Air O2 Oxidant Research Articles

Synthesis, characterization of poly(E)-3-amino-4-((3-bromophenyl)diazenyl)-1H-pyrazol-5-ol: Investigation of antibacterial activity, fluorescence, and optical properties

The oxidative polycondensation reaction conditions of (E)-3-amino-4-((3-bromophenyl)diazenyl)-1H-pyrazol-5-ol (Schiff base monomer) has been accomplished using NaOCl, and air O2 oxidants in an aqueous alkaline medium. The optical conductivity, dielectric and optical properties of synthesized poly(Schiff base) were examined. The magnitude of the refractive index decreases with increasing of photon energy up to about 2.5 eV, then refractive index of the poly(Schiff base) increases with increasing of photon energy. The E0 and Ed values of the poly(Schiff base) were found to be 5.34 and 9.22 eV, respectively. An indirect energy-gap value of the poly(Schiff base) was found to be 0.94±0.009 eV. A direct energy-gap value of the poly(Schiff base) was found to be 1.38±0.01 eV and 1.96±0.009 eV at first region and second region, respectively. Absorption coefficient K changes from 11.87 to 18.25 cm−1. In addition to fluorescence property of poly(Schiff base) was investigated. Finally, poly(Schiff base) and Schiff base monomer were tested for antibacterial activities against some bacteria.

SYNTHESIS, CHARACTERIZATION, THERMAL ANALYSIS, CONDUCTIVITY AND BAND GAPS OF OLIGO {4-[(2-HYDROXYL-1-NAPHTHYL)METHYLENE]-AMINOBENZOIC ACID}

The oxidative polycondensation reaction conditions of 4-((2-hydroxyl-1-naphthyl)methylene)aminobenzoic acid (4-HNMABA) with H2O2, air O2 and NaOCl were studied in an aqueous alkaline medium between 40°C and 90°C. The structure of oligo {4-((2-hydroxyl-1-naphthyl)methylene)aminobenzoic acid} (O-4-HNMABA) was characterized by using 1 H-NMR, 13 C-NMR, FT-IR, UV-Vis, size exclusion chromatography (SEC) and elemental analysis techniques. At the optimum reaction conditions, the yield of O-4-HNMABA was found to be 70% for H2O2 oxidant, 94% for air O2 oxidant and 87% for NaOCl oxidant. According to the SEC analysis, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of O-4-HNMABA were found to be 850, 1350 and 1.59, using H2O2, 1800, 2200 and 1.22, using air O2 and 2200, 3000 and 1.36, using NaOCl, respectively. TGA-DTA analyses showed that O-4-HNMABA was more stable than 4-HNMABA. The highest occupied molecular orbital, the lowest unoccupied molecular orbital and electrochemical energy gaps ( ' Eg ) of 4-HNMABA and O-4-HNMABA were found to be −6.34, −6.56; −2.67, −3.04; 3.67 and 3.52 eV, respectively, by cyclic voltammetry (CV). According to UV-Vis measurements, optical band gaps (Eg) of 4-HNMABA and O-4-HNMABA were found to be 3.12 and 3.03 eV, respectively.

Synthesis, characterization, thermal stability, conductivity and band gaps of monomer and oligo-4-[(thien-2-ylmethylene) amino] phenol

AbstractIn this study, the oxidative polycondensation reaction conditions of 4- [(thien-2-yl-methylene) amino] phenol (4-TMAP) by using oxidants such as air O2, H2O2 and NaOCl were studied in an aqueous alkaline medium between 313 and 363 °K. The structures of the synthesized monomer and oligomer were confirmed by FT-IR, UV-vis, NMR and elemental analysis. The characterization was made by TG-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of oligo-4-[(thien-2-yl-methylene) amino] phenol (O-4- TMAP) was found to be 36% for air O2 oxidant, 40% for H2O2 oxidant and 47% for NaOCl oxidant. According to TG analysis, the weight losses of 4-TMAP and O-4- TMAP were found to be 58.11% and 51.38% at 1273°K, respectively. O-4-TMAP was shown higher stability against thermal decomposition. Also, electrical conductivity of the O-4-TMAP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and electrochemical energy gaps ( ' gE ) of 4- TMAP and O-4-TMAP were found to be -6.13, -6.02; -2.72, -2.69; 3.41 and 3.33 eV, respectively.

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

AbstractIn 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 (Mn), weight–average molecular weight (Mw), 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 (Eg) 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, characterization, and thermal stability of azomethine oligomer and its metal complexes

AbstractThe oxidative polycondensation reaction conditions of N,N′‐bis[(2‐hydroxy‐1‐naphthyl)methylene]urea (2‐HNMU) has been accomplished using NaOCl, H2O2, and air O2 oxidants in an aqueous alkaline medium. The structures of the obtained monomer and oligomer were confirmed by FTIR, UV–vis, 1H NMR, 13C NMR, and elemental analysis. The characterization was made by TG‐DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yield of oligo‐N,N′‐bis[(2‐hydroxy‐1‐naphthyl)methylene]urea (O‐2‐HNMU) was found to be 95% (for air O2 oxidant), 51% (for H2O2 oxidant), 96% (for NaOCl oxidant). According to the SEC analysis, the number‐average molecular weight (Mn), weight‐average molecular weight (Mw), and polydispersity index values of O‐2‐HNMU was found to be 1036, 1225 g/mol, and 1.182, respectively, using H2O2, and 765, 1080 g/mol, and 1.412, respectively, using air O2, and 857, 1105 g/mol, and 1.289, respectively, using NaOCl. TG‐DTA analyses showed that O‐2‐HNMU was more stable than 2‐HNMU. According to TG analyses, the carbonaceous residue of 2‐HNMU and O‐2‐HNMU was found to be 0.49% and 2.11% at 1000°C, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Synthesis, characterization, thermal analysis, and band gap of oligo‐2‐methoxy‐6‐[(4‐methylphenyl)imino]methylphenol

AbstractThe oxidative polycondensation reaction conditions of 2‐methoxy‐6‐[(4‐methylphenyl)imino]methylphenol (2M‐4‐MPIMP) by using oxidants such as air O2, H2O2 and NaOCl were studied in an aqueous alkaline medium between 30 and 90°C. The structures of synthesized monomer and oligomer were confirmed by FTIR, UV–vis, 1H NMR, 13CNMR, and elemental analysis. The characterization was made by TG–DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yield of oligo (O)‐2M‐4‐MPIMP was 68% for air O2 oxidant, 68% for H2O2 oxidant, and 82% for NaOCl oxidant. According to the SEC analysis, the number– average molecular weight (Mn), weight–average molecular weight (Mw), and polydispersity index (PDI) values of O‐2M‐4‐MPIMP were found to be 695, 1000 g mol−1 and 1.439, using air O2, and 670, 795 g mol−1 and 1.187, using NaOCl, and 645, 790 g mol−1 and 1.225, using H2O2, respectively. TG–DTA analyses were shown to be stable of O‐2M‐4‐MPIMP against thermal decomposition. The weight losses of 2M‐4‐MPIMP and O‐2M‐4‐MPIMP were found to be 98.46% and 89.54% at 1000°C, respectively. Also, electrical conductivity of the O‐2M‐4‐MPIMP was measured, showing that the polymer is typical semiconductor. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of monomer and oligomer were determined from the onset potentials for n‐doping and p‐doping, respectively. Optical energy gaps (Eg) of 2M‐4‐MPIMP and O‐2M‐4‐MPIMP were calculated from UV–vis measurements. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL PROPERTIES OF 4-[(4-HYDROXYBENZYLIDENE) AMINO] PHENOL AND ITS POLYMER

The oxidative polycondensation reaction conditions of 4-[(4-hydroxybenzylidene) amino] phenol (4-HBAP) were studied with H2O2, air oxygen and NaOCl in an aqueous alkaline medium between 50 and 90°C. The structures of the obtained monomer and polymer were confirmed by FT-IR, UV-Vis, 1H- and 13C-NMR and elemental analysis. The characterization was made by TG-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of poly[4-(4-hydroxybenzylidene amino) phenol] (P-4-HBAP) was found to be 48.3% (for H2O2 oxidant), 80.5% (for air O2 oxidant) and 86.4% (for NaOCl oxidant). According to the SEC analysis, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of P-4-HBAP was found to be 8950, 10970 g mol-1 and 1.225, respectively, using H2O2; and 11610, 15190 g mol-1 and 1.308 respectively, using air O2 and 7900, 9610 g mol-1 and 1.216, respectively, using NaOCl. According to TG-DTA analyses, P-4-HBAP was more stable than 4-HBAP against thermal decomposition. The weight loss of P-4-HBAP was found to be 49.27% at 1000°C. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) values calculated from electrochemical measurement. Electrochemical energy gaps (Eg′) of 4-HBAP and P-4-HBAP were found to be -5.46, -5.28; -2.26, -2.67; 3.20 and 2.61 eV, respectively. According to UV-Vis measurements, optical band gap (Eg) of 4-HBAP and P-4-HBAP were found to be 3.34 and 3.01 eV, respectively. Also, antimicrobial activities of 4-HBAP and P-4-HBAP were examined against selected some bacteria. The electrical conductivity of the polymer was measured after doping with iodine.

Synthesis, characterization, and thermal degradation of oligo‐2‐(morpholinoiminomethyl)phenol and its Pb(II) complex compound

AbstractThe oxidative polycondensation reaction conditions of 2‐(morpholinoiminomethyl)phenol were studied with H2O2, air O2, and sodium hypochloride (NaOCl) oxidants in an aqueous alkaline medium between 40 and 90°C. The structure of oligo‐2‐(morpholinoiminomethyl)phenol was characterized with 1H‐ and 13C‐NMR, Fourier transform infrared, ultraviolet–visible, size exclusion chromatography, and elemental analysis techniques. Under the optimum reaction conditions, the yield of oligo‐2‐(morpholinoiminomethyl)phenol was 28% for the H2O2 oxidant, 12% for the air O2 oxidant, and 58% for the NaOCl oxidant. According to the size exclusion chromatography analysis, the number‐average molecular weight, weight‐average molecular weight, and polydispersity index of oligo‐2‐(morpholinoiminomethyl)phenol were 2420 g/mol, 2740 g/mol, and 1.187 with H2O2, 1425 g/mol, 2060 g/mol, and 1.446 with air O2, and 1309 g/mol, 1401 g/mol, and 1.070 with NaOCl, respectively. Thermogravimetry/dynamic thermal analysis showed that the oligo‐2‐(morpholinoiminomethyl)phenol–lead complex compound was more stable than 2‐(morpholinoiminomethyl)phenol and oligo‐2‐(morpholinoiminomethyl)phenol against thermal degradation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3795–3804, 2006

Synthesis, Characterization and Thermal Degradation of Oligo‐2‐[(4‐hydroxyphenyl) Imino Methyl]‐1‐naphtol and Oligomer‐Metal Complexes

The oxidative polycondensation of 2‐[(4‐hydroxyphenyl) imino methyl]‐1‐naphtol (4‐HPIMN) has been accomplished by using NaOCl, H2O2 and air O2 oxidants in aqueous alkaline medium. Optimum reaction conditions of the oxidative polycondensation and the main parameters of the process were established. At optimum reaction conditions, yield of the products were found to be 77.0%, 91.6% and 99.0% for H2O2, air O2 and NaOCl oxidants, respectively. The structures of the obtained monomer and oligomer were confirmed by FT‐IR, UV‐Vis, 1H‐ and 13C‐NMR and elemental analysis. The characterization was made by TG‐DTA, SEC and solubility tests. The 1H‐ and 13C‐NMR data shows that the polymerization proceeded by the C–C coupling of ortho positions according to –OH group of 4‐HPIMN. The molecular weight distribution values of the product were determined by using size exclusion chromatography (SEC). The number‐average molecular weight (Mn), weight‐average molecular weight (Mw) and polydispersity index (PDI) values of O‐4‐HPIMN were found to be 1777, 2225 and 1.252; 1790, 2250 and 1.257; 4540, 5139 g mol−1, and 1.132 for NaOCl, H2O2 and air O2 oxidants, respectively. According to TG analyses, the carbonaceous residue of 4‐HPIMN and O‐4‐HPIMN was found to be 28.02% and 44.22% at 1000°C, respectively. Thermal analyses of O‐4‐HPIMN‐Cd, O‐4‐HPIMN‐Co, O‐4‐HPIMN‐Cu, O‐4‐HPIMN‐Fe, O‐4‐HPIMN‐Mg, O‐4‐HPIMN‐Mn, O‐4‐HPIMN‐Ni, O‐4‐HPIMN‐Pb and O‐4‐HPIMN‐Zn oligomer‐metal complex compounds were investigated in N2 atmosphere between 15–1000°C.

Synthesis, Characterization, and Thermal Degradation of Oligo-2-[(4-Chlorophenyl) Imino Methylene] Phenol and Its Oligomer-Metal Complexes

The oxidative polycondensation reaction conditions of 2-[(4-chlorophenyl) imino methylene] phenol (CPIMP) were studied by air O2 and NaOCl oxidants at various temperatures and times. Optimum reaction conditions of air O2 and NaOCl were determined for CPIMP. Oligo-2-[(4-chlorophenyl) imino methylene] phenol (OCPIMP) was synthesized from the oxidative polycondensation of CPIMP with air O2 and NaOCl in alkaline medium between 50 and 90°C. The number-average molecular weight (Mn) weight-average molecular weight (Mw) and polydispersity index (PDI) values of OCPIMP were found to be 470 g mol−1, 895 g mol−1, and 1.90, using NaOCl, and 455 g mol−1, 765 g mol−1, and 1.68, using air O2, respectively. At the optimum reaction conditions, the yield of OCPIMP was found to be 62.80% (for air O2 oxidant) and 87.50% (for NaOCl oxidant). The OCPIMP was characterized by 1H-NMR, FT-IR, UV-Vis and elemental analysis. The thermogravimetric (TGA)-DTA analyses were shown to be stable of OCPIMP and its oligomer metal complexes (such as Co+2, Ni+2, and Cu+2) against thermo-oxidative decomposition. The weight loss of OCPIMP and its oligomer metal complexes (such as Co+2, Ni+2, and Cu+2) were found to be 98%, 85%, 80%, and 82%, respectively, at 1000°C.

The Oxidative Polycondensation of Benzylidene-4′-hydroxyanilene using Air O2, NaOCl and H2O2: Synthesis and Characterization

In this work, the oxidative polycondensation reaction conditions of benzylidene-4′-hydroxyanilene (B-4′-HA) were studied using oxidants such as air O2, H2O2 and NaOCl in an aqueous alkaline medium between 40 and 95 ○C. Oligo-benzylidene-4′-hydroxyanilene was characterized by 1H-NMR, FT-IR, UV-Vis, size exclusion chromatography (SEC) and elemental analysis techniques. The solubility of oligomer using organic solvents such as DMF, THF, DMSO, methanol, ethanol, CHCl3, CCl4, toluene, acetonitrile, ethyl acetate was investigated. According to air O2 oxidant (flow rate 8.5 L/h), the conversion of B-4′-HA was 82.0% in optimum conditions such as [B-4′-HA]0=[KOH]0=0.1015 mol/L at 50 ○C for 25 h. According to the SEC analysis, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of O-B-4′-HA were found to be 1852 g mol−1, 3101 g mol−1 and 1.675; 2123 g mol−1, 4073 g mol−1 and 1.919; 2155 g mol−1, 4164 g mol−1 and 1.932, using air oxygen, NaOCl and H2O2 oxidants, respectively. Also, Thermo gravimetric analysis (TGA) showed oligo-benzylidene-4′-hydroxyanilene to be unstable against thermo-oxidative decomposition. The weight loss of O-B-4′-HA was found to be 95.87% at 1000 ○C.

Synthesis, Characterization and Optimum Reaction Conditions of Oligo-N, N -bis (2-hydroxy-1-naphthalidene) Thiosemicarbazone

The oxidative polycondenzation reaction conditions of N, N′-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone (HNTSC) using air oxygen, H2O2 and NaOCl were studied in an aqueous alkaline medium between 50–90 °C. Oligo-N, N′-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone was characterized by 1H-NMR, FT-IR, UV-Vis, size exclusion chromatography (SEC) and elemental analysis techniques. Solubility testing of oligomer was investigated using organic solvents such as DMF, THF, DMSO, methanol, ethanol, CHCl3, CCl4, toluene acetonitrile, ethyl acetate, concentrated H2SO4 and an aqueous alkaline solution. Using NaOCl, H2O2 and air O2 oxidants, conversion to oligo-N, N′-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone (OHNTSC) of N, N′-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone was found to be 85, 80 and 76%, respectively, in an aqueous alkaline medium. According to the SEC analyses, the number-average molecular weight, weight-average molecular weight and polydispersity index values of OHNTSC synthesized were found to be 1050 g mol−1 1715 g mol−1 and 1.63, using NaOCl, and 2137, 2957 g mol−1 and 1.38, using air O2 and 2155 g mol−1 4164 g mol−1 and 1.93, using air H2O2, respectively. Also, TG analysis was shown to be unstable of oligo-N, N′-bis (2-hydroxy-1-naphthalidene) thiosemicarbazone against thermo-oxidative decomposition. The weight loss of OHNTSC was found to be 97.29% at 900 °C.

Synthesis, characterization, and optimum reaction conditions of oligo‐2‐[(pyridine‐2‐yl‐methylene) amino] phenol

AbstractThe reaction conditions of the oxidative polycondensation of 2‐[(pyridine‐2‐yl‐methylene) amino] phenol (2‐PMAP) with air O2, H2O2, and NaOCl were studied in an aqueous alkaline medium between 60 and 90 °C. Oligo‐2‐[(pyridine‐2‐yl‐methylene) amino] phenol (O‐2‐PMAP) was characterized with 1H NMR, Fourier transform infrared, ultraviolet–visible, size exclusion chromatography (SEC), and elemental analysis techniques. Moreover, solubility testing of the oligomer was performed in polar and nonpolar organic solvents. With the NaOCl, H2O2, and air O2 oxidants, the conversions of 2‐PMAP into O‐2‐PMAP were 98, 87, and 62%, respectively, in an aqueous alkaline medium. According to SEC, the number‐average molecular weight, weight‐average molecular weight, and polydispersity index of O‐2‐PMAP were 2262 g mol−1, 2809 g mol−1, and 1.24 with NaOCl, 3045 g mol−1, 3861 g mol−1, and 1.27 with air O2, and 1427 g mol−1, 1648 g mol−1, and 1.16 with air H2O2, respectively. Also, thermogravimetric analysis showed that O‐2‐PMAP was stable against thermooxidative decomposition. The weight loss of O‐2‐PMAP was 96.68% at 900 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2717–2724, 2004