AROMATIC AND HETEROCYCLIC DINITRILES AND THEIR POLYMERS ⅪⅤ.STUDY ON THE CATALYSTS OF THE POLYMERIZATION OF AROMATIC NITRILES

Various catalysts for the polymerization ot aromatic nitriles were investigated. It was found that Lewis acid-metal is a preferable catalyst system for the polymerization of aromatic nitriles, and the polymerization rate is about 10 times faster than Lewis acid alone. The polymerization rate of benzonitrile catalyzed by Lewis acid and different metals was measured, and the activity of metals was in the following decreasing order ,magnesium, zinc, sodium, calcium. Furthermore, the polymerization of benzonitrile catalyzed by different Lewis acid and zinc was also investigated.

AROMATIC AND HETEROCYCLIC NITRILES AND THEIR POLYMERS ⅩⅥ. THE POLYMERIZATION KINETICS OF 4, 4′-BIPHENYLDICARBONITRILE CATALYZED BY LEWIS ACID-METAL SYSTEM

The polymerization kinetics of 4, 4′-biphenyldicarbonitrile using cuprous chloride-zinc system as catatyst was investigated. the concentration of unreacted cyano group was measured by infrared spectroscopic analysis using potassium ferricyanide as the internal reference. It was found that the polymerization rate is directly proportional to the concentrations ofcyano group, cuprous chloride and zinc, and the activation energy of the polymerization is as Tow as 18.4 KJ/mol. In addition, the other kinetics parameters were obtained and discussed.

AROMATIC AND HETEROCYCLIC NITRILES AND THEIR POLYMERS ⅩⅦ. THE POLYMERIZATION KINETICS OF CYANOPYRIDINES AND CHARACTERIZATION OF THE FORMED POLYMER

The polymerization rates of three cyanopyridines catalyzed by cuprous chloride-zinc system are measured, and the structure of the formed polymer is also determined. Compared with aromatic nitrile, cyanopyridines polymerize faster and form polyconjugated polymer with skeleton—（C=N）—;instead of triazine structure. This chain-polymer possesses semiconductive property, and can be converted into conductive material by thermal treatment. In addition, the polymerization kinetics of 3-cyanopyridine catalyzed by 3-cyanopyridinium perchlorate is investigated. It is found that the polymerization rate is directly proportional to the concentrations of monomer and catalyst, and the activation energy of the polymerization is 103.1 KJ/mol.

Ammoxidation of Substituted Toluenes on Silica-Supported VPO Catalysts

The ammoxidation of substituted toluenes to their corresponding nitriles over silica-supported vanadium phosphorus oxide (VPO/SiO2) catalysts has been studied. the effects of carrier silica, the addition of phosphorus, the substituents and the loadings have been discussed. Compared with unsupported VPO, the VPO/SiO2 catalysts have higher catalytic activity for ammoxidation of substituted toluenes and much lower reaction temperature. XRD shows that vanadium phosphorus oxides exist as amorphous phase and disperse to a high degree on the silica surface in 10%loading catalyst. When the loadings are over 10%, the crystalline α-VOPO4 would emerge, which would decrease the yield and selectivity. Additional phosphorus can form composite oxides with vanadia and play concerted catalytic function, which increase the selectivity of nitriles remarkably. Different substituents or same substituents on different positions have different influences because of the variant electronic stability of intermediates, the hindered accessibility of methyl group or the chemisorption state of the substrate molecule on the electrophilic catalyst surface.

Synthesis, structure, and catalytic activity of rare-earth metal amides with a neutral pyrrolyl-functionalized indolyl ligand

The reactions of neutral pyrrolyl-functionalized indole with rare-earth metal amides [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 produced the rare-earth metal complexes [(Me3Si)2N]2RE([η1:μ-η2-3-(2-(N–CH3)C4H3NCH=N–CH2CH2)C8H5N])(μ-Cl)Li(THF)(RE = Er, Y) having indolyl ligand η1 bonded to rare-earth metal ion and η2 bonded to lithium ion. The catalytic activities of these lanthanide amido complexes for addition of terminal alkynes to aromatic nitriles were explored. Results reveal that these complexes displayed a good catalytic activity for the addition reaction under mild conditions.