Paweł Maksimowski

Polarographic studies of CpTiCl2(OC6H4X-p)/MAO and EPR studies of CpTiCl2(OC6H4X-p)/MAO/styrene systems

Cyclopentadienyl-titanium complexes containing OC6H4X ligands (X=NO2, Cl, H, C(CH3)3, OCH3) were synthesized. The “X” substituents at the phenoxy ligands have different electron donor properties, which are described by Hammett’s factors. Mixtures of CpTiCl2(OC6H4X-p) and MAO were investigated by polarography. The amount of Ti(III) ions have been noticed. EPR spectra were recorded for mixtures of CpTiCl2(OC6H4X-p) with MAO and styrene. The shape and the parameters of the EPR spectra were found to be related to the nature of OC6H4X-p ligands.

4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,903,11]dodecane Synthesis

4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,903,11]dodecane (TEX) was obtained by nitrolysis of 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine reaction using a mixture of fuming nitric acid and concentrated sulfuric acid. The optimal process temperature was 54–56°C. The yield of the synthesis depends inter alia on the rate the reactants are introduced into the reaction medium and on the time of conditioning of the reaction mixture. A maximal yield of ca. 40% was achieved at the reactant addition time of 2 h and conditioning time of 2 h. None of the other nitrating mixtures examined proved superior to the conventional nitrating mixture. The product was examined by high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC) techniques and the results are reported.

Hexene-1 isomerization on NaNp/CpTiCl3/Al2O3SiO2 (Np-naphthenide; Cp-cyclopentadienyl) system

NaNp/CpTiCl(3)/Al(2)O(3)SiO(2) (Cp=cyclopentadienyl; Np=napthenide anion) systems are new catalysts active in the C=C hexene-1 bond isomerization reaction. Their activity depends on amount of titanium[III] hydride surface complexes and the support Lewis acidity. As results showed, all these properties are a function of the Al(2)O(3)-SiO(2) gels composition. The highest yields were obtained for the 90 and 100 wt.% Al(2)O(3) catalysts (Lewis acidity) and for the 10 and 60 wt.% Al(2)O(3) catalysts (amount of Ti[III]+Lewis acidity).

CpTiCl3-alumina-silica system reduced with NaNp

The system CpTiCl3/Al2O3−SiO2 (0–100 wt.% of Al2O3), (Cp=cyclopentadienyl) was reduced with a tenfold excess of NaNp (Np=naphthalene) in THF and argon atmosphere at room temperature. Only titanium(IV) and titanium(III) compounds were found by the polarographic method in the systems studied. The amount of the titanium(III) compounds is influenced by the acidity of supports.