Geometrical characteristics from experiment and theory of isostructural complexes involving palladium and platinum-methyl bonds

Synthesis, characterization, and crystal structure of cis‐[Pt(Me)2{PPh2(OMe)}2] and the conversion into cis‐[Pt(OH2)2{PPh2(OMe)}2][OTf]2

“…Only two crystal structures have been reported to date for platinum complexes having two PPh 2 (OMe) ligands; cis‐ [Pt(η 2 ‐S 2 CO){PPh 2 (OMe)} 2 ] 13 and trans‐ [Pt(CN) 2 {PPh 2 (OMe)} 2 ] 14. The Pt–P bond distances (2.2554(11) and 2.2604(12) Å) and Pt–C bond distances (2.123(5) and 2.110(5) Å) in 1 are similar to those of previously reported analogous complexes 8,15,16. Figure 2 shows a molecular representation of the dicationic complex 2 , in which the platinum atom is coordinated to the phosphorus atoms of the two PPh 2 (OMe) ligands in cis positions and the two OH 2 ligands, acquiring a square‐planer configuration.…”

“…In the 1 H NMR spectrum of 1 , an apparent triplet at δ 1.20 was observed with 6.0 Hz splitting, being reasonably assigned to the methyl groups on the Pt center. The observed coupling constant, 3 J (H–Pt) = 65.9 Hz, is in the range of those for cis‐ dimethylplatinum complexes having two tert ‐phosphorus ligands or a bidentate‐phosphine ligand (66–76 Hz) 7,8. The 31 P{ 1 H} NMR spectrum of 1 showed a signal at δ 116.71 flanked by 195 Pt satellites ( 1 J (P–Pt) = 2204 Hz).…”

Solution, Structural and Catalytic Studies of Neutral MCl2 (M = Pd, Pt) Complexes of the N/E Mixed‐Donor Ligands 2‐(RECH2)C5H4N(RE = MeS, PhS, MeSe)

“…Similar trends in bond distances in isomorphous structures of palladium and platinum complexes containing homoleptic and heteroleptic ligands have been observed, and theoretical calculations have been performed to explain the trend. [14][15][16][17][18][19] Results from theoretical calculations for the geometry optimisations of the complexes [MMe 3 {(H 2 C=N-NH) 3 CH}] + compared well with the X-ray studies of isostructural [MMe 3 {(pz) 3 -CH}] + (M = Pd, Pt), where the M-C bond distances are identical or slightly shorter for palladium and platinum while the Pd-N bonds are longer than the Pt-N bonds. [19] The explanation for this trend is attributed to the softer acidity of platinum compared with palladium.…”

The Activation of Dihydrogen

“…It had been observed experimentally that CH 4 loss from Pt(H)(CH 3 )(PPh 3 ) 2 is quite facile even at -25 8C [83], while the Pt(CH 3 ) 2 (PPh 3 ) 2 complex is stable against CH 3 CH 3 loss up to 237 8C [84]. Low and Goddard, utilizing electronic structure calculations, demonstrated that the observed reactivity (or lack thereof) was a result of the barrier to reductive elimination and not the thermodynamics of the reaction [85][86][87][88][89][90]. They argue that while the sp 3 hybridized orbital of CH 3 requires nearly complete scission of the M-C bond prior to C-C bond formation for Pt(CH 3 …”