HETEROAROMATIC POLYMERS—HIGH TEMPERATURE POLYPYRROLONES DERIVED FROM 2,6-BIS(3'''',4''''-DIAMINOPHENYL)-4-BIPHENYLPYRIDINE AND VARIOUS AROMATIC DIANHYDRIDES

A new type of aromatic tetraamine containing biphenyl moiety in the side chain was synthesized via a modified Chichibabin's reaction.3-Nitro-4-acetamidoacetophenone was reacted with 4-phenyl benzaldehyde in the presence of ammonium acetate to obtain 2,6-bis(3',4'-diaminophenyl)-4-biphenyl pyridine(DPPA).A series of polypyrrolones(PPys) were prepared using tetraamine and various aromatic dianhydrides via a two-step cyclization procedure.All the PPys show excellent high temperature stabilities with the initial decomposition temperatures of 530-549℃ and residual weight ratio of 49%-80% at 750℃ in nitrogen.The polymers exhibit no apparent glass transition temperatures(T_gs)except PPy-1 (T_g=327℃),which is derived from tetraamine DPPA and 2,2-bis[4-(3',4'-dicarboxyphenoxy)-phenyl]propane dianhydride (BPADA).In addition,the polymers have acceptable mechanical properties with the tensile strength of 65-94 MPa.The PPy films show excellent hydrolysis-resistance in alkaline aqueous medium and could maintain most of the properties even after boiling in 10% aqueous sodium hydroxide solution for a week.     

Investigation of the interaction of DNA and neutral red by?uorescence spectroscopic analysis

The binding characteristics of neutral red (NR) with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition (SVD) was used to evaluate the number of spectral species in the drug-DNA binding process, and then the intrinsic binding constant of 1.6 104 in base pairs and the binding site number of 0.97 were obtained from the Scatchard plot.     

Synthesis, Structure and DFT Investigation into a Copper(II) Compound Consisting of 4,7-diphenyl-1,10-phentheanthroline

1 INTRODUCTION terested in the unique effects associated with substituents at 4- and 7-positions of the phenan- The coordination chemistry of 1,l0-phenanthroline throline ring. Thus, when phenyl groups are present, and its derivatives has captured the attention of che- the absorptivities of the CT transitions are increased mists for years. The reports on biological importance[1~4], markedly due to the extension of the dipole moment supramolecular chemistry[5], electronic spectra[6], conne…     

FINITELY GENERATED COMMUTATIVE ARCHIMEDEAN SEMIGROUPS

In this work commutative Archimedean finitely generated semigroups are characterized in terms of ideal extensions.     

Structure of Cytochromec and Its Platinum-modified Derivatives by Fourier Transform Infrared Spectroscopy

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Studies on the Mechanism of Methyl Methacrylate Polymerization Initiated by Volatile and Nonvolatile Products of Methyl Methacrylate Plasma

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Structure of BaGd2（MoO4）4 Crystal

The title compound belongs to monoclinic,space group C2/c with a=5.2694(1),b=12.6659(4),c=19.4108(2) ,β=91.504(2)°,V=1295.06(5) 3,Z=4 and Dc=5.599 g/cm3. The structure of BaGd2(MoO4)4 contains a MoO4 tetrahedron,a distorted GdO8 polyhedron,and Ba2+ ions in a tenfold coordination. The GdO8 polyhedra are linked together through edge-sharing to give a two-dimensional Gd layer. The MoO4 tetrahedra connected to the Gd atoms are capped up and down the Gd layer through common oxygen apices,thus forming a new Gd-Mo layer. Finally,the Gd-Mo layers are held together through bridging BaO10 polyhedra to form a three-dimensional framework. Since the Ba-μ3-O bond has a large average distance of 2.888 ,this structural characteristic will result in a cleavage along the (001) plane.     

Synthesis and Crystal Structural Characterization of a Thiosemicarbazone Derived from 4-Acylpyrazolone

1 INTRODUCTION Pyrazol-5-one derivatives form an important class of organic compounds due to their structural che- mistry and biological activities as analgesic, antipy- retic, anti-inflammatory and hyperglycemic agents[1～4]. Even the simplest pyrazol-5-one derivatives like antipyrine and amidopyrine are widely used in anal- gesic medicine[5, 6]. On the other hand, thiosemicar- bazones, especially heterocyclic thiosemicarbazones, have been the subject of extensive investigations be- cause…     

Synthesis and Crystal Structure of N, N'''''''',N''''''''-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) Amine

1 INTRODUCTION Schiff’s bases are well known ligands representedby many bi-, tri-, tetra-, and hexa-dentate example-es[1], but heptadentate ligands are relatively rare[2, . 3]We have reported a copper complex of tetradentateSchiff’s bases[4]…     

Synthesis and Crystal Structure of Ethyl 2,7,7-Trimethyl-4-(4''''-methylphenyl)- 5-oxo-1,4,5,6,7,8-hexahydroquinoline-3- carboxylate in Aqueous Medium

1 INTRODUCTION The 1,4-dihydropyridines (1,4-DHPs) are biologi- cally interesting compounds and have been developed extensively in pharmacology. 1,4-DHP derivatives are used therapeutically in the treatment of cardio- vascular disorders, especially hypertension and coro- nary heart disease such as angina pectoris, atheros- clerosis, etc. The DHPs have emerged as one of the most important classes of drugs for the treatment of gastrointestinal disease, Raynaud?s disease, pulmonary hyper…