TRIFLUOROMETHYLTHIO AND TRIFLUOROVINYL COMPLEXES OF PLATINUM(II) - MEASUREMENT OF CIS-INFLUENCE AND TRANS-INFLUENCE BY P-31 AND F-19 NUCLEAR MAGNETIC-RESONANCE SPECTROSCOPY

19F and 31P NMR data are reported for four series of complexes: (i) trans- [PtX(SCF3)(PEt3)2], X C6H5, CH3, H, CF3, C2F3, CN, NO2, SCF3, N3, I, NCS, Br, Cl, and NO3. (ii) cis-[PtX(SCF3)(PEt3)2], X CH3, NO2, SCF3, N3, NCS, NCO, and Cl. (iii) trans-[PtX(C2F3)(PEt3)2], X CN, NO2, SCF3, N3 I, Br, Cl, and NO3. (iv) trans-[Pt(C2F3)(PEt3)2L][ClO4], L PEt3, P(OEt)3, P(OMe)3, P(OPh)3, PPh3, CO, and C5H5N. The results are used to establish scales of cis- and trans-influence for the X and L ligands and comparisons suggest that the cis-influence is much more sensitive to π-bonding, and possibly also to steric effects, than is the trans-influence. The π-bonding and steric effects are less evident when indirect coupling constants are used to measure the cis-influence and under these conditions rough inverse correlations with trans-influence may be obtained. © 1979.