Study of Bulky Phosphorus Diamide Ligands

Chart 6.8 Phosphorus diamide ligands studied by van Leeuwen et al. 

Immediately after addition of 1-octene, the strong absorption band indicative of aldehyde formation (1734 cm ) appeared in the IR spectrum, proving that the hy-droformylation reaction had started. The amount of 18b dropped considerably upon addition of 1-octene, but it did not disappear completely during the hydrofor-mylation reaction. Seven new absorptions appeared in the terminal carbonyl region indicating that complex 18b was converted (in part) to several new carbonyl-containing rhodium complexes. 

The rhodium hydride complex, 18b, was the only rhodium complex observed during the hydroformylation reaction at increased partial hydrogen pressure of 32 bar, as concluded from the absence of carbonyl signals in the IR difference spectra. The spectrum of the rhodium hydride resting state is taken as background at 

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Study of Bulky Phosphorus Diamide Ligands 2S7 Table 6.8 IR frequencies obtained in the stoichiometric reaction of 18b (L = 17b), 1-octene, CO... 

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