N,N&rsquo / -bis(ferrocenylmethylene)ethylenediamine was prepared from the reaction of ferrocenecarboxaldehyde and ethylenediamine and characterized by IR, Raman, 1H and 13C-NMR spectroscopy. The electrochemical behaviour of this ligand was also studied for the first time by cyclic voltammetry. Diferrocenyl diimine ligand was used in the thermal substitution of 1,5-cyclooctadiene in Cr(CO)4(2:2-1,5-cyclooctadiene) at 38&deg / C in toluene for two hours to form the tetracarbonyl[N,N&rsquo / -bis(ferrocenylmethylene)ethylenediamine]chromium(0), [Cr(CO)4(BFEDA)]. This complex was succesfully isolated and crystallized from its 1:1 toluene/dichloromethane solution and characterized by elemental analysis, MS, IR, 1H, 13C-NMR spectroscopy. Electrochemical behaviour of the complex was also studied by cyclic voltammetry and the mechanism of electrode reaction was investigated by in-situ UV-VIS and IR spectroscopy measurements. This new complex has the iron atom of ferrocene unit in conjugation with the chromium metal center and, therefore, shows an electronic communication between two metal atoms.

In this study a bidentate ligand containing two ferrocenyl moieties, N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine, was prepared by condensation reaction of ferrocenecarboxyaldehyde and ethylenediamine on refluxing in benzene. The molecule was identified by IR, Raman, UV-Vis, 1H-, 13C-NMR spectroscopies. Then, this bidentate molecule was reacted with tetracarbonyl(bicyclo[2.1.1] hepta-2,5-diene)molybdenum(0). The ligand substitution reaction in toluene yielded the new complex, tetracarbonyl[N,N&acute / -bis(ferrocenylmethylene)ethylenediamine] molybdenum(0). This new complex could be isolated from the reaction solution in the form of orange crystals and fully characterized by elemental analysis, IR, UV-Vis, MS, 1H- and 13C-NMR spectroscopies. As a bidentate ligand, N,N&acute / -bis(ferrocenylmethylene)ethylenediamine binds the metal atom in the two cis positions in the pseudooctahedral geometry of the molybdenum-complex. Electrochemistry of the tetracarbonyl[N,N&acute / -bis(ferrocenylmethylene) ethylenediamine]molybdenum(0) was studied by cyclic voltammetry, chronoamperometry and controlled potential electrolysis combined with the UV-Vis or infrared spectroscopy. One irreversible oxidation and three reversible oxidations were observed in the cyclic voltammogram. Irreversible and a reversible oxidations are attributed to molybdenum and the other two reversible oxidation to iron centers. It is found that the two ferrocene groups started communication with each other after formation of molybdenum-complex.

In this study a bidentate ligand containing two ferrocenyl moieties, N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine, was prepared by condensation reaction of ferrocenecarboxyaldehyde and ethylenediamine on refluxing in benzene. The molecule was identified by IR, Raman, UV-VIS, 1H-, 13C-NMR spectroscopies. Then, this bidentate ligand was reacted with pentacarbonylbis-(trimethyl)silylethyne)tungsten(0). The ligand substitution reaction in dichloromethane yielded the new complex, tetracarbonyl [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) (W(CO)4(BFEDA)). This new complex was isolated from the reaction solution in the form of orange crystals and fully characterized by elemental analysis, IR, UV-VIS, MS, 1H- and 13C-NMR spectroscopies. As a bidentate ligand, [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine] binds the metal atom in the two cis positions in the pseudooctahedral geometry of the tungsten-complex. Electrochemistry of the tetracarbonyl [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) was studied by cyclic voltammetry, and controlled potential electrolysis combined with the UV-VIS spectroscopy. One irreversible oxidation and three reversible oxidations were observed in the cyclic voltammogram. One of these reversible and the irreversible oxidations are attributed to tungsten and the other two reversible oxidations to iron centers. It is found that the two ferrocene groups started communication with each other after formation of tungsten-complex. N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine was also reacted with photogenerated pentacarbonyl(tetrahydrofuran)tungsten(0) complex and the pentacarbonyl [N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) (W(CO)5(BFEDA)) as an intermediate on the route to the tetracarbonyl[N,N&#039 / -bis(ferrocenylmethylene)ethylenediamine]tungsten(0) was isolated from the reaction medium in the form of red crystals and fully characterized by, IR, 1H- and 13C-NMR spectroscopies. The conversion of W(CO)5(BFEDA) to the W(CO)4(BFEDA) in dichloromethane by a ring closure mechanism was observed by IR spectroscopy.

O complexo 1,4-bis(2,6-diisopropilfenil)-acenaftenodiimina-dicloroníquel(II) (1), em combinação com metilaluminoxano (MAO) foi utilizado para polimerizar eteno utilizando altas pressões e temperaturas. Foram investigados os efeitos da pressão de eteno, da temperatura, do tempo de reação e da quantidade de catalisador bem como, as propriedades dos polietilenos sintetizados. Os polietilenos obtidos com o sistema (1)/MAO foram altamente ramificados. As ramificações variaram de metil até hexil ou até mais longas, sem adição de comonômero. Os polietilenos não apresentaram metilas isoladas, apresentando uma grande quantidade de metilas 1,4, metilas 1,5 e metilas 1,6 e cadeias longas. A presença de ramificações foi devido ao mecanismo denominado chain-walking. Os valores de ramificações nos PE foram maiores que 105 e menores que 277 ramificações/1000C. O aumento do número de ramificações foi devido ao aumento na temperatura de polimerização e uma diminuição da pressão de eteno. Os PE obtidos com o sistema (1)/MAO apresentaram peso molecular (Mw) elevado entre 44.000 e 105.000 Daltons e valores de polidispersão de 2,0 a 4,0, dependendo das condições reacionais. O peso molecular dos polímeros diminuiu com o aumento da temperatura de polimerização. / The combination of 1,4-bis(2,6-diisopropylphenyl)-acenaphthenediiminedichloronickel( II) (1) and methylaluminoxane (MAO) was highly active in ethylene polymerization under high pressures and temperatures. Herein we investigated the effects of ethylene pressure, reaction temperature, reaction time and amount of catalyst on polymer properties and reaction performance. The polyethylenes obtained with 1/MAO are highly branched. The branches goes from methyl to hexyl or even longer, and this without comonomer addition. These polyethylenes obtained do not shows isolated methyl groups, but shows 1,4-methyl, 1,5 and 1,6 methyl patterns. The branching was due to the so-called chain-walking mechanism. The branch content, which is in the range 105 to 277 branches/1000 C, increased with the temperature rising or the ethylene concentration decrease. The polyethylenes produced with these system have molecular weight between 44.000 and 105.000 Daltons and polydispersions from 2,0 to 4,0 depending on the reactions conditions. The polymer molecular weight tended to decrease with increasing polymerization temperature.

O complexo 1,4-bis(2,6-diisopropilfenil)-acenaftenodiimina-dicloroníquel(II) (1), em combinação com metilaluminoxano (MAO) foi utilizado para polimerizar eteno utilizando altas pressões e temperaturas. Foram investigados os efeitos da pressão de eteno, da temperatura, do tempo de reação e da quantidade de catalisador bem como, as propriedades dos polietilenos sintetizados. Os polietilenos obtidos com o sistema (1)/MAO foram altamente ramificados. As ramificações variaram de metil até hexil ou até mais longas, sem adição de comonômero. Os polietilenos não apresentaram metilas isoladas, apresentando uma grande quantidade de metilas 1,4, metilas 1,5 e metilas 1,6 e cadeias longas. A presença de ramificações foi devido ao mecanismo denominado chain-walking. Os valores de ramificações nos PE foram maiores que 105 e menores que 277 ramificações/1000C. O aumento do número de ramificações foi devido ao aumento na temperatura de polimerização e uma diminuição da pressão de eteno. Os PE obtidos com o sistema (1)/MAO apresentaram peso molecular (Mw) elevado entre 44.000 e 105.000 Daltons e valores de polidispersão de 2,0 a 4,0, dependendo das condições reacionais. O peso molecular dos polímeros diminuiu com o aumento da temperatura de polimerização. / The combination of 1,4-bis(2,6-diisopropylphenyl)-acenaphthenediiminedichloronickel( II) (1) and methylaluminoxane (MAO) was highly active in ethylene polymerization under high pressures and temperatures. Herein we investigated the effects of ethylene pressure, reaction temperature, reaction time and amount of catalyst on polymer properties and reaction performance. The polyethylenes obtained with 1/MAO are highly branched. The branches goes from methyl to hexyl or even longer, and this without comonomer addition. These polyethylenes obtained do not shows isolated methyl groups, but shows 1,4-methyl, 1,5 and 1,6 methyl patterns. The branching was due to the so-called chain-walking mechanism. The branch content, which is in the range 105 to 277 branches/1000 C, increased with the temperature rising or the ethylene concentration decrease. The polyethylenes produced with these system have molecular weight between 44.000 and 105.000 Daltons and polydispersions from 2,0 to 4,0 depending on the reactions conditions. The polymer molecular weight tended to decrease with increasing polymerization temperature.

O complexo 1,4-bis(2,6-diisopropilfenil)-acenaftenodiimina-dicloroníquel(II) (1), em combinação com metilaluminoxano (MAO) foi utilizado para polimerizar eteno utilizando altas pressões e temperaturas. Foram investigados os efeitos da pressão de eteno, da temperatura, do tempo de reação e da quantidade de catalisador bem como, as propriedades dos polietilenos sintetizados. Os polietilenos obtidos com o sistema (1)/MAO foram altamente ramificados. As ramificações variaram de metil até hexil ou até mais longas, sem adição de comonômero. Os polietilenos não apresentaram metilas isoladas, apresentando uma grande quantidade de metilas 1,4, metilas 1,5 e metilas 1,6 e cadeias longas. A presença de ramificações foi devido ao mecanismo denominado chain-walking. Os valores de ramificações nos PE foram maiores que 105 e menores que 277 ramificações/1000C. O aumento do número de ramificações foi devido ao aumento na temperatura de polimerização e uma diminuição da pressão de eteno. Os PE obtidos com o sistema (1)/MAO apresentaram peso molecular (Mw) elevado entre 44.000 e 105.000 Daltons e valores de polidispersão de 2,0 a 4,0, dependendo das condições reacionais. O peso molecular dos polímeros diminuiu com o aumento da temperatura de polimerização. / The combination of 1,4-bis(2,6-diisopropylphenyl)-acenaphthenediiminedichloronickel( II) (1) and methylaluminoxane (MAO) was highly active in ethylene polymerization under high pressures and temperatures. Herein we investigated the effects of ethylene pressure, reaction temperature, reaction time and amount of catalyst on polymer properties and reaction performance. The polyethylenes obtained with 1/MAO are highly branched. The branches goes from methyl to hexyl or even longer, and this without comonomer addition. These polyethylenes obtained do not shows isolated methyl groups, but shows 1,4-methyl, 1,5 and 1,6 methyl patterns. The branching was due to the so-called chain-walking mechanism. The branch content, which is in the range 105 to 277 branches/1000 C, increased with the temperature rising or the ethylene concentration decrease. The polyethylenes produced with these system have molecular weight between 44.000 and 105.000 Daltons and polydispersions from 2,0 to 4,0 depending on the reactions conditions. The polymer molecular weight tended to decrease with increasing polymerization temperature.

No description available.

No description available.

No description available.

No description available.