219497-90-2Relevant academic research and scientific papers
Synthesis and structure of [Pt3(μ-dppm)2(μ-PPh2)L 2](O3SCF3) (dppm = bis(diphenylphosphino)methane; L = CO, t-BuNC)
Wachtler, Helmuth,Schuh, Walter,Ongania, Karl-Hans,Wurst, Klaus,Peringer, Paul
, p. 5640 - 5646 (1998)
Treatment of [Pt2(μ-dppm)2Cl2] with 2 mequiv of AgO3SCF3 and bicyclo[2.2.1]hept-2-ene, respectively, in MeOH/CH2Cl2 results in a P-C cleavage of one dppm ligand to give [Pt2-(μ-dppm)(μ-PPh2)(η 2-bicyclo[2.2.1]hept-2-ene)2](O3SCF 3) (1a) and the methoxyphosphonium salt [PMePh2(OMe)](O3SCF3). Treatment of 1a with CO (1 atm) or 2 mequiv of t-BuNC gives [Pt2(μ-dppm)(μ-PPh2)L2](O 3SCF3) where L = CO (1b) or t-BuNC (1c). The reaction of 1b or le with 1 mequiv of dppm and [Pt(η2-bicyclo[2.2.1]hept-2-ene)3], respectively, gives [Pt3(η-dppm)2(μ-PPh2)L 2](O3SCF3) where L = CO (2a) or t-BuNC (2b). The new compounds were characterized by multinuclear NMR, FAB-MS, IR, and chemical analysis, 1a, 2a, and 2b additionally by single-crystal X-ray diffraction. In la, the orientation of the C=C double bonds is nearly in plane with the other ligands coordinated to the Pt atoms. The molecular structures of 2a and 2b show Pt3 triangles whose edges are spanned by two dppm ligands and one PPh2 ligand. There are bonds between the platinum atoms bridged by the dppm ligands (2.6456(8) and 2.6733(6) A? for 2a and 2.6463(11) and 2.6534(12) A? for 2b) while the separations of the Pt atoms bridged by the PPh2 ligand are very long (2a, 3.5949(6) A?; 2b, 3.470(1) A?) and are clearly considered as nonbonding. The CO or t-BuNC ligands are coordinated terminally to the Pt atoms bridged by the PPh2 ligand. The P atom of the phosphido group exhibits a short intramolecular contact to the third Pt atom of 2.954(3) A? (2a) or 2.933(5) A? (2b), which is significantly below the sum of the van der Waals radii of phosphorus and platinum.
