Chromium complexes tertiary phosphines

Although trialkyl- and triarylbismuthines are much weaker donors than the corresponding phosphoms, arsenic, and antimony compounds, they have nevertheless been employed to a considerable extent as ligands in transition metal complexes. The metals coordinated to the bismuth in these complexes include chromium (72—77), cobalt (78,79), iridium (80), iron (77,81,82), manganese (83,84), molybdenum (72,75—77,85—89), nickel (75,79,90,91), niobium (92), rhodium (93,94), silver (95—97), tungsten (72,75—77,87,89), uranium (98), and vanadium (99). The coordination compounds formed from tertiary bismuthines are less stable than those formed from tertiary phosphines, arsines, or stibines. 

The reaction is catalyzed by a group VIII metal species, particularly that of rhodium or palladium. The initial metal species may be any variety of complexes (e.g., PdCl2 Pd acetate, etc.). A source of halide is necessary iodide is especially effective. The most convenient source is methyl iodide, since it is likely a reaction intermediate. In addition, an organic promoter must be included for catalytic activity. These promoters are generally tertiary phosphines or amines. Also, chromium complexes were found to have an important promotional effect. 

Table 8 Tertiary Phosphine and Arsine Complexes of Chromium(0) Including Mixed...

Chromium(I) complexes, 702 alkyl isocyanides, 704-709 aryl isocyanides, 704-709 2,2 -bipyridyl, 709 electrochemistry, 713 electronic spectra, 712 ESR spectra, 712 IR spectra, 712 magnetic properties, 710 synthesis, 709 cyanides, 703 fluorophosphine, 716 isocyanides crystallography, 708 electrochemistry, 709 spectroscopy, 708 synthesis, 707 1,10-phenanthroline, 709 electrochemistry, 713 electronic spectra, 712 ESR spectra, 712 IR spectra, 712 magnetic properties, 710 synthesis, 709 tertiary phosphines dinitrogen, 713 tris(bipyridyl)... 

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