Trifluoromethylplatinum complexes and the nature of the platinum-trifluoromethyl bond

Abstract

Complexes of the types trans-Pt(CF3)Q2L+ and Zro»j-Pt(CF3)ZQ2 have been prepared, where Q = P(CH3)2(C6H5), L is a neutral ligand, and Z is an anionic ligand. 2/pt-CF3 for these complexes varies linearly with 2/pt-ch3 for the corresponding methylplatinum complexes, except where L requires synergicbonding. The results suggest that the Pt-CF3 bond does not depend very much on back-bonding for its stability. The trans influence of the trifiuoromethyl group is discussed, and some reactions of the trifluoromethylplatinum complexes are compared with those of corresponding methylplatinum compounds.

Gold(I) and Gold(III) Trifluoromethyl Derivatives

“…The process depicted in Equation (3) is quite convenient, because it allows compounds 3 – 5 to be prepared under mild conditions in high yields and in a stereoselective way. Both the stereoselectivity of the process and the stereochemistry of the final products [PPh 4 ][ trans ‐Au III (CF 3 ) 2 X 2 ] ( 3 – 5 ) are remarkable considering the high trans influence of the CF 3 group 31. In fact, the non‐fluorinated homologous species [AsPh 4 ][Au III (CH 3 ) 2 X 2 ] have exclusively the cis structure…”

“…(3-5) are remarkable considering the high trans influence of the CF 3 group. [31] In fact, the non-fluorinated homologous species […”

Highly Trifluoromethylated Platinum Compounds

“…We will try to rationalize the observed differences in terms of fundamental parameters in use in coordination chemistry; the careful work of H. C. Clark is taken as a basis on the subject. [50] The data of our halo-compounds F) values observed for the equatorial than for the axial CF 3 groups can be attributed to the significantly shorter Pt À C bond lengths found for the latter within the same chemical species.…”

“…[44] The long PtÀCO bond length found in 6' is, in our opinion, the most salient feature of this molecular structure and is in keeping with the electrophilic character suggested by the high n(CO) value (which appears shifted to 2200 cm À1 in solid samples of 6'; see Table 2) as well as with the known high trans influence exerted by the CF 3 ligand. [50] To the best of our knowledge, this is the longest Pt À CO bond length observed for any terminal carbonyl derivative of Pt reported so far [52,53] -including the highly electrophilic…”

“…This difference is to be attributed to the higher trans influence of the CF 3 group with respect to the Cl ligand. [50] We have at our disposal a rather homogeneous set of compounds with formula [PtA C H T U N G T R E N N U N G (CF 3 ) 5 …”