The preparation,characterization, and cure reactions of new bisbenzocyclobutene‐terminated aromatic imides

Several new bisbenzocyclobutene‐terminated aromatic imides, 2,2′‐bis(N‐4‐benzocyclobutenyl) phthalimide, 2,2′‐bis[4‐(N‐4‐benzocyclobutenylphthalimide)]‐ether, 2,2′‐bis[4‐(N‐4‐benzocyclobutenylphthalimide)]‐ketone, and 2,2′‐bis[4‐(N‐4‐benzo cyclobutenylphthalimid‐4‐oxy) phenyl]‐propane, have been synthesized in high yields and characterized by FTIR, MS, EA, and ¹H NMR spectroscopy. The polymers cured from benzocyclobutene‐terminated imides have high glass transition temperature and good thermal stabilities. The cure reaction of an imide was studied by FTIR‐ATR (attenuated total reflection) and DSC techniques. Apparent kinetic parameters of the cure reaction are obtained. The apparent cure reaction order, activation energy, and pre‐exponential factor determined by isothermal DSC method are 1, 143.4 kJ/mol, and 3.88× 10¹³ min^?1, and by nonisothermal DSC methods 1, 139.4 kJ/mol, and 2.27× 10¹³ min^?1, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1705–1719, 2006     

Kinetics,degradation pathway and reaction mechanism of advanced oxidation of 4‐nitrophenol in water by a UV/H2O2 process

Photooxidation of 4‐nitrophenol (4‐NP) in water by the UV/H₂O₂ advanced oxidation process was carried out in order to investigate the kinetics and pathway of 4‐NP degradation. The experimental results showed that the photodegradation of 4‐NP accorded well with pseudo‐first order kinetics. The effects of different parameters, such as H₂O₂ dosage, pH value and various anion scavengers on the degradation of 4‐NP have been investigated in detail. It was found that acidic conditions are more favorable to the degradation of 4‐NP but many anions, such as HCO₃^?, NO₃^? and Cl^?, slow down the photooxidation rate of 4‐NP. Hydroquinone, 1,2,4‐trihdroxybenzene, 4‐nitropyrogallol, and 4‐nitrocatechol were tentatively identified as the intermediates of 4‐NP degradation by GC/MS after samples were derivatized by N,O‐bis(trimethylsilyl)‐trifluoroacetamide (BSTFA). A degradation pathway was proposed to account for the observed intermediates produced during 4‐NP degradation by the UV/H₂O₂ process. Copyright © 2003 Society of Chemical Industry     

Synthesis and proton conductivity studies of methacrylate/methacrylamide‐based azole functional novel polymer electrolytes

Anhydrous polymer electrolytes based on azole functional methacrylates and methacrylamides have been produced for use in proton exchange membrane fuel cells (PEMFCs). Poly(methacryloyl chloride) (PMAC) was prepared first by free‐radical polymerization of methacryloyl chloride, followed by side chain functionalization with 5‐aminotetrazole (ATet), 3‐amino‐1,2,4‐triazole (ATri) and 1H‐1,2,4‐triazole (Tri). Finally, the obtained polymers were doped with triflic acid (TA) at stoichometric ratios of 1.0, 2.0 and 4.0 with respect to azole units, and the anhydrous polymer electrolytes were obtained. The membranes were characterized by FT‐IR, ¹³C‐NMR, and elemental analysis. Thermal behaviour of polymers was explored by TGA and DSC. The samples were thermally stable up to approximately 200 ^oC. Proton conductivity was measured by impedance spectroscopy. Trifilic acid doped poly(methacryloyl aminotetrazole) (PMAATet‐(TA)₄), poly(methacryloyl‐3‐amino‐1,2,4‐triazole) (PMA‐Tri‐(TA)₄), and poly(methacryloyl‐1,2,4‐triazole) (PMA‐ATri‐(TA)₄) showed maximum proton conductivities of 0.01 Scm^?1, 0.02 Scm^?1 and 8.7x10^?4 Scm^?1, respectively, at 150^°C and anhydrous conditions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39915.     

Formation of thermosensitive copolymer beads having phosphinic acid groups and adsorption ability for metal ions

Hydrophilic thermosensitive copolymer beads having phosphinic acid groups were prepared by suspension copolymerization of acryloyloxypropyl n‐octylphosphinic acid (APPO), N‐isopropyl acrylamide (NIPAAm), and tetraethyleneglycol dimethacrylate (4G). The thermosensitivity and the adsorption ability of the copolymer beads for metal ions beads were studied. The APPO‐NIPAAm‐4G copolymer beads were obtained in a good yield by suspension copolymerization of monomers (APPO, NIPAAm, and 4G) dissolved in chloroform, in a saturated Na₂SO₄ aqueous solution in the presence of surfactant and MgCO₃. The APPO‐NIPAAm‐4G copolymer beads had higher adsorption ability for lanthanide metal ions (Eu³⁺, Sm³⁺, Nd³⁺, or La³⁺) than for main transition metal ions (Cu²⁺, Ni²⁺, or Co²⁺). Furthermore, it was also found that the APPO‐NIPAAm‐4G copolymer beads had selective adsorption ability between lanthanide metal ions, and the order of adsorption ability for lanthanide metal ions was as follows: Eu³⁺ > Sm³⁺ > Nd³⁺ > La³⁺. The selective adsorption for these metal ions from their mixed solutions was performed by both a batch method and a column method. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 449–460, 2006     

Structural and Thermal Characterization of A Novel High Nitrogen Energetic Material: (NH4)2DNMT

1,4‐Dihydro‐5H‐(dinitromethylene)‐tetrazole ammonium salt ((NH₄)₂DNMT), a high nitrogen energetic compound, was synthesized and structurally characterized by single‐crystal X‐ray diffraction. The thermal behavior of (NH₄)₂DNMT was studied with DSC and TG‐DTG methods. The kinetic equation of the thermal decomposition reaction is: dα/dT=10^13.17/3β(1−α)⁻² exp(−1.388×10⁵/RT). The critical temperature of thermal explosion is 182.7 °C. The specific heat capacity of (NH₄)₂DNMT was determined and the molar heat capacity is 301 J mol⁻¹ K⁻¹ at 298.15 K. The adiabatic time‐to‐explosion of (NH₄)₂DNMT was calculated to be 277 s. The detonation velocity and detonation pressure were also estimated. All results showed that (NH₄)₂DNMT presents good performance.     

Synthesis,characterization, thermal stability,conductivity, and band gap of a new aromatic polyether containing an azomethine as a side

In this study, the oxidative polycondensation reaction conditions of 4‐[(4‐methylphenyl)iminomethyl]phenol (4‐MPIMP) were studied by using oxidants such as air O₂, H₂O₂, and NaOCl in an aqueous alkaline medium between 50 and 90°C. The structures of the synthesized monomer and polymer were confirmed by FTIR, UV–vis, ¹H–¹³C‐NMR, and elemental analysis. The characterization was made by TGA‐DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yield of poly‐4‐[(4‐methylphenyl)iminomethyl]phenol (P‐4‐MPIMP) was found to be 28% for air O₂ oxidant, 42% for H₂O₂ oxidant, and 62% for NaOCl oxidant. According to the SEC analysis, the number–average molecular weight (M_n), weight–average molecular weight (M_w), and polydispersity index values of P‐4‐MPIMP were found to be 4400 g mol^?1, 5100 g mol^?1, and 1.159, using H₂O₂, and 4650 g mol^?1, 5200 g mol^?1, and 1.118, using air O₂, and 5100 g mol^?1, 5900 g mol^?1, and 1.157, using NaOCl, respectively. According to TG analysis, the weight losses of 4‐MPIMP and P‐4‐MPIMP were found to be 85.37% and 72.19% at 1000°C, respectively. P‐4‐MPIMP showed higher stability against thermal decomposition. Also, electrical conductivity of the P‐4‐MPIMP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels and electrochemical energy gaps (E) of 4‐MPIMP and P‐4‐MPIMP were found to be ?5.76, ?5.19; ?3.00, ?3.24; 2.76 and 1.95 eV, respectively. According to UV–vis measurements, optical band gaps (E_g) of 4‐MPIMP and P‐4‐MPIMP were found to be 3.34 and 2.82 eV, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis of new ionic crosslinked polymer hydrogel combining polystyrene and poly(4‐vinyl pyridine) and its self‐healing through a reshuffling reaction of the trithiocarbonate moiety under irradiation of ultraviolet light

A new ionic crosslinked polymer hydrogel was achieved by the strategy of ionically crosslinking α,ω‐dibromide terminated polystyrene (Br‐PS‐Br) with poly(4‐vinyl pyridine) (P4VP) which was synthesized by reversible addition‐fragmentation chain transfer polymerization using a chain transfer agent containing a trithiocarbonate moiety. The moiety of trithiocarbonate was introduced into the crosslinked network to show the self‐healing characteristics. The chain structure and components of Br‐PS‐Br and P4VP were characterized through ¹H NMR, gel permeation chromatography, Fourier transform IR spectroscopy and elemental analysis. The P4VP (M_n = 25 300 g mol^?1) chains were crosslinked with Br‐PS‐Br (M_n = 2000 g mol^?1) through the quaternization reaction to form a polymer network which was further crosslinked in acetonitrile by irradiation of UV light to fabricate a hydrogel. Such a hydrogel of P4VP/Br‐PS‐Br cut by a razor blade can be rapidly (1 h) and repeatedly (three times) healed through a reshuffling reaction of the trithiocarbonate moiety under irradiation by UV light. © 2018 Society of Chemical Industry     

Synthesis and Characterization of New Calixarenes Containing Explosives with High Temperature Stabilities

A few of novel, thermally stable, nitro‐substituted calixanes were successfully synthesized and their spatial configurations also were confirmed. 1⁴,1⁶,3⁴,3⁶,5⁴,5⁶,7⁴,7⁶‐octanitro‐2,4,6,8‐tetraoxa‐1,3,5,7(1,3)‐tetraben‐zenacyclooctaphane ( 7 ) as heat‐resistant explosives can be prepared by means of a facile synthetic produced and shows outstanding properties (good thermal stability and high thermal decomposition temperature and energetic performances). It has also been pointed out that the production of compound 7 is very easy on a large scale. All target compounds was characterized by single‐crystal X‐ray diffraction, NMR and elemental analysis, TG and DSC. In this paper, the macrocyclic compounds are introduced into the study as heat‐resistant explosives firstly, which will change the past stagnant situation!     

Effects of molecular weight and arm number on properties of star‐shape styrene–butadiene–styrene triblock copolymer

A star‐shape styrene–butadiene–styrene triblock copolymer SBS (802) was synthesized and fractionated into four fractions coded as 802‐F1 (four arms), 802‐F2 (two arms), 802‐F3 (one arm), and 802‐F4 by repeating fractional precipitation. Their weight‐average molecular weight (M_w) was measured by size‐exclusion chromatography combined with laser light scattering to be 16.0 × 10⁴, 8.2 × 10⁴, 4.3 × 10⁴, and 1.19 × 10⁴, respectively. The samples were, respectively, compression‐molded and solution‐cast to obtain the sheets coded as 802C, 802‐F1C, 802‐F2C, and 802S, 802‐F1S, 802‐F2S. The structures and mechanical properties of the sheets were characterized by ¹H‐NMR, scanning electron microscope, wide‐angle X‐ray diffractometer, tensile testing, and dynamic mechanical thermal analysis. The results indicated that the compression‐molded 802‐F1C exhibited the higher tensile strength (σ_b, 28.4 MPa) and elongation at break (ε_b, 1610%), and its optical transmittance is much higher than those of 802C and 802‐F2C. This work revealed that the star‐shape SBS with four arms could be helpful in the enhancement of the properties as a result of good miscibility of the compression‐molded SBS sheets. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 832–840, 2005     

Preparation and characterization of novel hybrid thermoplastic poly(ether urethane)/poly(vinylidene fluoride) elastomers,and their application as solid polymer electrolytes

A comb‐like polyether, poly(3‐2‐[2‐(2‐methoxyethoxy)ethoxy]ethoxymethyl‐3′‐methyloxetane) (PMEOX), was reacted with hexamethylene diisocyanate and extended with butanediol in a one‐pot procedure to give novel thermoplastic elastomeric poly(ether urethane)s (TPEUs). The corresponding hybrid solid polymer electrolytes were fabricated through doping a mixture of TPEU and poly(vinylidene fluoride) with three kinds of lithium salts, LiClO₄, LiBF₄ and lithium trifluoromethanesulfonimide (LiTFSI), and were characterized using differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy. The ionic conductivity of the resulting polymer electrolytes was then assessed by means of AC impedance measurements, which reached 2.1 × 10^?4 S cm^?1 at 30 °C and 1.7 × 10^?3 S cm^?1 at 80 °C when LiTFSI was added at a ratio of O:Li = 20. These values can be further increased to 3.5 × 10^?4 S cm^?1 at 30 °C and 2.2 × 10^?3 S cm^?1 at 80 °C by introducing nanosized SiO₂ particles into the polymer electrolytes. Copyright © 2006 Society of Chemical Industry     

Synthesis,Crystal Structure,and Thermal Behavior of 3‐(4‐Aminofurazan‐3‐yl)‐4‐(4‐nitrofurazan‐3‐yl)furazan (ANTF)

The energetic material 3‐(4‐aminofurazan‐3‐yl)‐4‐(4‐nitrofurazan‐3‐yl)furazan (ANTF) with low melting‐point was synthesized by means of an improved oxidation reaction from 3,4‐bis(4′‐aminofurazano‐3′‐yl)furazan. The structure of ANTF was confirmed by ¹³C NMR spectroscopy, mass spectrometry, and the crystal structure was determined by X‐ray diffraction. ANTF crystallized in monoclinic system P2₁/c, with a crystal density of 1.785 g cm⁻³ and crystal parameters a=6.6226(9) Å, b=26.294(2) Å, c=6.5394(8) Å, β=119.545(17)°, V=0.9907(2) nm³, Z=4, μ=0.157 mm⁻¹, F(000)=536. The thermal stability and non‐isothermal kinetics of ANTF were studied by differential scanning calorimetry (DSC) with heating rates of 2.5, 5, 10, and 20 K min⁻¹. The apparent activation energy (E_a) of ANTF calculated by Kissinger's equation and Ozawa's equation were 115.9 kJ mol⁻¹ and 112.6 kJ mol⁻¹, respectively, with the pre‐exponential factor lnA=21.7 s⁻¹. ANTF is a potential candidate for the melt‐cast explosive with good thermal stability and detonation performance.     

Polyaniline salt containing dual dopants,pyrelenediimide tetracarboxylic acid,and sulfuric acid: Fluorescence and supercapacitor

Storage of energy is considered as the most germane technologies to address the future sustainability. In this study, aniline was chemically oxidized with a controlled concentration of pyrelenediimide tetracarboxylic acid (PDITCA) by ammonium persulfate to polyaniline salt (PANI‐H₂SO₄‐PDITCA), with nanorods morphologies, having a sensibly decent conductivity of 0.8 S cm^?1, wherein H₂SO₄ was generated from ammonium persulfate during polymerization. PANI‐H₂SO₄‐PDITCA salt showed bathochromic fluorescence shift (595 nm) compared to PDITCA (546 nm). The Brunauer–Emmett–Teller surface area of the PANI‐H₂SO₄‐PDITCA‐25 and PANI‐H₂SO₄‐PDITCA‐50 were 18.3 and 21.4 m² g^?1, respectively. Furthermore, its energy storage efficiency was evaluated by supercapacitor cell configuration. The composite PANI‐H₂SO₄‐PDITCA‐50 showed capacitance 460 F g^?1 at 0.3 A g^?1 and large cycle life 85,000 cycles with less retention of 77% to its original capacitance (200 F g^?1) even at a better discharge rate of 3.3 A g^?1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45456.     

Mono‐, Di‐ and Tetra‐Cationic Surfactants as Carbon Steel Corrosion Inhibitors

Corrosion inhibition of three new synthesized cationic surfactants, N‐(2‐(((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)amino)ethyl)‐N‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)dodecan‐1‐aminium bromide I(4N), N¹,N²‐didodecyl‐N¹‐((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)‐N²‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)ethane‐1,2‐diaminium bromide II(4N) and 1‐dodecyl‐4‐((E)‐((2‐(dodecyl(2‐(dodecyl((Z)‐4‐(1‐dodecylpyridin‐1‐ium‐4‐yl)but‐3‐en‐1‐yl)ammonio)ethyl)ammonio)ethyl)imino)methyl)pyridin‐1‐ium bromide IV(4N) on carbon steel was investigated by weight loss, electrochemical impedance spectroscopy and polarization measurements. Results show that the synthesized cationic surfactants inhibit corrosion of carbon steel in 1 M HCl. The inhibitive action occurs by virtue of adsorption on the metal surface following a Langmuir adsorption isotherm model. Polarization curves reveal that the investigated cationic surfactants can be classified as mixed inhibitor types. The variations in the corrosion inhibition efficiency between three cationic surfactants are correlated with their chemical structures, with more hydrophobic surfactants yielding higher inhibition efficiency.     

Synthesis and Photoluminescence Characteristics of YAl3(BO3)4:Tb3+ Phosphors by Combustion Process

Terbium‐activated YAl₃(BO₃)₄ (YAl₃(BO₃)₄:Tb³⁺) phosphors were synthesized by both combustion method and solid‐state reaction. It was found that the pure‐phase YAl₃(BO₃)₄ phosphors synthesized by combustion method were obtained at 1000°C, which was 200°C lower than that by solid‐state reaction. The average particle size of the combustion‐derived phosphors increased with increasing temperatures. The luminescence characteristics in ultraviolet (UV) — vacuum ultraviolet (VUV) ranges for the YAl₃(BO₃)₄:Tb³⁺ phosphors were investigated. The bands from 175 nm to 300 nm were attributed to the 4f⁸‐4f⁷5d¹ transitions of Tb³⁺. The other strong bands in the region from 125 nm to 175 nm were assigned to host absorption. The emission spectra showed the strongest emission at 542 nm corresponding to the ⁵D₄→⁷F₅ transition of Tb³⁺. Moreover, the combustion‐derived YAl₃(BO₃)₄:Tb³⁺ phosphors generated more intense luminescence than the solid‐state‐derived phosphors under UV excitation.     

Synthesis of pentavalent imidovanadium complexes and their catalyses for the polymerization of ethylene and propylene

Imidovanadium complexes with cyclopentadienyl (Cp) ligands—(Cp)V(?NC₆H₄Me‐4)Cl₂ (1), (Cp)V(?N^tBu)Cl₂ (2), and (^tBuCp)V(?N^tBu)Cl₂ (3; ^tBuCp = tert‐butylcyclopentadienyl)—were synthesized through the reaction of imidovanadium trichloride with (trimethylsilyl)cyclopentadiene derivatives. The molecular structure of 3 was determined by X‐ray crystallography. The monocyclopentadienyl complex 1 exhibited moderate activity in combination with methylaluminoxane [MAO; 10.3 kg of polyethylene (mol of V)^?1 h^?1 atm^?1], whereas similar complexes with bulky ^tBu groups, 2 and 3, were less active. (2‐Methyl‐8‐quinolinolato)imidovanadium complexes, V(?NR)(O ?N)Cl₂ (R = C₆H₃ⁱPr₂‐2,6 (4) or n‐hexyl (5), O ?N = 2‐methyl‐8‐quinolinolato), were obtained from the reaction of imidovanadium trichloride with 2‐methyl‐8‐quinolinol. Upon activation with modified MAO, complex 4 showed moderate activities for the polymerization of ethylene at room temperature. The complex 5/MAO system also exhibited moderate activity at 0°C. The polyethylenes obtained by these complexes had considerably high melting points, which indicated the formation of linear polyethylene. Moreover, the 5/dried MAO system showed propylene polymerization activities and produced polymers with considerably high molecular weights and narrow molecular weight distributions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1008–1015, 2005     

Block copolymers of acrylonitrile and poly(dimethylsiloxane)s

The chemical redox system of ceric ammonium nitrate(Ce⁴⁺) and poly(dimethylsiloxane)s (PDMS) with monohydroxy (MH), dihydroxy (DH), and diamine(DA) chain ends was used to polymerize acrylonitrile (AN) to produce monohydroxy poly(dimethylsiloxane)s‐b‐polyacrylonitrile (MH.PDMS‐b‐PAN), dihydroxy poly(dimethylsiloxane)s‐b‐polyacrylonitrile (DH.PDMS‐b‐PAN), and α, ω‐diamine poly(dimethylsiloxane)s‐b‐polyacrylonitrile (DA.PDMS‐b‐PAN) block copolymers. The concentration, reaction time, and the type of poly(dimethylsiloxane) affect the yield and the molecular weight of the copolymers. The ratio of AN/ceric salt/PDMS has remarkably affects the properties of formed copolymers. DH.PDMS‐b‐PAN copolymers were also prepared by electroinduced polymerization in the presence of catalytic amount of Ce⁴⁺ in a divided electrochemical cell where Ce³⁺ is readily oxidized into Ce⁴⁺ at the anode. The products were characterized by Fourier transform infrared spectroscopy, ¹H‐NMR spectroscopy, DSC, and their surface properties were investigated through contact‐angle measurements. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Deep‐red photoluminescence and long persistent luminescence in double perovstkite‐type La2MgGeO6:Mn4+

A novel non‐rare‐earth doped phosphor La₂MgGeO₆:Mn⁴⁺ (LMG:Mn⁴⁺) with near‐infrared (NIR) long persistent luminescence (LPL) was successfully synthesized by solid‐state reaction. The phosphors can be effectively excited using ultraviolet light, followed by a sharp deep‐red emission peaking at 708 nm, which is originated from ²E_g → ⁴A_2g transition of Mn⁴⁺ ions. The luminescent performance was analyzed by photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The crystal field parameters were calculated to describe the environment of Mn⁴⁺ in LMG host. The LPL behaviors as well as the mechanisms were systematically discussed. This study suggests that the phosphors will broaden new horizons in designing and fabricating novel NIR long phosphorescent materials.     

O4‐Alkylated‐2‐Deoxyuridine Repair by O6‐Alkylguanine DNA Alkyltransferase is Augmented by a C5‐Fluorine Modification

Oligonucleotides containing various adducts, including ethyl, benzyl, 4‐hydroxybutyl and 7‐hydroxyheptyl groups, at the O⁴ atom of 5‐fluoro‐O⁴‐alkyl‐2′‐deoxyuridine were prepared by solid‐phase synthesis. UV thermal denaturation studies demonstrated that these modifications destabilised the duplex by approximately 10 °C, relative to the control containing 5‐fluoro‐2′‐deoxyuridine. Circular dichroism spectroscopy revealed that these modified duplexes all adopted a B‐form DNA structure. O⁶‐Alkylguanine DNA alkyltransferase (AGT) from humans (hAGT) was most efficient at repair of the 5‐fluoro‐O⁴‐benzyl‐2′‐deoxyuridine adduct, whereas the thymidine analogue was refractory to repair. The Escherichia coli AGT variant (OGT) was also efficient at removing O⁴‐ethyl and benzyl adducts of 5‐fluoro‐2‐deoxyuridine. Computational assessment of N1‐methyl analogues of the O⁴‐alkylated nucleobases revealed that the C5‐fluorine modification had an influence on reducing the electron density of the O⁴?C_α bond, relative to thymine (C5‐methyl) and uracil (C5‐hydrogen). These results reveal the positive influence of the C5‐fluorine atom on the repair of larger O⁴‐alkyl adducts to expand knowledge of the range of substrates able to be repaired by AGT.     

Synthesis,Characterization, and Antimicrobial Activity of Silver(I) and Copper(II) Complexes of Phosphate Derivatives of Pyridine And Benzimidazole

Two silver(I) complexes—{[Ag(4‐pmOpe)]NO₃}_n and [Ag(2‐bimOpe)₂]NO₃—and three copper(II) complexes—[Cu₄Cl₆O(2‐bimOpe)₄], [CuCl₂(4‐pmOpe)₂], and [CuCl₂(2‐bis(pm)Ope]—were synthesized by reaction of silver(I) nitrate or copper(II) chloride with phosphate derivatives of pyridine and benzimidazole, namely diethyl (pyridin‐4‐ylmethyl)phosphate (4‐pmOpe), 1H‐benzimidazol‐2‐ylmethyl diethyl phosphate (2‐bimOpe), and ethyl bis(pyridin‐2‐ylmethyl)phosphate (2‐bis(pm)Ope). These compounds were characterized by ¹H, ¹³C, and ³¹P NMR as well as IR spectroscopy, elemental analysis, and ESIMS spectrometry. Additionally, molecular and crystal structures of {[Ag(4‐pmOpe)]NO₃}_n and [Cu₄Cl₆O(2‐bimOpe)₄] were determined by single‐crystal X‐ray diffraction analysis. The antimicrobial profiles of synthesized complexes and free ligands against test organisms from the ATCC and clinical sources were determined. Silver(I) complexes showed good antimicrobial activities against Candida albicans strains (MIC values of ～19 μM ). [Ag(2‐bimOpe)₂]NO₃ was particularly active against Pseudomonas aeruginosa and methicillin‐resistant Staphylococcus epidermidis, with MIC values of ～5 and ～10 μM , respectively. Neither copper(II) complexes nor the free ligands inhibited the growth of test organisms at concentrations below 500 μg mL^?1.     

Complexation of titanium alkoxides with pentenoic acid and allylacetoacetate and their hydrolysis and addition reactions with H‐silanes

Complexation reactions of titanium tetraethoxide [Ti(OEt)₄] and titanium tetra‐n‐butoxide [Ti(OBuⁿ)₄] with 3‐pentenoic acid (PA) and allylacetoacetate (AAA), in a 1 : 1M ratio, were studied in ethanol solution at room temperature. ¹³C‐NMR and FTIR spectra showed that all PA and AAA completely reacted with both titanium alkoxides. Hydridosilane compounds such as triethoxysilane and triethylsilane were added to titanium chelate complexes in a 1 : 1M ratio. The investigation of products by ¹³C‐ and ²⁹Si‐NMR and FTIR showed additions of ? SiH to the C?C double bond. The hydrolysis of titanium–PA and AAA complexes, by water in 1 : 4 ratios, resulted in released PA in an amount of 10% and AAA of 20%. The stability of hydrolyzed products was investigated by ¹³C‐NMR, ²⁹Si‐NMR, and FTIR. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 790–796, 2005