Trifluoromethyl-platinum complexes

Bis(trifluoromethyl)platinum complexes may conveniently be prepared by the reaction of dimethyl(cyclo-octa-l,5-diene)platinum with trifluoro-iodomethane in methylene chloride, followed by displacement of the cydo-octadiene with the required ligand L (L = AsMcs, PMeaPh, pyridine, RNC, etc.) Oxidative addition of iodine thence gives the platinum(iv) compounds ... 

Platinum complexes having heteroatoms in the alkyl ligands have been reported. Bond parameters for chloro (chloromethyl)platinum complexes 57 and 58 have been compared with the Pd complexes having similar coordination structures,and chloro(trifluoromethyl)platinum complexes with chelating ligands 59 and 60 have been prepared. ... 

Many of the recent efforts in this area of chemistry have been designed to explore the chemistry of the trifluoromethyl species prepared by these reactions. Among the more interesting results have been the construction of carbene and tetramethylcyclobutadiene ligands affixed to trifluoromethyl platinum cations (78), the synthesis of difluoro-carbene complexes like (Cp)Mo(CO)3CF2+ (79), the formation of (CF3)2CS from CF3Re(CO)5 (38), and the insertion reaction of S02 into CF3-metal bonds (80). 

A ruthenium complex, Ru(CO)2Cl2L, has been reported with ortfto-phenylenebis-(methylphenylarsine) (L) and there is a square-planar platinum complex (As—Pt 2.396 A) with the fully phenylated diarsine in which the metal atom also carries two p-(trifluoromethyl)phenyl groups . ... 

The bis(trifluoromethyl)platinum(IV) complex [PtIMe(CF3)2(py)2)] loses iodomethane slowly in acetone solution, in a process accelerated by photolysis or by addition of a nucleophile . The CF3 groups are not eliminated. The tetramethylplatinum(IV) species c s-[PtMe4(CNR)2] (R = Me, CsH3Me2-2,6) decompose by a first-order process to generate ethane and cis-[PtMe2(CNR)2] . 

Several trifluoromethylpyrazoles, for instance 3(5)-trifluoromethyl-5(3)-methylpyrazole (44) were used to prepare platinum complexes and the x-ray structure of the resulting complex reported <83 C774>. The ligand tris[3-trifluoromethyl-5-methyl(pyrazol-l-yl)]borate (82) yields a hydridovinyl iridium complex more stable than its j/ -ethylene isomer <89JA5480>. The x-ray structure of the related platinum complex (83) has been described <831C774>. 

The G-H bond activation of 4,4 -bis(trifluoromethyl)biphenyl by a Pt(0) complex of di(/-butyl)phosphinomethane at 40 °G forms the hydrido(aryl)platinum complex 388 (Scheme 52). " Heating 388 at 85 °G produces the complex with a biphenylene ligand 390 accompanied by loss of hydrogen. The results indicate that intermediate 389 is formed via reductive elimination of biaryl and its reoxidative addition,... 

The further reaction of these platinum complexes with an excess of acid to afford alkenes has received much less attention. If the alkyne bears the strongly electron-withdrawing trifluoromethyl group, the intermediate vinyl species is resistant to further electrophilic cleavage (Kemmitt et al., 1973). The diphenylacetylene complex, on the other hand, reacted with excess HCl to product trans-stilbene in almost quantitative yield (Tripathy and Round-hill, 1970). The corresponding 2-butyne complex gave a 1 4 mixture (the thermodynamic ratio) of cis and trans butenes under similar conditions. It is... 

To date, the only trifluoromethyl migrations that have been observed in compounds of the elements that are located in the third row of the transition metals occur in the two Ir(I) complexes which, as noted in Table I, retain the CO linkage after alkyl migration, in CF3CORe(CO)5 (38), and in the platinum(II) species for which a temperature of 210°C was required to initiate the decarbonylation. While the conditions of the last reaction clearly indicate that CF3-Pt bonds are very stable, many if not most organometallic species cannot survive this type of treatment, and the application of the technique to the heavier transition metals is therefore expected to be quite limited. 

The other main group elements which form peroxo complexes are d6 and d8 systems in group VIII including iridium, palladium and platinum. The ji-peroxo complexes do not generally catalyse the epoxidation of olefins with hydrogen peroxide,95,96 but it has been found that trifluoromethyl-substituted Pd(II) and Pt(II) hydroperoxides will perform such a transformation.97... 

Vhf of 1-8 Hz between the 3-CF3 fluorines and the hydrogens of the platinum-bound methyl groups has been observed by Fekl et al in the spectrum of the novel platinum(IV) complex, Tp(CF3)2PtMe3, where Tp(CF3)2 denotes hydridotris(3,5-bis(trifluoromethyl)pyrazolyl)borate. This is the first example of a formal Vf h(-c) coupling in complexes involving hydridotris(pyr-azolyl)borate ligands... 

Letuscitesomeothercharacteristicexamples.Thus,basedon5-(6-methylpyridin-2-yl)-3-trifluoromethyl-l,2,4-triazole ligand platinum(II) complexes 202 were synthesized with spatially encumbered chelates, and their photophysical properties were also studied [182]. Compound 202 was found to be weakly emissive in both... 

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