New Schiff base polymers poly[4,4'-methylenebis(cinnamaldehyde)ethylenediimine] (PMBCen), poly[4,4'- methylenebis(cinnamaldehyde)1,2-propylenediimine] (PMBCPn), poly[4,4'-methylenebis(cinnamaldehyde)1,3-p...New Schiff base polymers poly[4,4'-methylenebis(cinnamaldehyde)ethylenediimine] (PMBCen), poly[4,4'- methylenebis(cinnamaldehyde)1,2-propylenediimine] (PMBCPn), poly[4,4'-methylenebis(cinnamaldehyde)1,3-propylenediimine] (PMBCPR), poly[4,4'-methylenebis(cinnamaldehyde) 1,2-phenylenediimine] (PMBCPh), poly[4,4'-methylenebis(cinnamaldehyde)meso-stilbenediimine] (PMBCS), poly[4,4'-methylenebis(cinnamaldehyde)urea] (PMBCUR), poly[4,4'- methylenebis(cinnamaldehyde)semicarbazone] (PMBCSc), poly[4,4'-methylenebis(cinnamaldehyde)thiosemicarbazone] (PMBCTSc) and poly[4,4'-methylenebis(cinnamaldehyde)hydrazone] (PMBCH) were formed by polycondensation of 4,4'- methylenebis(cinnamaldehyde) with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ^1H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.展开更多
A series of new Schiff base polyamides(PAs) were synthesized by polycondensation of benzilbisthiosemicarbazone diamine(LH6) with different commercially available aliphatic and aromatic diacid chlorides. The monome...A series of new Schiff base polyamides(PAs) were synthesized by polycondensation of benzilbisthiosemicarbazone diamine(LH6) with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,^1H-NMR,and elemental analysis.The prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular weight.The PAs were completely soluble in aprotic polar solvents such as dimethylformamide(DMF),N-methylpyrolidone(NMP), tetrachloroethane(TCE),dimthylsulfoxide(DMSO) and also in H_2SO_4 and partially soluble in THF,acetone and chloroform at room temperature.Thermal analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.展开更多
Schiff base monomers [2-(4-bromobenzylideneamino)phenol and 2-(4-bromobenzylideneamino)-5-methylphenol] were synthesized by the condensation reaction of 4-bromobenzaldehyde with aromatic aminophenols. Then, the mo...Schiff base monomers [2-(4-bromobenzylideneamino)phenol and 2-(4-bromobenzylideneamino)-5-methylphenol] were synthesized by the condensation reaction of 4-bromobenzaldehyde with aromatic aminophenols. Then, the monomers were converted to their polyphenol derivatives by oxidative polycondensation reactions (OP) in an aqueous alkaline medium. The structures of the synthesized compounds were characterized by solubility tests, FT-IR, NMR, TG-DTA, DSC and SEC techniques. The HOMO-LUMO energy levels and electrochemical (E'g) and optical (Eg) band gaps were calculated from cyclic voltammetry (CV) and UV-Vis measurements, respectively. Cyclic voltammetry (CV) was used to determine the electrochemical oxidation-reduction characteristics. Optical properties were investigated by UV-Vis and fluorescence analyses. Solid state electrical conductivities were measured on polymer films by four point probe technique using a Keithley 2400 electrometer. The effects of electron-donating (--CH3) group at p-position of --NH2 group in aminophenol on electrochemical and thermal properties were also discussed. Photoluminescence (PL) properties of the synthesized materials were determined in solution forms using different solvents. Fluorescence measurements were carried out in various concentrated solutions to determine the optimum concentrations to obtain the maximal PL intensities.展开更多
A copper(Ⅱ) complex [LCu2Cl4]n was synthesized by a new bis-Schiff base ligand containing quinoline unit, 1,4-bis[2-(4-fluorophenyl)iminomethyl-8-quinolinoxy]butane(L). X-ray crystal structure shows that it is ...A copper(Ⅱ) complex [LCu2Cl4]n was synthesized by a new bis-Schiff base ligand containing quinoline unit, 1,4-bis[2-(4-fluorophenyl)iminomethyl-8-quinolinoxy]butane(L). X-ray crystal structure shows that it is a binuclear complex, and the crystal belongs to the triclinic system, space group P1, with a = 9.387(2), b = 9.968(2), c = 10.291(2) ?, α = 87.532(3), β = 63.762(2), γ = 86.628(3)o, V = 862.1(3) ?^3, Z = 1, Dc = 1.640 Mg/m^3, F(000) = 428, R = 0.0416 and wR = 0.1141. Each Cu(Ⅱ) metal ion coordinates with a quinoline N atom, an imine N atom, an ether oxygen atom and three chlorides, forming a distorted six-coordinated octahedronal structure. Each copper(Ⅱ) complexation unit links with one of the adjacent ligand copper complexation units through the chlorido bridging groups, thus generating an infinite one-dimensional chain structure. Such 1D chains further construct a 2D network structure by π-π stacking interactions.展开更多
文摘New Schiff base polymers poly[4,4'-methylenebis(cinnamaldehyde)ethylenediimine] (PMBCen), poly[4,4'- methylenebis(cinnamaldehyde)1,2-propylenediimine] (PMBCPn), poly[4,4'-methylenebis(cinnamaldehyde)1,3-propylenediimine] (PMBCPR), poly[4,4'-methylenebis(cinnamaldehyde) 1,2-phenylenediimine] (PMBCPh), poly[4,4'-methylenebis(cinnamaldehyde)meso-stilbenediimine] (PMBCS), poly[4,4'-methylenebis(cinnamaldehyde)urea] (PMBCUR), poly[4,4'- methylenebis(cinnamaldehyde)semicarbazone] (PMBCSc), poly[4,4'-methylenebis(cinnamaldehyde)thiosemicarbazone] (PMBCTSc) and poly[4,4'-methylenebis(cinnamaldehyde)hydrazone] (PMBCH) were formed by polycondensation of 4,4'- methylenebis(cinnamaldehyde) with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ^1H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.
文摘A series of new Schiff base polyamides(PAs) were synthesized by polycondensation of benzilbisthiosemicarbazone diamine(LH6) with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,^1H-NMR,and elemental analysis.The prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular weight.The PAs were completely soluble in aprotic polar solvents such as dimethylformamide(DMF),N-methylpyrolidone(NMP), tetrachloroethane(TCE),dimthylsulfoxide(DMSO) and also in H_2SO_4 and partially soluble in THF,acetone and chloroform at room temperature.Thermal analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.
文摘Schiff base monomers [2-(4-bromobenzylideneamino)phenol and 2-(4-bromobenzylideneamino)-5-methylphenol] were synthesized by the condensation reaction of 4-bromobenzaldehyde with aromatic aminophenols. Then, the monomers were converted to their polyphenol derivatives by oxidative polycondensation reactions (OP) in an aqueous alkaline medium. The structures of the synthesized compounds were characterized by solubility tests, FT-IR, NMR, TG-DTA, DSC and SEC techniques. The HOMO-LUMO energy levels and electrochemical (E'g) and optical (Eg) band gaps were calculated from cyclic voltammetry (CV) and UV-Vis measurements, respectively. Cyclic voltammetry (CV) was used to determine the electrochemical oxidation-reduction characteristics. Optical properties were investigated by UV-Vis and fluorescence analyses. Solid state electrical conductivities were measured on polymer films by four point probe technique using a Keithley 2400 electrometer. The effects of electron-donating (--CH3) group at p-position of --NH2 group in aminophenol on electrochemical and thermal properties were also discussed. Photoluminescence (PL) properties of the synthesized materials were determined in solution forms using different solvents. Fluorescence measurements were carried out in various concentrated solutions to determine the optimum concentrations to obtain the maximal PL intensities.
文摘A copper(Ⅱ) complex [LCu2Cl4]n was synthesized by a new bis-Schiff base ligand containing quinoline unit, 1,4-bis[2-(4-fluorophenyl)iminomethyl-8-quinolinoxy]butane(L). X-ray crystal structure shows that it is a binuclear complex, and the crystal belongs to the triclinic system, space group P1, with a = 9.387(2), b = 9.968(2), c = 10.291(2) ?, α = 87.532(3), β = 63.762(2), γ = 86.628(3)o, V = 862.1(3) ?^3, Z = 1, Dc = 1.640 Mg/m^3, F(000) = 428, R = 0.0416 and wR = 0.1141. Each Cu(Ⅱ) metal ion coordinates with a quinoline N atom, an imine N atom, an ether oxygen atom and three chlorides, forming a distorted six-coordinated octahedronal structure. Each copper(Ⅱ) complexation unit links with one of the adjacent ligand copper complexation units through the chlorido bridging groups, thus generating an infinite one-dimensional chain structure. Such 1D chains further construct a 2D network structure by π-π stacking interactions.