1H, 13C and 195Pt n.m.r. spectra of Trimethylplatinum(IV) Tetramers [PtMe3Z]4: effects of Pt-Z-Pt and long-range Pt-Z-Pt-C couplings

Abstract

1H, 13C and 195Pt n.m.r. spectra have been obtained for [PtMe3(μ3-Z)]4 (Z = Cl, Br, I, OH, N3, SMe, SPh, and SCF3). The compounds with Z = SPh and SCF3 have not previously been prepared. In those tetramers which contain more than one 195Pt nucleus, and where 195Pt-Z-195Pt coupling is significant, 1H and 13C spectra cannot be interpreted as first order. Values of 2JPt-Z-Pt have been calculated from 13C spectra where Z = SMe, SPh, OH, and N3, and upper limits estimated for a number of other Z. When Z = SMe and OH, long-range 195Pt-Z-Pt-13C coupling is resolved. 2J(195Pt-S-13C) when Z = SMe and SCF3, and 3J(195Pt-S-C-19F) when Z = SCF3, are unexpectedly small. The 195Pt resonance frequency decreases in the order Z = OH > SPh > SMe > N3 ≈ Cl > Br ≈ SCF3 > I. To assist in analysing the spectra transition frequencies and intensities have been calculated for the AA'2X spectrum (available as an accessory publication).

Chemical Shift Anisotropy of Organometallic Carbon

“…We therefore report the isotropic shifts, and where appropriate J Pt - C for all compounds, in Table . In general these do not differ significantly from literature values obtained in solution, where those have been reported. ,,,,− …”

“…In general these do not differ significantly from literature values obtained in solution, where those have been reported. 16,17,19,24,[30][31][32][33] It will be noted that in many cases the crystallographic symmetry is lower than the symmetry of the free molecule, and lines are split. For example, in the spectrum of cis-PtMe 2 (dmso) 2 (Figure 1), there are two Pt-Me lines and four S-Me lines, indicating that the asymmetric unit contains not less than one full molecule.…”

Novel Platinum(IV)−Carbohydrate Complexes: Metal Ion Coordination Behavior of Monosaccharides in Organic Solvents

“…This broadening might be caused by unresolved small 2 J PtOC couplings. In related trimethylplatinum complexes, these couplings have not been observed, but 2 J PtSC values have been shown to be small (1−4 Hz) …”

Synthesis and Characterization of {Re(CO)3}4-n{PtMe3}n(OH)4, (n = 1−3). A Set of Heterobimetallic Hydroxy Cubane Complexes

“… a In acetone or acetone- d 6 . b Referenced to an external solution of NaPtCl 6 in D 2 O. c Literature NMR values: 1 H NMR (C 6 H 6 ) δ 0.85 ( 2 J Pt - H = 78.8 Hz), −1.52 ( 2 J Pt - H = 11.3 Hz); 1 H NMR (C 6 D 6 ) δ 0.84 ( 2 J Pt - H = 78.8 Hz), −1.50 ( 2 J Pt - H = 11.4 Hz); 195 Pt NMR (C 6 D 6 ) −1511 ppm, (acetone- d 6 ) −1453 ppm; 1 H NMR (CDCl 3 ) δ 0.90 ( 2 J Pt - H = 78.3 Hz), −0.53 …”