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1.
Two products were isolated at a result of esterification of acrylic acid with 4-[4-(n-hydroxyundecanyloxy)phenyl] benzoic acid (5) One is 4-[4-(n-acryloloxy-undecanyloxy)phenyl] benzoic acid (6), and the other is 4-{4-[n-(3-acryloloxy-propionyloxy)undecanyloxy]phenyl}benzoic acid (7) which containts two molecules of acrylic acid. Compound7 is obtained unexpectedly and still unknown in the literature. Its identification is confirmed by the isolation and characterization of the monomer9. The mesogenic monomers8 and9 which were synthesized from 4-hydroxyphenyl 2(S)-[2(S)-methylbutoxylpropionate (4) and the corresponding acrylates6 and7 exhibit the enentiotropic Sc* and SA phases. The Sc* phase temperature range is up to 31 °C. The spontaneous polarization and response time for the monomers8 and9 is 97 and 16 nC/cm2 as well as 90 and 64 µs respectively. It us the liquid crystal side chain polymer11, not10, which is switchable in the presence of an electric field. The spontaneous polarization of 36 nC/cm2 and the response time of 3.1 ms is obtain from the new polyacrylate.  相似文献   

2.
The object of this work was to prepare organic inorganic oligomers or polymers from diisocyanates and hydroxylated cyclotriphosphazenes. The reaction of a dihydroxylated cyclotriphosphazene. (3.5-dihydroxyphenoxy)(pentaphenoxy) cyclotriphosphazene.3. obtained by the reaction of (3.5-dimethoxyphenoxy) (pentaphenoxy)cyclotriphosphazene with BBr3 H2O and two diisocyanates, toluen 2.4 (TDI)- and hexamethylene 1.6 (HDI)-diisocyanates, leads to the new cyclotriphosphazene-substituted polyurethanes,4 and5. The structures of both classes of compounds were investigated by31P.13C. and1H NMR. infrared spectroscopy, mass spectrometry, and elemental analysis. The molecular weights of polymers were determined by SEC analysis. The thermal behavior of the new polyurethanes was investigated. The thermogravimetric analysis indicates that incorporation of cyclotriphosphazene moiety as a pendant group leads to increased thermal stability.  相似文献   

3.
The role of cyclophosphazenes with oxyethylene chains (N3P3(OCH2CH2)nOCH3, (n = 3, 3, n = 7.2, 4) and N4P4[OC6H4O(CH2CH2O)7.2CH3]8 (8) for the synthesis and ionic conductivity in polymethacrylate networks was studied. Reflecting the structural features of cyclophosphazenes, the 7Li NMR spectra of the mixture of 3 and LiN(SO2CF3)2 showed that more than 40% of the Li+ salt could exist as a free ion at room temperature. Similar values were obtained for 4 and 8. Cross-linked methacrylate polymers (1214, and 1618) were prepared from the reaction of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate both in the presence of these cyclophosphazenes which act as molecular imprinting molecules (method II, M-II) and without the cyclophosphazene (method I) DSC studies of the imprinted polymer, 12(20)/3/Li+ system after removal of the cyclophosphazene showed that the glass transition temperature range (ΔTg) becomes significantly narrower compared to that of the unimprinted 11(20)/3/Li+ system, where cross-linked polymer 11(20) was prepared in the absence of the cyclophosphazenes (method I, M-I). The ionic conductivity of the Li+/cross-linked polymer system was improved by the subsequent readdition of the cyclophosphazenes. The 12(20)/3/Li+ complex showed a conductivity of 1.1 × 10−3 S/cm at 90 °C, which was two times higher than that of the 11(20)/3/Li+ complex. The effectiveness of the small molecule imprinting technique for the preparation of cross-linked polyelectrolytes with high conductivity and mechanical stability is discussed. We dedicate this paper to Professor Christopher W. Allen for his creative, pioneering work in inorganic ring and inorganic-organic hybrid polymers.  相似文献   

4.
Hexakist 4-formylphenoxy cyclophosphazene (1) reacts with six equivalents of cyanomethylenetriphenylphosphorane to give hexakist 4-cinnamonitrile cyclotriphosphazene bearing 12 functional groups tsix nitriles and six olefins' able to coordinate up to 12 metals. In this way a series of polynuclear phosphazene metal derivatives (8–12) was prepared with different transition metals and in different oxidation states. Pt(0), Pt(II) and Rh(I). The analogous cinnamonitrile derivatives (3–7) were prepared and used as models for the characterization of corresponding phosphazene compounds. The redox properties of the complexes3–5 and8–10 as well as of the free cinnamonitrile2 and the free substituted cyclophosphazene1 have been investigated by cyclic voltammetry (CV) and controlled potential electrolysis (CPE) in aprotic media (THF, CH2Cl2, or NCMe 0.2M [NBu4][BF4]), at Pt electrodes. Cathodic processes have been detected only when the unsaturated C=C bond of the cinnamonitrile group is uncoordinated: hence, for compounds1. 4. and9. they are irreversible occur at potentialsE p red ca. –1.3 to ca. –1.9V vs SCE which are less cathodic than that exhibited by the free cinnamonitrile (2:E p red ca. –2.0 V vs SCE), and are believed to be centered at the electron-acceptor empty * (C=C) orbital of each of the cinnamonitrile groups present in the molecule. Anodic processes are displayed only by complexes3. 5. 8. and10 with at least one Pt(0) site: they are irreversible, conceivably centered at such a metal center, and occur at potentials (E p bv ca. 0.7 1.2 V vs SCE) which are dependent on the electronic effects of the ligands, in particular the strong electron-withdrawing ability of the cyclophosphazene group. Complex10 undergoes dissociation in NCMe to form9 and possibly solvated [Pt(PPh3)2] species which adsorb at the electrode surface. No evidence for any redox process centered at the phosphazene ring has been found.Presented at the 1st Italian Workshop on Cyclo- and Poly(phosphazene) Materials, February 15–16, 1996, at the CNR Research Area in Padova, Italy.  相似文献   

5.
Reactions of cationic iridium(I)-COD (COD = 1,5-cyclooctadiene) complexes, [Ir(COD)(PhCN)(PPh3)]ClO4 (1), [Ir(COD)(PPh3)2]ClO4 (2) and [Ir(COD)(PhCN)2]ClO4 (3) with nitriles under H2 catalytically produce primary, secondary and tertiary amines. Hydrogenation of nitriles (RCN) gives HCl salts of amines (RCH2NH2HCl, (RCH2)2NH HCl) in CH2Cl2. Secondary and tertiary amines seem to be produced by the reactions of RCN with primary and secondary amines, respectively under H2 in the presence of catalysts. The hydrogenation in the presence of1 and2 is homogeneously catalyzed by soluble iridium-PPh3 complexes formed in the reactions of1 and2 with H2 and RCN whereas the hydrogenation in the presence of3 is heterogeneous by metallic iridium powders produced in the reduction of3 by H2.  相似文献   

6.
Rational self-assembly of a flexible ligand 3,3′,4,4′-benzophenonetetracarboxylic acid and d10 transition metal salts in the presence of rigid bidentate ligand 1,10-phenanthroline yields two novel helical coordination polymers with different structural motifs; i.e., [Zn(H2bbtc)(phen)2 · 2H2O] n (1) and [Cd2(bbtc)(phen)4 · 2.25H2O] n (2) (H4bbtc = 3,3′,4,4′-benzophenonetetracarboxylic acid, phen = 1,10-phenanthroline), under solvothermal condition. One is hydrogen bonded and π–π stacked together into a network, and the other is a covalently coordinated 3D framework. The coordination polymers were characterized by FT-IR, UV/VIS and fluorescent spectroscopy, single crystal X-ray diffraction, elemental analysis and differential thermal analysis/thermogravimetry (DTA/TG). The most intriguing structural feature is that each complex exhibits novel helical-spaced chains by reason of two different ligands coordinating to the metal centers. Additionally, compounds 1 and 2 showed good fluorescence properties compared to the free ligands.  相似文献   

7.
A series of novel 2-aryl1-4-bromothiophenes (2a–f), biarylthiophenes with non-identical aryl groups (3a–e) and biarylthiophenes with identical aryl groups (4a–f) were synthesized in moderate to excellent yields by using different arylboronic acids in a Suzuki–Miyaura cross-coupling reaction. The experimental results showed that the use of K2CO3 as base resulted in moderate yields compared with that of good yields obtained upon using K3PO4. The highest yield obtained using K3PO4 was 82% for 2, 4-bis (4-chlorophenyl) thiophene (4d). The synthesized compounds in the present study were examined for their biofilm inhibition and hemolysis assay. Among all compounds 2, 4-bis (4-methoxyphenyl) thiophene (4b) was found to strongly inhibit the formation of bacterial biofilm against E. coli. The compound 4b exhibited higher inhibition (80.92%) compared with the standard Rifampicin with 97.43% inhibition. The compound 2, 4-bis (4-chlorophenyl) thiophene (4d) displayed strong anti-biofilm activity with its ability to prevent the formation of Pasteurell amultocida biofilm at the percent inhibition of 74.53%. In addition, 2f showed the highest percentage hemolysis 16.0% compared with that of the standard Triton-X-100. 3  相似文献   

8.
The two-step electrochemical synthesis of chalcogeno derivatives ArEPh (1) and ArEEAr (3) resulting from the oxidation of ArE (2) (AR = 4 – NCC6H4, 1-naphthyl, 2-quinolyl; E = S, Se, Te) can be conveniently carried out in MeCN, by reduction of an aryl halide (ArX) in the presence of electrogenerated PhE or E2 2– anions (SRN1 substitution reaction). To circumvent the disadvantages connected with the use of a divided cell equipped with degradable membranes, a method based on a beaker-type cell has been developed. Thus, the synthesis of substituted compounds1 and3 can be carried out in an undivided cell equipped with a magnesium anode, if a fluoride salt, such as Et4NF.2H2O is purposely added before electrolysis (for3) or after the first step (for1). Under such conditions, the yields are competitive with those obtained in a divided cell.  相似文献   

9.
Two inorganic-organic-type, heat-resistant, thermosetting polyimides,Va andVb, have been synthesized by the reaction of maleic anhydride with different-melting, isomeric tris(4-aminophenoxy)tris(phenoxy)cyclotriphosphazeneIa andIb, respectively, followed byin situ cyclodehydration and thermal polymerization at 230±2°C for 1.5 h and 285±2°C for 0.5 h. Dynamic thermogravimetric analysis (TGA) demonstrated that polymers prepared under identical conditions from isomeric trisamine were thermally stable up to 350°C and showed char yield in the range of 71 to 75% in nitrogen at 800°C and 71% in air at 700°C. Isothermal TGA analysis of polymerVb on heating at 260°C in air for 200 h showed a weight loss of 5%. Thermomechanical analysis (TMA) and torsional braid analysis (TBA) of the two polymers,Va andVb, showed a glass transition temperature (T g) of 335 and 354°C, respectively. This study demonstrated that two polymers prepared under similar conditions from different-melting, isomeric cyclotriphosphazene monomers can have different characteristics.  相似文献   

10.
New copolymers of thiophenes containing azobenzene moieties in the side chain, 3-((((((4-phenyl)azo)phenoxy)ethyl)triethoxy)oxy)-4-methylthiophene/3-methyltetra (oxyethylene)oxy-4-methylthiophene (CP1) and 3-((((((4-phenyl)azo)phenoxy)ethyl) triethoxy) oxy)-4-methylthiophene/3-dodecylthiophene (CP2), were synthesized from 3-bromo-4-methylthiophene. These copolymers were characterized by 1H-NMR spectroscopy, and their thermal, optical, and electrochemical properties were determined by thermogravimetric analysis, differential scanning calorimetry, absorption spectroscopy, and cyclic voltammetry. CP1 possesses higher degree of conjugation and azobenzene content than CP2, and its structure is more regio-regular. Besides, CP1 exhibited a higher glass transition temperature (T g = 35 °C, T 5 = 225 °C) and a lower thermal stability than CP2 (T g = 13 °C, T 5 = 307 °C). Both copolymers showed a similar solvatochromic behavior when they were dissolved in chloroform and mixtures chloroform:methanol.  相似文献   

11.
Summary Single-site calcium initiators containing chelating tmhd (H-tmhd = 2,2,6,6-tetramethylheptane-33-dione) ligands [(THF)Ca(tmhd)]2[-N(SiMe3)2](-tmhd) (2) and [(THF)Ca(tmhd)]2[-OCH(Me)Ph](-tmhd) (3) have been synthesized and applied for the ring-opening polymerization of L-lactide and -caprolactone. Both 2 and 3 were highly reactive and promoted a fast polymerization of L-lactide and -caprolactone to high monomer conversions under mild conditions (THF as a solvent, room temperature). More importantly, results showed that the ring-opening polymerizations of lactides and lactones initiated by either 3 or 2 in the presence of equivalent 2-propanol are living, to provide polymers and block copolymers of controlled molecular weights and tailored end-groups. The polymerizations were first-order in monomer up to high conversions, in which the in situ initiating system 2/2-propanol revealed no induction period and much faster polymerization kinetics as compared to 3.  相似文献   

12.
Summary 3,4-Di-(2'-hydroxyethoxy)-4'-nitrostilbene (2) were prepared by the reaction of 2-iodoethanol with 3,4-dihydroxy-4'-nitrostilbene (1). Diol 2 was condensed with 2,4-toluenediisocyanate and 3,3'-dimethoxy-4,4'-biphenylenediisocynate to yield polyurethanes 3 and 4 containing the NLO-chromophore 3,4-dioxy-4'-nitrostilbene. Polymers 3 and 4 were soluble in common organic solvents such as acetone and DMSO. T g value of the resulting polymers was in the range of 109–114°C. Electrooptic coefficient (r33) of the poled polymer films were in the range of 20–25 pm/V at 633 nm. Polymers 3 and 4 showed a thermal stability up to 300°C in TGA thermograms, which is acceptable for NLO device applications. Received: 29 September 1999/Revised version: 19 November 1999/Accepted: 25 November 1999  相似文献   

13.
Summary 1-(2',2',3'-Tricyano-3'-carbomethoxycyclopropyl)-3,4-di-2'-hydroxyethoxybenzene (4) was prepared by the reaction of bromomalononitrile with methyl 3,4-di-(2'-hydroxyethoxy)benzylidenecyanoacetate (3). Diol 4 was condensed with 3,4-toluenediisocyanate and 3,3'-dimethoxy-4,4'-biphenylenediisocynate to yield polyurethanes 5 and 6 containing multicyanocyclopropane functionalities in the pendant group. The resulting polymers 5 and 6 were soluble in common organic solvents and the inherent viscosities were in the range of 0.25–0.30 dL/g. Polyurethanes 5 and 6 showed a thermal stability up to 300°C in TGA thermograms. Solution-cast films showed T g values in the range of 100–130°C and piezoelectric coeffcients (d31) of the poled polymer films were 1.8–2.0 pC/N, which are acceptable for piezoelectric device applications. Received: 14 December 2000/Accepted: 22 January 2001  相似文献   

14.
N 4-hydroxyethyl-pyridinealdehyde thiosemicarbazone (HL, 1) as a tridentate Schiff base has been synthesized by 1:1 reaction of S-methyl-3-((pyridyl)methyl) dithiocarbazate and 2-aminoethanol. Complexes [Cd(HL)2](NO3)2 (2), [Cd(HL)I2] (3), [Cd(HL)Cl2] (4), [Cu(HL)2](NO3)2 (5) and [Cu(HL)Cl2] (6) have been obtained and characterized by elemental analyses, molar conductivities, and spectroscopic studies. The ligand molecule binds the metal ion using pyridyl nitrogen, azomethine nitrogen and the sulfur atoms. The crystal structure analysis of 3 has been determined and showed to be a distorted square pyramidal geometry complex. The inter- and intramolecular interactions give rise to a supramolecular network. Compounds 2, 3, 5 and 6 were assayed for their bioactivities against selected pathogens. Copper(II) complexes 5 and 6 showed antimicrobial activities against Gram-positive (Bacillus anthracis) and Gram-negative (Pseudomonas aeruginosa and Yersinia pseudotuberculosis) bacteria, complexes 24 showed antimicrobial activities against Bacillus atrophaeus, while the ligand itself showed antimicrobial activities against Escherichia coli and Y. pseudotuberculosis.  相似文献   

15.
The use of (tetrakis(4-hexylphenyl)porphyrinato)Fe(II) in polymerization reactions with bidentate ligands such as 9,10-diisocyanoanthracene and 1,4-diisocyanobenzene led to well-defined stacked polymers1 and2 which are still soluble in common organic solvents such as chloroform, dichloromethane, and tetrahydrofurane. They have been completely characterized by1H-NMR and UV/vis spectropscopy in solution, even allowing end-group analysis for determination of the average degree of polymerization, yieldingn=10 andn=5 for1 and2, respectively. Mößbauer and IR spectroscopy further established the strong Fe-CN bonding reflected by very small isomer shifts and quadrupole splittings (E Q0.2 mm s–1) and a large decrease in the IR stretching frequency (v CN60 cm–1). The axially stacked polymers exhibit semiconducting properties only upon doping.Presented at the 5th International Symposium on Macromolecule-Metal Complexes (MMV), Summer 1993 in Bremen, Germany.  相似文献   

16.
Summary p-(2,2,3-Tricyano-3-carbomethoxycyclopropyl)phenoxyethyl acrylate (5a) and p-(2,2,3-tricyano-3-carbomethoxycyclopropyl)phynoxyethyl methacrylate (5b) were prepared by the reactions of bromomalononitrile with methyl p-(2-acryloyloxyethoxy)benzylidene-cyanoacetate (4a) and methyl p-(2-methacryloyloxyethoxy)benzylidenecyanoacetate (4b), respectively. Monomers 5a and 5b were polymerized with free-radical initiators to obtain the polymers with multicyanocyclopropane functionalities in the pendant group. The resulting polymers 6a and 6b were soluble in acetone and the inherent viscosities were in the range of 0.20–0.25 dL/g. Solution-cast films showed T g values in the range of 130–150°C and piezoelectric coeffcients (d31) of the poled films were 1.5–1.6 pC/N, which are acceptable for piezoelectric device applications. Received: 28 April 2000/Accepted: 26 June 2000  相似文献   

17.
Summary Methyl 2,4-bis-(2'-hydroxyethoxy)benzylidenecyanoacetate (3) was prepared by hydrolysis of methyl 2,4-bis-(2'-vinyloxyethoxy)benzylidenecyanoacetate (2). Diol 3 was condensed with 2,4-toluenediisocyanate, 3,3'-dimethoxy-4,4'-biphenylene-diisocyanate, and 1,6-hexamethylenediisocyanate to yield polyurethanes 4–6 containing the NLO-chromophore 2,4-dioxybenzylidenecyanoacetate. The resulting polyurethanes 4–6 were soluble in common organic solvents such as acetone and DMF. Polymers 4–6 showed a thermal stability up to 280°C in TGA thermograms with T g values obtained from DSC thermograms in the range of 66–114°C. The SHG coefficients (d33) of poled polymer films were around 7.8 × 10−9 esu. Received: 25 February 2002/ Revised version: 25 March 2002/ Accepted: 29 March 2002  相似文献   

18.
The triorganotin carboxylates of 2-mercapto-4-methyl-5-thiazoleacetic acid (1), R3Sn[O2CCH2- (C4H3NS)S]SnR3 (R=Me 2, n-Bu 3, Ph 4 PhCH2 5), have been synthesized and characterized by IR, 1H and 13C NMR spectroscopy. Among them, complexes 2 and 4 were also characterized by X-ray crystallography diffraction analysis, which revealed that both 2 and 4 showed a one-dimensional polymeric structure in which the geometries of the tin atoms are different: one was a distorted tetrahedron and the other was trigonal bipyramidal with the axial positions occupied by oxygen atoms.  相似文献   

19.
The reaction of isatin-3-thiosemicarbazone (ITC, 1) or isatin-3-semicarbazone (ISC, 2) with nitrato bis(triphenylphosphine)copper(I) gave the four coordinate copper(I) complexes [Cu(PPh3)2(ITC)]NO3 (3) and [Cu(PPh3)2(ISC)]NO3 (4). The synthesized complexes were characterized by FT-IR, UV–VIS, Raman and elemental analysis. The crystal structure of 3 was investigated by single crystal X-ray diffraction. The ITC coordinates to the copper(I) ion in a bidentate fashion via the N(imine) and S atoms which along with two triphenylphosphine ligands form a tetracoordinate complex. The complex has a distorted tetrahedral coordination environment. Crystal data at 150.0 K: space group P21/c with a=12.5777(4), b=15.2062(5), c=21.9057(7) Å, β=95.628(3)o, Z=4, R 1=0.049.

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20.
Dominicalure 1 (9a) and dominicalure 2 (9b), were synthesized by esterification of ,-unsaturated acids4a and4b with (S)-(+)-2-pentanol (8). The key step was the asymmetric reduction of 3-penten-2-one (5) to give the chiral intermediate6, which, upon diimide reduction, DNB derivatization, recrystallization, and hydrolysis, yielded8 in 63% ee. Acids4a and4b were prepared in a simple and efficient three-step synthesis with an overall yield of 54% and 62%, respectively, in stereoisomerically pure form.  相似文献   

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