecylamino)dipropionic acid, was quantum-theoretically designed to be applied as a corrosion inhibitor for protecting oxidized iron surfaces against the attack of very corrosive gasolines. Its performance, as well as those of worldwide-employed nitrogen-free carboxylic-diacid-based corrosion inhibitors, were experimentally evaluated and compared. Through Density-Functional-Theory calculations of the molecular interactions of the corrosion inhibitors with an iron-oxide cluster model, along with the experimental corrosion-inhibiting evaluations, it is revealed that the zwitterionic-based chemical substantially overcomes the performance of nitrogen-free chemicals. It is shown by the theoretical results that the two carboxylic heads of either, the zwitterionic-based or the nitrogen-free corrosion inhibitors, reinforce the octahedral coordination around the exposed Fe3+ atom of the iron oxide. Furthermore, when the zwitterionic-based chemical is bonded to the Fe3+ atom, a two-rings chelate is formed, in contrast to the one-ring chelate formed by the nitrogen-free corrosion inhibitors. Finally, it is theoretically predicted that oleic solvents improve the performance of the zwitterionic-based corrosion inhibitor because preclude the steric hindrance of nitrogen.

Two new secondary metabolites from a mangrove-derived fungus Cladosporium sp. JS1-2

One new pentenoic acid derivative, named 1,1'-dioxine-2,2'-dipropionic acid (1) and a new natural product, named 2-methylacetate-3,5,6-trimethylpyrazine (2), along with six known compounds (3-8), were obtained from the Cladosporium sp. JS1-2, an endophytic fungus isolated from the mangrove Ceriops tagal collected in South China Sea. Their structures were elucidated by detailed analysis of comprehensive spectroscopic data, and the structure of 1 was further determined by X-ray diffraction analyses. 13C NMR chemical shifts of structure 2 was further determined by GIAO based 13C NMR chemical shifts calculations. Compounds 1-4 and 6 showed growth inhibition activities against newly hatched larvae of Helicoverpa armigera Hubner with the IC50 values ranging from 100 to 150 μg ml-1. Compounds 1, 2, 4, 6 and 7 showed moderate antibacterial activities against Staphylococcus aureus with the MIC values of 25.0, 12.5, 6.25, 1.25, and 6.25 μg ml-1, respectively.

Co-hydrogelation of Dendritic Surfactant and Amino Acids in Their Common Naturally-occurring Forms: A Study of Morphology and Mechanisms

Sixteen different amino acids (AAs) presenting different side-chains as neutral nonpolar (Gly, Ala, Val, Leu, Ile, and Phe), neutral polar (Ser, Thr, Cys, Asn and Gln), acidic (Asp and Glu) and basic (Lys, Arg and His) could induce co-hydrogelation in 1% solutions of the dendritic surfactant, 3,3′-(octadecylazanediyl) dipropionic acid, at various concentration (1.6% ≤ Cco-hgel ≤ 20%). The amino acids Asp and Glu showed a strong favourable intercation with the surfactant, and, together with Leu and Gln, were identified as low-molecular-weight co-hydrogelators (Cco-hgel < 2%). Interpretation of XRD data indicated that all of the hydrogels exhibited lamellar structures with an occasional presence of AA crystallites. By using scanning electron microscopy, we found that the morphology of hydrogels comprises various particles (cloddy, platy, lath-/needle-like and amyloid-like fibrillar ones) and 3D structures (sheet-like and tubular ones). Furthermore, two mechanisms were identified for AA co-hydrogelation: (1) the interpenetration of AA crystallites and AA/surfactant lamellae, and (2) the formation of 3D solvent-trapping, mostly percolating structures.

A new twofold interpenetrated two-dimensional cadmium(II) coordination polymer constructed from 2,2'-(benzene-1,4-dicarboxamido)dipropionate.

In recent years, much initial interest and enthusiasm has focused on the self-assembly of coordination polymers due to the aesthetics of their crystalline architectures and their potential applications as new functional materials. As part of an exploration of chiral coordination polymers, a new twofold interpenetrated two-dimensional (2D) coordination polymer, namely, poly[[tetraaquabis[μ3-(2R,2'R)-2,2'-(benzene-1,4-dicarboxamido)dipropionato-κ5O,O':O'',O''':O'']dicadmium(II)] trihydrate], {[Cd2(C14H14N2O6)2(H2O)4]·3H2O}n, has been synthesized by the reaction of Cd(CH3COO)2·2H2O with the designed ligand (2R,2'R)-2,2'-(benzene-1,4-dicarboxamido)dipropionic acid (H2L). The compound has been structurally characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction analysis. In the crystal structure, each CdII cation binds to three carboxylate groups from two crystallographically independent L2- dianions. Four carboxylate groups link two crystallographically independent cadmium cations into a 4,4-connected secondary building unit (SBU). The resulting SBUs are extended into a two-dimensional folding sheet via the terephthalamide moiety of the ligand as a spacer, which can be simplified as a (4,4)-connected 4,4L15 net with the point symbol (3.53.62)(32.52.62). In the lattice, two independent folding sheets interpenetrate each other to yield a double-sheet layer. The resulting 2D layers pack in parallel arrays through intermolecular hydrogen bonds and interlayer π-π interactions. The thermal stability and photoluminescence properties of the title compound have been investigated and it exhibits an enhanced fluorescence emission and a longer lifetime compared with free H2L.

Synthesis, crystal structure and fluorescent properties of indolo[3,2-b]carbazole-based metal–organic coordination polymers

A new 5,11-dihydroindolo[3,2-b]carbazole-based bidentate ligand bearing two carboxylic groups, (3,3′-(indolo[3,2-b]carbazole-5,11-diyl)dipropionic acid, H2icdc), has been synthesized in two steps and then used for the construction of two metal–organic coordination polymers, namely [Zn3(dmf)2(icdc)3]·4DMF (1) and [Zn2(dabco)(icdc)2]·4NMP·4H2O (2) (dabco = 1,4-diazabicyclo[2.2.2]octane, DMF = N,N-dimethylformamide, NMP = N-methyl-2-pyrrolidone). Compound 1 has a layered structure, while compound 2 has a 3D framework structure. Both compounds display linker-based blue fluorescence.

Water-soluble complex formation of fullerene and thermo-responsive diblock copolymer

A diblock copolymer (P98N100) composed of a biocompatible water-soluble block (PMPC) and a lower critical solution temperature (LCST) type thermo-responsive block (PNIPAM) was prepared via controlled radical polymerization. To dissolve fullerene (C60) in water, the C60/P98N100 complex was prepared by mixing C60 and P98N100 powders. The maximum solubilized C60 concentration in water was 1.39 g/L, as estimated from UV–vis adsorption, when the polymer concentration was 5.0 g/L. The percent transmittance of the aqueous solution of the C60/P98N100 complex decreased above 36 °C due to inter-complex association above the LCST for the PNIPAM block. While the hydrodynamic radius of C60/P98N100 complex was 135 nm at 20 °C, it increased to 161 nm at 50 °C. Despite the observation of 1H NMR signals from PMPC and PNIPAM blocks for the C60/P98N100 complex in D2O at room temperature, the signals from PNIPAM disappeared above 35 °C due to restricted motion of PNIPAM. Generation of singlet oxygen (1O2) from the C60/P98N100 complex by photo-irradiation was confirmed using 9,10-anthracene dipropionic acid (ADPA). The absorbance of ADPA decreased with increasing irradiation time due to oxidation of ADPA by 1O2. It is expected that the C60/P98N100 complex can be applied as a thermo-responsive carrier for photodynamic therapy. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017