Dimethylphenylphosphine complexes

The dimethylphenylphosphine complex frans- IrCl(CO)[P(CH3)2C6Hs]2 is. very useful in the study of the oxidative addition reaction. In addition to its high reactivity, the H nmr spectra of adducts of the complex are a convenient tool for obtaining stereochemical information about the addition of small molecules to square planar complexes.1... 

Where X is phenyl, the result of irradiation (sunlight, mercury lamp) is the formation of Ru(NO)X3(PPh3)(OPPh3) (X = Cl, Br) in the case of the diethyl-phenylphosphine complex, irradiation causes isomerization to the cis,mer-isomer. The frans,mer-isomer is the usual synthetic product, but in the case of dimethylphenylphosphine the/ac-isomer was obtained using short reaction times it isomerized to the usual mer,trans-isomer on heating [123],... 

Other halides can be introduced by metathesis. Figure 2.55 summarizes some of the complexes isolable with dimethylphenylphosphine, similar in general to the corresponding iridium complexes (section 2.13.3), including the photochemical isomerization of the mer-isomer. 

Figure 2.91 Structural data for iridium(III) complexes of dimethylphenylphosphine.

Two papers have appeared on the reactions of halogenophosphines with tervalent phosphorus compounds. In a detailed study of the reactions at 20 °C of a range of tertiary phosphines with phosphorus trichloride, dichlorophenylphosphine, and chlorodiphenylphosphine, it has been shown that, in general, 1 1 adducts are formed, provided that the tertiary phosphine is a good nucleophile. With diphenylchlorophosphine, for example, an adduct (18) is formed with dimethylphenylphosphine, but not with diphenylmethylphosphine, although the relative importance of steric and electronic factors remains to be established. The related reactions of phosphorus trichloride and of dichlorophenylphosphine are much more complex, and the initial crystalline products are not amenable to analysis. The reactions at 280 °C of a similar system have been shown to lead to halogen exchange, e.g. the conversion of (19) to (20). 

TaCl593 reacted with metallic sodium in neat trimethylphosphine to give the phosphinocarbene tantalum complexes 100 and 101, respectively. These reactions are the first examples of double activation of coordinated trimethylphosphine via oxidative cleavage of a substituent methyl C-H bond. A similar process was also observed in the reduction of tantalum pentabrom-ide with magnesium turnings in the presence of dimethylphenylphosphine.94... 

When the initial vinylcarbene complex is substituted with a second me-thoxycarbonyl group (complex 169), a different reactivity pattern is observed. Addition of methyldiphenylphosphine or dimethylphenylphosphine to 169 results in formation of the expected vinylketene complex 170. However, the analogous reaction with triphenylphosphine yielded a complex mixture at room temperature, and upon heating the simple ligand-substituted product 171 is formed. When 169 is reacted with carbon monoxide, the pyrone complex 172 is formed. Finally, reaction of the vinylketene... 

Steric effects appear to be very important in causing such ring closures if the complex used has dimethylphenylphosphine in place of di-/-butylphenylphosphine as the ligand, then a reaction such as Eq. (1) does not occur. 

The procedure reported here involves a one-pot reaction of the inexpensive reagent K[FeH(CO)4], which is readily available from Fe(CO)s, with a stoichiometric quantity of a phosphane in a protic medium. It affords the complexes Fe(CO)2(PR3)3 or Fe(CO)2[P(OR)3]3 in fair to high yields using tributylphosphine, dimethylphenylphosphine, and trimethyl, triethyl, and... 

Cationic methylplatinum(II)-nitrile complexes of the type m is-PtMeL2(NCR)+X have been isolated by the reaction of //vms-PtMeClL2, where L = dimethylphenylphosphine or trimethyl-arsine, with an aryl nitrile and AgX, where X = BF4, PF. Use of pentafluorobenzonitrile and 2,3,5,6-tetrafluorotetraphthalonitrile in alcohol has led to the synthesis of a series of imino ether complexes. A mechanism for imino ether formation, involving nucleophilic attack by an alcohol at a coordinated nitrile, is suggested and the course of the reaction is shown to be dependent not only on the alcohol but also on the size of the anion used.110... 

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