Halogeno-carbonyl and -phosphine complexes

Stephenson and E. Switkes, Inorg. Nuclear Chem. Letters, 1971, 7, 805. 

The new five-co-ordinate complex [RuCl2(CO)(PCy3)2] (PCy3 = tricyclohexyl-phosphine) has been prepared (equation 4).17 Its i.r. spectrum suggested the structure 

Halogeno-carbonyl and -phosphine Complexes. In an attempt to measure the charge distribution in complexes, the dipole moments of a number of complexes have been collected and group moments assigned.  

Halogeno-carbonyl and -phosphine complexes. I.r. spectral studies at elevated CO pressures have indicated that carbon monoxide, like other Lewis bases, is capable of bridge splitting in rhodium dicarbonyl halides, as in reaction (15).  

They also report similar bridge-splitting reactions with Lewis bases, including P(OPh)3, to give mixed RhX(CO)L L. The latter complexes were assigned a trans geometry on the basis of their v(CO) and v(RhX) frequencies. 

The terdentate ligand PhP(CH2CH2CH2PPh2)2 readily forms complexes of the type RhLX (X = Cl, Br, or I), which have the advantage of being dis-sociatively stable in non-aqueous solvents. Studies of their activation of small molecules A show that they readily form five-co-ordinate adducts RhLCl,A (A = BF3, CO, SO2, O2). On the other hand, cationic derivatives can be obtained employing either reaction (16) or reaction (17). 

An alternative low-pressure route to the known complex [RhCl(PF3)2]2 has been reported, via the sealed tube reaction of excess PF3 on 

Uguagliati, G. Deganello, L. Busetto, and U. Belluco, Inorg. Chem.. 1969, 8, 1625. 

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Rhodium(i).—Group VII Donors. Halogeno-carbonyl and -phosphine complexes. Convenient atmospheric pressure syntheses have been reported for the complexes [RhCI(PF3)2]2 and [Rh(acac)2(PF3)2], by replacing olefins from suitable substrate complexes, e.g. 

Halogeno-carbonyl and -phosphine complexes. An interesting paper reports that for the equilibrium [Ir(CO)2(Cl4] -I in non-aqueous solvents, the iridium(m) anion exhibits novel ambivalent acceptor properties, i.e. it displays soft acceptor halide preference at two halide positions, but hard behaviour at the other halide positions. ... 

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