33677-20-2Relevant academic research and scientific papers
Synthesis and reactivity of new κ2-[P,N]Pt(II) complexes of diisopropylphosphino-substituted 2-dimethylaminoindene
Wile, Bradley M.,McDonald, Robert,Ferguson, Michael J.,Stradiotto, Mark
, p. 1959 - 1965 (2005)
Treatment of 1-PiPr2-2-NMe2-indene (la[H]) with either czs/trans-(SMe2)2PtCl2 or PtCl2 provided (κ22-P,N-2-NMe2-3-P iPr2-indene)PtCl2 (2) in 84% and 55% yield, respectively, while the reaction of 1a[H] with (η4-COD)PtClMe afforded (κ2-P,N-2-NMe2-3-PiPr 2-indene)PtClMe (3) in 91% yield. Whereas in the formation of 2 and 3 the ligand precursor 1a[H] undergoes a rearrangement to give a coordinated 2-NMe2-3-PiPr2-indene (1b[H]) ligand, 1a[H] reacted cleanly with 0.5 equiv of [(μ-SMe2)PtMe2] 2 to give (κ2-P,N-1a[H])PtMe2 (4a) in 97% yield. The isomerization of 4a to (κ2-P,N-1b[H])PtMe 2 (4b) in a THF/iPrOH mixture is rapid and allowed for the isolation of 4b in 99% yield. Heating of 4a in CH2Cl2 resulted in the quantitative formation of 3, while the thermolysis of 4a in toluene in the presence of SMe2 afforded 5, the apparent product of intramolecular C-H activation of an NMe group. The reactivity of 4a with a variety of other two-electron donors, as well as E-H-containing substrates (E = main group fragment), is reported. Although NMR spectroscopic evidence indicated the formation of an intermediate of the type (κ2-P,N-1[H]) Pt(SnPh3)(Me), as well as Ph6Sn2, in the reaction of 4a with 10 equiv of Ph3SnH, negligible conversion of Ph3SnH to Ph6Sn2 was obtained when employing 1 mol % 4a as a catalyst. Single-crystal X-ray diffraction data for 2 and 5 are reported.
Binding of specialty phosphines to metals: Synthesis, structure, and solution calorimetry of the phosphirane complex [PtMe2(iPrBABAR-Phos)2]
Laporte, Cecile,Frison, Gilles,Gruetzmacher, Hansjoerg,Hillier, Anna C.,Sommer, William,Nolan, Steven P.
, p. 2202 - 2208 (2008/10/08)
The complex [PtMe2(iPrBABAR-Phos)2] (3) was prepared in a clean and quantitative ligand substitution reaction from [PtMe2(cod)] (1; cod = η4-1,5-cyclooctadiene) and the phosphirane iPrBABAR-Phos (2). The structure of 3 was determined by X-ray diffraction. The Pt-P bonds (～2.26 A) lie in the shorter range of PtII-P bonds, although the 1J(195Pt31P) coupling (1840 Hz) is quite small. The enthalpy for this ligand substitution reaction was measured by solution calorimetry and found to be exothermic by 11.8 kcal/mol, a relatively low exothermicity for a reaction involving a tertiary phosphine in this Pt system. Calculations using density functional theory (DFT) on the B3LYP level were applied using the simplified model reaction [PtH2(cod)] + 2(H2N)PC2H4 → [PtH2{(H2N)PC2H4}2)] + cod, and these also gave a rather low substitution enthalpy (-17 kcal/mol). A charge decomposition analysis (CDA) was performed for Pt(II) and Pt(0) complexes with the simple P-amino phosphirane (H2N)PC2H4 and PH3 as ligands. Contrary to expectations, it is found that the phosphirane acts as a relatively good electron donor, while its electron-acceptor properties are not significantly different from those of other phosphines. The particularly low reaction enthalpy may thus be due to a low directionality of the donor orbitals toward the metal center.
