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Styrene SULPHOS

The SULPHOS-containing rhodium and ruthenium complexes retained their catalytic activity in heteroarene hydrogenation when supported on styrene-divinylbenzene polymer [180] or on silica [181], and showed even higher activity than in homogeneous solution. This effect is attributed to the diminished possibility of dimerization of the active catalytic species to an inactive dimer on the surface of the support relative to the solution phase. The strong hydrogen bonds between the surface OH-groups on silica and the -SO3 substituent in 31 withheld the catalyst in the solid phase despite the rather drastic conditions (100 °C, 30 bar H2). [Pg.94]

Bianchini et al. [15] reported a sulfonated ligand for use in hydrogenation reactions. They synthesized the complex [Rh(sulphos)(cod)j (where sulphos is structure 3), which was tested in the biphasic hydrogenation of styrene. Styrene was dissolved in a 1 1 (v/v) mixture of methanol and n-heptane in the presence of... [Pg.314]

Rh(sulphos)(cod)] (1 500 catalyst/substrate ratio). The hydrogen pressure was 3 MPa, and the temperature was 65 °C. After 3 h a conversion of more than 90% was obtained and complete disappearance of styrene occurred after a further 2 h of reaction. After cooling the reaction mixture to room temperature, separation of the two phases did not give complete organic product separation, whereas the rhodium catalyst remained in the alcohol phase. Simple addition of water resulted in complete elimination of ethylbenzene (and residual styrene) from the alcohol phase. Remarkable, the catalytic activity of [Rh(sulphos(cod)] in the biphasic system is the same as in pure methanol, indicating that at the reaction temperature a homogeneous phase is formed. [Pg.315]


See other pages where Styrene SULPHOS is mentioned: [Pg.360]    [Pg.360]    [Pg.87]    [Pg.281]    [Pg.506]   
See also in sourсe #XX -- [ Pg.77 , Pg.198 , Pg.314 ]




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