A strategy for synthesis of ion-bonded supramolecular star polymers by reversible addition-fragmentation chain transfer (RAFT) polymerization

We have developed a novel strategy for the preparation of ion-bonded supramolecular star polymers by RAFT polymerization. An ion-bonded star supramolecule with six functional groups was prepared from a triphenylene derivative containing tertiary amino groups and trithiocarbonate carboxylic acid, and used as the RAFT agent in polymerizations of tert-butyl acrylate (tBA) and styrene (St). Molecular weights and structures of the polymers were characterized by H-1 NMR and GPC. The results show that the polymerization possesses the character of living free-radical polymerization and the ion-bonded supramolecular star polymers PSt, PtBA, and PSt-b-PtBA, with six well-defined arms, were successfully synthesized.

Synthesis and anti-HIV-1 activities of novel podophyllotoxin derivatives

In order to explore the range of biological activities of the podophyllotoxin compound class, a novel series of derivatives of podophyllotoxin, which were conjugates containing stavudine and different structural podophyllotoxin analogues, were designed, s

Synthesis and anti-HIV-1 activity of S-dihydro(alkyloxy)benzyloxypyrimidine derivatives

Several 2-heteroaryl-, 2-heteroarylcarbonylmethyl-, 2-arylcarbonylmethyl, and 2-arylethyl derivatives of S-dihydro(alkyloxy)benzyloxypyrimidines have been synthesized and the anti-HIV activities of these compounds were tested in C8166 cell and against RT

Synthesis and Anti-Human Immunodeficiency Virus Type 1 Activity of (E)-N-Phenylstyryl-N-alkylacetamide Derivatives

A series of (E)-N-phenylstyryl-N-alkylacetamides, 5, were synthesized by direct reduction-acetylation of beta-arylnitroolefins, followed by N-alkylation. The title compounds were characterized by H-1-NMR, EIMS and IR analysis. All the synthesized compound

Synthesis of Zidovudine Derivatives with Anti-HIV-1 and Antibacterial Activities

Twelve novel zidovudine derivatives were prepared by modifying 5 '-hydroxyl group of sugar moiety (1-8) and 5-methyl group of thymidine nucleus (9-12) and characterized spectrally. The compounds were evaluated for anti-HIV-1, antitubercular and antibacter

Highly efficient red electroluminescent polymers with dopant/host system and molecular dispersion feature: polyfluorene as the host and 2,1,3-benzothiadiazole derivatives as the red dopant

By selecting polyfluorene as the polymer host, choosing 2,1,3-benzothiadiazole derivative moieties as the red dopant units and covalently attaching 0.3 mol% of the dopant units to the side chain of the polymer host, we developed a novel series of red electroluminescent polymers of dopant/host system with molecular dispersion feature. Their EL spectra exhibited predominant red emission from the dopant units because of the energy transfer and charge trapping from the polymer backbone to the dopant units. The emission wavelength of the polymers could be tuned by modifying the chemical structures of the dopant units.

White electroluminescence from a single-polymer system with simultaneous two-color emission: Polyfluorene as blue host and 2,1,3-benzothiadiazole derivatives as orange dopants on the side chain

Four single polymers with two kinds of attachment of orange chromophore to blue polymer host for white electroluminescence (EL) were designed. The effect of the side-chain attachment and main-chain attachment on the EL efficiencies of the resulting polymers was compared. The side-chain-type single polymers are found to exhibit more efficient white EL than that of the main-chain-type single polymers. Based on the side-chain-type white single polymer with 4-(4-alkyloxy-phenyl)-7-(4-diphenylamino-phenyl)-2,1,3-benzothiadiazoles as the orange-dopant unit and polyfluorene as the blue polymer host, white EL with simultaneous orange (lambda(max) = 545 nm) and blue emission (lambda(max) = 432 nm/460 nm) is realised. A single-layer device (indium tin oxide/poly(3,4-ethylenedioxythiophene)/polymer/Ca/Al) made of these polymers emits white light with the Commission Internationale de l'Eclairage coordinates of (0.30,0.40), possesses a turn-on voltage of 3.5 V, luminous efficiency of 10.66 cd A(-1), power efficiency of 6.68 lm W-1, and a maximum brightness of 21240 cd m(-2).

Hydrogen-deuterium exchange reactions of cis- and trans-cyclopropane derivatives with D2O and CD3OD in the gas phase

Gas-phase hydrogen-deuterium (H/D) exchange reactions involving four isomeric cyclopropane derivatives were investigated under chemical ionization (CI) conditions, using D2O and CD3OD as reagent gases. There are abundant ions at [M + 1](+), [M + 2](+) and [M + 3](+) in the D2O and CD3OD positive-ion CI mass spectra of the two isomer pairs 1, 2 and 3, 4, Their CI mass spectra are identical with each pair, and so are the collision-induced dissociation (CID) spectra of ions [M + 1](+), [M + 2](+) and [M + 3](+) of each of the two isomer pairs. The CID spectra of [M + 1](+) ions indicate that they have common D/H exchange reactions within each pair, which take place between molecular ions and deuterium-labeling reagents to form the [M - H + D](+) ions. Those of their [M + 2](+) ions show that they have common D/H exchange reactions within each pair, which form the [M-d1 + H](+) ions. Those of their [M + 3](+) ions show that they have common D/H exchange reactions within each pair, which take place between the [M-d1] and deuterium-labeling reagents to produce [Md-2 + H](+) for the isomer pair 1, 2 and [M-d1 + D](+) for the Isomer pair 3, 4. The number and position, and active order of the active hydrogen atoms of the isomer pairs 1, 2 and 3, 4 were determined. Copyright (C) 2000 John Wiley & Sons, Ltd.

H/D exchange reaction of cyclopropane derivatives in the ion system of CD3OD

The fragmentation properties of the product ions [M + 1](+), [M + 2](+) and [M + 3](+) formed by ion-molecule reaction of four cyclopropane derivatives with the ion system of CD3OD were investigated by using collision-induced dissocation technique. The experiment results indicated that the product ions were produced via the H/D exchange reaction between reactants and reactive reagent ions of CD3OD. There are two exchangable hydrogen atoms on the ring of compounds 1 and 2, and only one for compound 3 and 4.

Synthesis and properties of three tris(1,10-phenanthroline) ruthenium (II) derivatives

Three new asymmetrical ruthenium (II) complexes: [Ru(phen)(2){phen-NHCO(CH2)(4)Br}](PF6)(2), [Ru(phen)(2){phen-NHCO(CH2)(5)Br}](PF6)(2) and [Ru(phen)(2){phen-NHCO(CH2)(10)Br}](PF6)(2) were synthesized, which were confirmed by the technique of FT-IR, H-1 NMR and ESI-MS. The electrochemical and fluorescent properties of three Ru (II) complexes were investigated with cyclic voltammetry and fluorometry.

Four novel screw-like tris(1,10-phenanthroline) ruthenium(II) bishexafluorophosphate derivatives

Four novel screw-like Ru(II) complexes, tris(5-lauramide-1,10-phenanthroline)Ru(II) bishexafluorophosphate, tris(5-myristamide-1,10-phenanthroline)Ru(II) bishexafluorophosphate, tris(5-palmitamide-1,10-phenanthroline)Ru(II) bishexafluorophosphate and tris (5-stearamide-1,10-phenanthroline)Ru(II) bishexafluorophosphate have been efficiently synthesized. They are confirmed by the techniques of IR, H-1 NMR, H-1-H-1 COSY and ES-MS. Also, their electrochemistry, fluorescence and electrochemiluminescence are reported.

Ion-molecule reactions of cis- and trans-cyclopropane derivatives with methane, acetone and vinyl acetate under chemical ionization conditions

Ion-molecule reactions of four isomeric cyclopropane derivatives were investigated under chemical ionization(CI) conditions, using methane, acetone and vinyl acetate as reagent gases, The methane positive-ion CI mass spectra of each of two isomer pairs 1,2 and 3,4 are identical, and so are the collision-induced dissociation (CTD) spectra of the protonated molecules of each of the two isomer pairs, The protonation reactions for the isomer pairs 1,2 and 3,4 occurred on the sites of the carboxyl groups and the R groups, respectively, Differences between isomers 1 and 2 are observed in their acetone (A) positive-ion CI mass spectra and in the CID spectra of their adduct ions ([M+H+A](+)), The adduct ions of compounds 2, 3 and 4 with protonated acetone and with protonated acetone dimer are observed in their CI mass spectra, However, only the adduct ions of compound 1 with protonated acetone appear in its CI mass spectrum, The protonated dimers of each of the four compounds are found in their vinyl acetate positive-ion CI mass spectra, and the CID spectra of these dimers for isomers 1 and 2 can also reflect their stereostructural difference. (C) 1998 John Wiley & Sons, Ltd.

Synthesis and characterization of soluble polyimides from 1,1-bis(4-aminophenyl)cyclohexane derivatives

A series of novel aromatic diamines (1-3) containing kinked cyclohexylidene moieties was synthesized by a reaction of excess aniline and corresponding methyl-substituted cyclohexanone derivatives. The structures of (1-3) were identifield by H-1 NMR, C-13 NMR, and FT-IR. The polymers were synthesized from the obtained diamines and various aromatic dianhydrides by the conventional polycondensation reaction followed by chemical imidization as well as high-temperature one-step polymerization. The inherent viscosities and weight-average molecular weights of the resulting polyimides were in the ranges of 0.55-1.58 dL/g and (7.4-15.2) x 10(4) g/mol, respectively. The prepared polyimides showed excellent thermal stabilities and good solubility. All polymers were readily soluble in common organic solvents such as tetrahydrofuran, chloroform, tetrachloroethane, etc., and the glass transition temperatures were observed at 290-372 degrees C.