Hexa-BODIPY Linked-Triazole Based on a Cyclotriphosphazene Core as a Highly Selective and Sensitive Fluorescent Sensor for Fe<Superscript>2+</Superscript> Ions

A new type of fluorescent chemosensor based on tethered hexa-borondipyrromethene cyclotriphosphazene platform (HBTC) linked via triazole groups was designed and synthesized. Its sensing behavior toward metal ions was investigated by ultraviolet-visible and fluorescence spectroscopies. Addition of a Fe²⁺ ion to a tetrahydrofuran solution of HBTC gave a visual color change as well as a significantly quenched fluorescence emission, while other tested 19 metal ions induced no color or spectral changes. This compound was found to be highly selective and sensitive for Fe²⁺ with a low limit of detection (2.03 μM) which is, to the best of our knowledge, the superior than the previously studied chemosensors for Fe²⁺.

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Copper(II)-saccharinato complexes with piperazine and N-(2-aminoethyl)piperazine ligands

Two copper(II) complexes of the saccharinate anion (sac) with piperazine (ppz) and N-(2-aminoethyl)piperazine (aeppz), namely [Cu(sac)₂(ppz)(H₂O)]_n (1) and trans-[Cu(sac)₂(aeppz)₂] (2), have been synthesized and characterized by elemental analyses, UV–Vis, FT-IR, TGA/DTA, X-ray diffraction and magnetic measurements. The ppz ligands in 1 bridge the copper(II) centers through both nitrogen atoms to form a 1D helical chain structure and the distorted trigonal-bipyramidal coordination geometry at each copper center is completed by an aqua and a pair of N-bonded sac ligands. The helical chains are linked by Ow–H?O hydrogen bonds to build a 2-D network. In complex 2, copper(II) ions are octahedrally coordinated by two sac anions and two neutral aeppz ligands, displaying a distorted octahedral coordination. Sac is O-bonded via the carbonyl group, while ppzea acts as a N,N′-bidentate chelating ligand. The molecules are connected by N–H?N and N–H?O hydrogen bonds, forming a linear chain. In the thermal decomposition of both complexes, the removal of the aqua and ppz or aeppz ligand takes place endothermically in the first stages and the sac moiety undergoes highly exothermic decomposition at higher temperatures to give CuO.     

The syntheses of some novel (naphthalen-1-yl-selenyl)acetic acid derivatives

Some new (naphthalen-1-yl-selenyl)acetic acids derivatives 7a-d have been synthesized by two different methods, using naphthylselenols or naphthylselenocyanates. The structures of the products were investigated by spectroscopic methods.     

Synthesis and anticancer activity of some novel benzothiazole-thiazolidine derivatives

Sixteen new 2-(benzothiazol-2-ylthio)-N′-(3-substituted-4-(3,4-substitutedphenyl)thiazol-2(3H)-ylidene)acetohydrazide derivatives (4a-4p) were synthesized. The structures of the synthesized compounds were elucidated using FT-IR, ¹H-NMR, ¹³C-NMR, and HRMS spectral data. Anticancer activity of the compounds 4a-4p against C6 (rat brain glioma) and A549 (human lung adenocarcinoma) cell lines was evaluated by using MTT, inhibition of DNA synthesis, and flow cytometric analysis assays. According to MTT assay, 4a and 4d were found to be the most active compounds against C6 cell line with an IC₅₀ value of 0.03 mM. Moreover, IC₅₀ values of 4a (0.2 mM) and 4d (0.1 mM) against NIH3T3 (mouse embryo fibroblast cell line) were higher than their IC₅₀ values (0.03 mM) against C6 cell line. Accordingly, selectivity of compound 4a against C6 cell line was two-fold higher than that of compound 4d. Flow cytometry analysis showed that these compounds display anticancer activity by inducing apoptosis. As a result, compound 4a has a remarkable anticancer activity and a good selectivity towards C6 cell lines.     

Characterization and evaluation of free and nanostructured ursolic acid incorporated in cosmetic formulation using thermal analysis

The ursolic acid (UA) increases the skin’s barrier function and acts in epidermal differentiation of keratinocytes in the epidermis, promoting cell renewal. Besides the mentioned properties UA also has antioxidant, antimicrobial, and anti-irritant functions to cosmetic formulations. Thus, it is necessary formulation studies to insure the development of quality cosmetic products containing this active, increasing its antioxidant potential within nanoparticles. This study aims to characterize and evaluate the thermal behavior of UA in free and nanostructured forms, and both incorporated into a cosmetic base formulation, using thermogravimetry and differential scanning calorimetry. Through the study were observed that free UA, in the embedded nanoparticles and in base formulation exhibited different behavior in similar thermal profile and relative to the presence of UA. The UA remained stable to a temperature of 250 °C and the technique has been shown to be effective for characterizing UA, evaluate water content, and stability of the formulation base.     

Synthesis,characterization and catalytic properties of novel palladium(II) complexes containing aromatic sulfonamides: effective catalysts for the oxidation of benzyl alcohol

In this article, N‐(2‐aminophenyl)arylsulfonamides (1–5) were successfully synthesized by the reaction of o‐phenylenediamine and various benzenesulfonyl chlorides. The Schiff base derivatives (1a–f; 4e) of those compounds were obtained using different aldehydes. Then, a series of neutral‐four coordinate Pd(II) complexes (6–10) were prepared from the reaction of Pd(OAc)₂ and 1–5. On the other hand, when we tried to synthesize Pd(II) complexes containing Schiff base/sulfonamide ligands, two different situations were observed. Generally, when an electron‐donating group was attached to the imine fragment (1a–d) except for 1f, the Schiff base hydrolyzed and 6 was isolated. When an electron‐withdrawing group was attached to the imine fragment (1e, 4e), neutral four‐coordinate Pd(II) complexes (11–13) bearing Schiff base/sulfonamide ligands were isolated. The synthesized compounds were characterized by FT‐IR, elemental analysis and NMR spectroscopy. The complexes were used as a catalyst in the oxidation reaction of benzyl alcohol to benzaldehyde in the presence of H₅IO₆ in acetonitrile. All complexes showed satisfactory catalytic activity. The highest catalytic activity was obtained with 9. Copyright © 2012 John Wiley & Sons, Ltd.     

Stimuli‐responsive diblock copolymer brushes via combination of “click chemistry” and living radical polymerization

pH‐ and temperature‐responsive poly(N‐isopropylacrylamide‐block?4‐vinylbenzoic acid) (poly(NIPAAm‐b‐VBA)) diblock copolymer brushes on silicon wafers have been successfully prepared by combining click reaction, single‐electron transfer‐living radical polymerization (SET‐LRP), and reversible addition‐fragmentation chain‐transfer (RAFT) polymerization. Azide‐terminated poly(NIPAAm) brushes were obtained by SET‐LRP followed by reaction with sodium azide. A click reaction was utilized to exchange the azide end group of a poly(NIPAAm) brushes to form a surface‐immobilized macro‐RAFT agent, which was successfully chain extended via RAFT polymerization to produce poly(NIPAAm‐b‐VBA) brushes. The addition of sacrificial initiator and/or chain‐transfer agent permitted the formation of well‐defined diblock copolymer brushes and free polymer chains in solution. The free polymer chains were isolated and used to estimate the molecular weights and polydispersity index of chains attached to the surface. Ellipsometry, contact angle measurements, grazing angle‐Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy were used to characterize the immobilization of initiator on the silicon wafer, poly(NIPAAm) brush formation via SET‐LRP, click reaction, and poly(NIPAAm‐b‐VBA) brush formation via RAFT polymerization. The poly(NIPAAm‐b‐VBA) brushes demonstrate stimuli‐responsive behavior with respect to pH and temperature. The swollen brush thickness of poly(NIPAAm‐b‐VBA) brush increases with increasing pH, and decreases with increasing temperature. These results can provide guidance for the design of smart materials based on copolymer brushes. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2677–2685     

Novel K+-doped Na0.6Mn0.35Fe0.35Co0.3O2 cathode materials for sodium-ion batteries: synthesis,structures, and electrochemical properties

Journal of Solid State Electrochemistry - A series of novel KxNa0.6-xMn0.35Fe0.35Co0.3O2 (x = 0, 0.005, 0.01, 0.05, 0.1) materials were successfully synthesized by the solid-state...     

An Entry into Obtaining Pyrazole‐, Chromone‐, or Oxadiazole‐Substituted 1H‐Pyrazoles via 2,3‐Furandiones

Some new pyrazole‐, chromone‐, or oxadiazole‐substituted 1H‐pyrazoles were obtained via 2,3‐furandiones. Also, we have presented their plausible mechanisms based on rearrangement; one of these rearrangements is Baker–Venkataraman.     

Synthesis and electrochemical properties of calix[4]arene derivatives containing ferrocene units in the cone and 1,3-alternate conformation

Two novel calix[4]arene receptors containing ferrocene units in cone (L₁) and 1,3-alternate (L₂) conformations have been synthesized from 25,27-dihydroxy-26,28-bis[(3-aminopropyl)oxy]calix[4]arene 4 or 25,26,27,28-tetra[(3-aminopropyl)oxy]calix[4]arene 6 and ferrocenecarboxaldehyde via condensation, respectively. Their structures have been characterized by ¹H, ¹³C, APT, COSY NMR, FTIR, HSMR, and UV–vis spectral data. The electrochemical behavior of L₁ and L₂ has been investigated in the presence of F^?, Cl^?, Br^?, H₂PO₄^?, CH₃COO^? anions. Electrochemical studies show that these receptors electrochemically recognize CH₃COO^?, H₂PO₄^?, and Cl^?, anions. Using an UV–vis study, the selectivity to these anions in DMSO solution was confirmed.