Photo‐Induced Cross‐Linking of Divinyl Ethers by Using Diphenyliodonium Salts With Highly Nucleophilic Counter Anions in the Presence of Zinc Halides

This study describes the use of diphenyliodonium salts with highly nucleophilic counter anions to photoinitiate the cationic cross‐linking of divinyl ethers. Both direct and indirect initiating modes are used. In the direct acting system, only a diphenyliodonium salt with a highly nucleophilic counter anion and a zinc halide are employed as initiator and activator, respectively. In the indirect systems, in addition to direct system components, photosensitive additives such as anthrecene, perylene, 2,2‐dimethoxy‐2‐phenyl acetophenone, benzophenone, and thioxanthone, which absorb the energy of the incident light and activate the iodonium salt, are used to initiate polymerization. All systems employed in this study initiated quite vigorous polymerizations.

     

Anticarcinogenic and antimitotic effects of Turkish propolis and mitomycin-C on tissue cultures of bladder cancer

The in vitro anticarcinogenic and antimitotic effects of propolis and mitomycin-C (MMC) on transitional carcinoma cell cultures were investigated. Tissue samples were obtained from 22 patients with bladder carcinomas, which were exposed to propolis (0.1 mL) and MMC (1.6 microL). The mean MI rates for control, propolis and MMC were 8.327 +/- 0.624, 6.990 +/- 0.519 and 5.423 +/- 0.479, respectively. The differences between the control and exposed cells were significant (p < 0.05). We conclude that exposure to propolis can decrease cell division and it may be used as an antimitotic and anticarcinogenic agent.     

Phosphonium Salts of 1,8‐Bis(diphenylphosphino)naphthalene: Molecular Structures and NMR‐spectroscopic Studies

A representative series of diphosphine monophosphonium salts [1‐Ph₂P(C₁₀H₆)‐8‐PRPh₂]⁺X^– ( 2 b : R = H, X = CF₃SO₃; 4 : R = Me, X = CF₃SO₃; 5 : R = C₆H₅CH₂ = Bn, X = Br) has been prepared by treatment of 1,8‐bis(diphenylphosphino)naphthalene (dppn, 1 ) with stoichiometric amounts of HSO₃CF₃ or CH₃SO₃CF₃ in CH₂Cl₂ at +20 °C and with C₆H₅CH₂Br in toluene at +80 °C. Their X‐ray crystal structures show that there is no evidence for dative P → P⁺ interactions. Instead, steric repulsion deflects the substituent groups to opposite faces of the naphthalene plane [splay angles: +11.4° ( 2 b ), +13.6° ( 4 ); +16.7° ( 5 )]. In solution 2 b , 4 , and 5 were dynamic according to ³¹P, ¹³C, and ¹H NMR spectroscopy. The fluxionality of 2 b involves rapid intramolecular proton exchange between the two phosphorus atoms, which slows down at low temperature, whereas the dynamic behaviour of 4 and 5 is interpreted in terms of hindered rotation of the bulky RPh₂P⁺ groups (R = Me or Bn) about the P–C(naphthyl) bond. Treatment of 1,8‐bis(diphenylphosphoryl)naphthalene (dppnO₂, 6 ) with HSO₃CF₃ gave the protonated bis(phosphine oxide), as the triflate salt, dppnO₂H⁺ CF₃SO₃^– ( 7 ). The X‐ray structure analysis of 7 revealed a highly strained molecule (P1…P2 365.5 pm) in which the P=O bonds point to the same face of the naphthalene plane to accommodate the proton. All isolated compounds were characterised by a combination of ³¹P, ¹H, and ¹³C NMR spectroscopy, IR spectroscopy ( 7 ), mass spectrometry and elemental analysis.     

Synthesis and characterization of polypropylene-graft-poly(l-lactide) copolymers by CuAAC click chemistry

The syntheses of polypropylene-graft-poly(l -lactide) copolymers (PP-g-PLAs) via copper (I)-catalyzed azide-alkyne cycloaddition “click” reaction (CuAAC) using azide side-chain functionalized polypropylene (PP-N₃) and alkyne end-functionalized poly(l -lactide) (PLA-Alkyne) were reported. The CuAAC was then applied to azide and different feeding ratios of alkyne functional polymers to give PP-g-PLAs that were characterized by FTIR, ¹H-NMR, GPC, DSC, and WCA measurements. The CuAAC click reaction was achieved by two different feeding ratio (PP-N₃:PLA-Alkyne = 1:5 and 1:10) and thermal, biodegradable, and surface properties of obtained graft copolymers were investigated. The molar ratio of PLA were calculated as 72.7 (PP-g-PLA-1) and 78.4% (PP-g-PLA-2) by ¹H-NMR spectroscopy. The water contact angle (WCA) values of PP-g-PLA-1 (81^o ± 1.3) and PP-g-PLA-2 (75^o ± 1.6) copolymers were compared with commercial chlorinated polypropylene (PP-Cl) (90^o ± 1.0), suggesting a more hydrophilic nature of desired graft copolymers produced. Conversely, the enzymatic biodegradation studies revealed that the weight losses of graft copolymers were determined as 13.6 and 22.1%, which is about 4% for commercial PP-Cl sample. Thus, it was clear that this simple and facile method was effective in promoting biodegradation of commercial polypropylene and attractive particularly for worldwide environmental remediation goals. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2595–2601     

Synthesis,characterization, and investigations of antimicrobial activity of benzopyrans,benzofurans and spiro[4.5]decanes

In this study, the radical cyclization reactions of cyclic 1,3-dicarbonyl compounds (1a–c) and α,β-unsaturated alcohols (2a–d) through Mn(OAc)₃ were performed. A series of biologically interesting dihydropyrans (3–5) and dihydrofurans (6–18) were synthesized as a result of these reactions. Spiro compounds (19–20) were obtained from the reactions of 1,3-dicarbonyl compounds and (E)-2,4-diphenyl-but-3-en-2-ol (2e). The unique structure of compound 19 was also confirmed by X-ray crystallography. In addition, the antibacterial activities of synthesized compounds were screened against some bacteria. Their zone diameters showed better results than some known antibiotics.     

Star polymers by photoinduced copper‐catalyzed azide–alkyne cycloaddition click chemistry

Well‐defined star polymers consisting of tri‐, tetra‐, or octa‐arms have been prepared via coupling‐onto strategy using photoinduced copper(I)‐catalyzed 1,3‐dipolar cycloaddition click reaction. An azide end‐functionalized polystyrene and poly(methyl methacrylate), and an alkyne end‐functionalized poly(ε‐caprolactone) as the integrating arms of the star polymers are prepared by the combination of controlled polymerization and nucleophilic substitution reactions; whereas, multifunctional cores containing either azide or alkyne functionalities were synthesized in quantitatively via etherification and ring‐opening reactions. By using photoinduced copper‐catalyzed azide–alkyne cycloaddition (CuAAC) click reaction, reactive linear polymers are simply attached onto multifunctional cores to form corresponding star polymers via coupling‐onto methodology. The chromatographic, spectroscopic, and thermal analyses have clearly demonstrated that successful star formations can be obtained via photoinduced CuAAC click reaction. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1687–1695     

A Diverse‐Stimuli Responsive Chemiluminescent Probe with Luminol Scaffold and Its Electropolymerization

A diverse‐stimuli responsive chemiluminescent system, SNS‐Lum, and its electropolymerization to give PSNS‐Lum, which is the first example of conjugated polymers with pendant luminol arms inducing chemiluminescence in the presence of super oxide radical anion under neutral conditions, are highlighted.     

The Infrared and Raman Spectra of 4-Phenylpyridine and Its Hofmann Type Complexes.

Abstract

The Infrared and Raman spectra of 4-Phenylpyridine are reported for the first time in the 4000-400cm^?1 range. Vibrational assignments have been made for fundamental modes on the basis of frequency shifts of coordinated legend, infrared and Raman band contours and comparisons with the assignments for related molecules. The infrared spectra of M (4-Phenylpyridine) Ni(CN)₄ complexes (M=Mn, Ni or Cd) are reported. Their structure consists of polymeric layers of [M-Ni(CN)₄]_∞ with the 4-phenylpyridine molecules bound to metal (M), similar to the structure found in Hoffmann type host complexes.     

Differing Averaged and Quenched Large Deviations for Random Walks in Random Environments in Dimensions Two and Three

We consider the quenched and the averaged (or annealed) large deviation rate functions I _q and I _a for space-time and (the usual) space-only RWRE on \mathbbZ^d{\mathbb{Z}^d} . By Jensen’s inequality, I _a  ≤ I _q . In the space-time case, when d ≥ 3 + 1, I _q and I _a are known to be equal on an open set containing the typical velocity ξ _o . When d = 1 + 1, we prove that I _q and I _a are equal only at ξ _o . Similarly, when d = 2 + 1, we show that I _a  < I _q on a punctured neighborhood of ξ _o . In the space-only case, we provide a class of non-nestling walks on \mathbbZ^d{\mathbb{Z}^d} with d = 2 or 3, and prove that I _q and I _a are not identically equal on any open set containing ξ _o whenever the walk is in that class. This is very different from the known results for non-nestling walks on \mathbbZ^d{\mathbb{Z}^d} with d ≥ 4.