195Pt, 119Sn AND 31P NMR STUDIES OF ALKYL, ARYL AND ACYL TRICHLOROSTANNATE COMPLEXES OF PLATINUM(II). THE CRYSTAL STRUCTURE OF trans-

Article abstract of DOI:10.1016/0022-328X(85)80276-X

195Pt, 119Sn and 31P NMR characteristics of the complexes tans-).The values of ¹J(195Pt, 119Sn) vary from 2376 to 11895 Hz with the COPh ligand having the smallest and the C6H5 ligand the largest value, making a total range for this coupling constant, when the dimer syn-trans-2 is includeed, of ca. 33000 Hz.In the meta- and para-substituted phenyl complexes ¹J(195Pt, 119Sn) (a) is greater for electron withdrawing substituents, (b) varies more for the meta-substituted derivatives (5634 to 7906 Hz) than for the para analogues (6088 to 7644 Hz) and (c) has the lowest values when the group is the meta- or para-substituent.The direction of the change in ¹J(195Pt, 119Sn) is opposite to that found for ¹J(195Pt, 31P).For the aryl complexes linear correlations are observed between δ(119Sn),¹J(195Pt, 119Sn), ¹J(195Pt, 31P), ²J(119Sn, 31P) and the Hamett substituent consatnt ?ⁿ. δ(119Sn) and ¹J(195Pt,119Sn) are related linearly to ν(Pt-H) in the complexes trans-; δ(119Sn) and δ(1H) (hydride) are also linearly related.Based on ¹J(195Pt,119Sn), the acyl ligand is suggested to have a very large NMR trans influence.The differences in the NMR parameters for (1a-e) are rationalized in terms of differing ?- and ?-bonding abilities of the carbon ligands.The structure of 1c has been determined by crystallographic methods.The complex has a slightly distorted square planar geomety with trans-PEt3 ligands.Relevant bond lengths (Angstroem) and bond angles (deg) are: Pt-Sn, 2.634(1), Pt-P, 2.324(4) and 2,329(4), Pt-C, 2.05(1); P-Pt-P, 170.7(6), Sn-Pt-C, 173.0(3), Sn-Pt-P, 92.1(19, 91.7(1), P-Pt-C, 88.8(4) and 88.3(4).The Pt-Sn bond separation is the longest yet observed for square-planar platinum trichlorostannate complexes, and would be consistent with a large crystallographic trans influence of the benzoyl ligand.The Pt-Sn bond separation is shown to correlate with ¹J(195Pt, 119Sn).