Synthesis and Structural Characterization of an Unusual Platinum π-Arene Complex: (η<sup>6</sup>-C<sub>6</sub>H<sub>3</sub>Me<sub>3</sub>)Pt[(C<sub>2</sub>F<sub>5</sub>)<sub>2</sub>PMe]Me<sup>+</sup>
作者:Bhusan Thapaliya、Suman Debnath、Navamoney Arulsamy、Dean M. Roddick
DOI:10.1021/acs.organomet.5b00410
日期:2015.8.24
Treatment of cis-(dfmp)(2)PtMe2 (dfmp = (C2F5)(2)PMe) with the mesitylenium acid (C6Me3H4)B+-(C6F5)(4)(-) in 1,2-difluorobenzene cleanly produces an unusually stable arene complex, [(eta(6)-C6Me3H3)Pt(dfmp)(CH3)](+) (B-(C6F5)(4))(-) (1). Facile arene exchange and competitive binding equilibria have been quantified for mesitylene relative to toluene (K = 0.0030(3)) and durene (K = 20(2)). Reaction of 1 with H-2 at 80 degrees C results in hydrogenolysis to form the arene hydride (eta(6)-C6Me3H3)Pt(dfmp)(H)(+) (2), while treatment of 1 with CO gives trans-(dfmp)(2)Pt(CO)Me+ as the major phosphine product. Addition of excess Me3P to 1 results in both arene and dfmp displacement to form (Me3P)(3)PtMe+center dot (eta(6)- C6Me3H3)Pt(dfmp)(CH3)(+) is a moderately active ethylene dimerization catalyst to form 2-butenes (similar to 7 TO h(-1), 20 degrees C).
Adduct Studies and Reactivity of <i>trans</i>-[(C<sub>2</sub>F<sub>5</sub>)<sub>2</sub>MeP]<sub>2</sub>Pt(Me)X (X = O<sub>2</sub>CCF<sub>3</sub>, OTF, OSO<sub>2</sub>F)
作者:Jeffrey L. Butikofer、Thomas G. Parson、Dean M. Roddick
DOI:10.1021/om060847p
日期:2006.12.1
The comparative reactivity properties of previously reported trans-(dfmp)(2)Pt(Me)X (dfmp = (C2F5)(2)-MeP; X = O2CCF3, OTf, OSO2F) with small molecules are presented. Anionic ligand displacement by CO depends upon X and the corresponding acid solvent. In trifluoroacetic acid, treatment of trans(dfmp)(2)Pt(Me)(O2CCF3) with CO results in loss of dfmp to form the mixed phosphine/carbonyl product (dfmp)(CO)Pt(Me)(O2CCF3). However, in triflic and fluorosulfonic acids trans-(dfmp)(2)Pt(Me)(X) compounds react with CO to form trans-(dfmp)(2)Pt(Me)(CO)(+)(X)(-). trans-(dfmp)(2)Pt(Me)(X) systems react with H-2 under both acidic and aprotic conditions to form trans-(dfmp)(2)Pt(H)(X); trans-(dfmp)(2)Pt(H)(OTf) has been crystallographically characterized. Treatment of trans-(dfmp)(2)Pt(H)(OTf) with CO or dfmp gives trans-(dfmp)(2)Pt(H)(CO)(+) or (dfmp)(3)Pt(H)(+), respectively. In contrast to trans-(dfmp)(2)Pt(Me)(OTf), which releases methane in HOTf, trans-(dfmp)(2)Pt(Me)(OSO2F) in FSO3H at 80 degrees C cleanly produces the reductive elimination product MeOSO2F. Carbonylation of trans-[(dfmp)(2)PtMe(CO)]X-+(-) under 1000 psi CO in turn cleanly produces MeC(O)X at ambient temperatures. The mechanism of reductive elimination from these Pt(II) precursors is discussed.
Organometallics in Superacidic Media: Characterization of Remarkably Stable Platinum–Methyl Bonds in HF/SbF<sub>5</sub> Solution
作者:Thomas G. Parson、Jeffrey L. Butikofer、James F. Houlis、Dean M. Roddick
DOI:10.1021/acs.organomet.6b00624
日期:2017.1.9
The protolytic stability of (dfepe)PtMe2 (dfepe = (C2F2)(2)PCH2CH2P(C2F5)(2)) and cis-(dfmp)(2)PtMe2 (dfmp = (C2F5)(2)PMe) and NMR characterization of their corresponding products in SbF5-HF superacid solvent mixtures are reported. Dissolution of (dfepe)Pt(Me)(2) in 10 mol % of SbF5-HF at -60 degrees C resulted in the clean protonolysis of a single Pt-Me bond to form the cationic methyl complex (dfepe)Pt(Me)(+); further conversion of (dfepe)Pt(Me)(+) to (dfepe)Pt2+ occurred upon warming to -20 degrees C and followed pseudo-first-order kinetics (k = [1.4(2)] x 10(-2) min(-1)). In contrast, dissolution of the nonchelating analogue cis-(dfmp)(2)PtMe2 in 10 mol % of SbF5-HF at 20 degrees C evolved methane and cleanly produced the stable monomethyl complex trans-(dfmp)(2)Pt(Me)(+). trans-(dfmp)(2)Pt(Me)(+) is the most protolytically stable organometallic known: 33% conversion to the cis dicationic product cis-(dfmp)(2)Pt2+ requires 2 weeks in 10 mol % of SbF5-HF at 20 degrees C, whereas >90% conversion was observed in 30 h in 50 mol % of SbF5-HF. Dissolution of cis-(dfinp)(2)Pt(CD3)(2) cleanly generated trans(dfmp)(2)Pt(CD3)(+), which subsequently underwent complete proton incorporation to produce trans-(dfmp)(2)Pt(CH3)(+) within 1 h at 25 degrees C. This labeling study supports the reversible formation of the methane complex intermediate trans-(dfmp)(2)Pt(CH4)(2+) under these conditions. Treatment of trans-(dfmp)(2)Pt(Me)(+) in 10 mol % of SbF5-HF at -100 degrees C with 200 psi of H-2 resulted in the clean formation of the dihydrogen complex trans-(dfmp)(2)Pt(Me)(eta(2)-H-2)(+), which upon warming to -20 degrees C underwent methane loss and generated the hydride product trans-(dfmp)(2)Pt(H)(+). The dihydrogen complex trans-(dfmp)(2)Pt(H)(eta(2)-H-2)(+) has not been directly observed but has been implicated in exchange bradening behavior observed for trans-(dfmp)(2)Pt(H) under H-2. Treatment of trans-(dfmp)(2)Pt(CD3)(+) in 10 mol % of SbF5-HF at -40 degrees C with 200 psi of H-2 cleanly produced trans(dfmp)(2)Pt(CD3)(eta(2)-H-2)(+) No significant H/D exchange into the Pt-CD3 group prior to trans-(dfmp)(2)Pt(H)(+) formation was observed.