Preparation and X-ray Crystal and Molecular Structure of cis-[(dppp)Pd(H2O)(OSO2CF3)]+(OSO2CF3)- and cis-[(dppp)Pd(H2O)2]2+(OSO2CF3)-2 Coordinated Water-Triflate Hydrogen Bonds

Stang, Peter J.; Cao, Danh H.; Poulter, Gregory T.; Arif, Atta M.

doi:10.1021/om00003a012

Cited by 75 publications

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“…The Pd-P distances (2.217(1) and 2.233(1) Å ) fit within the reported experimental range and are similar to those found in [Pd(OTf)(H 2 O)(dppp)] (OTf) [42]; the Pd-O distances (2.097(2) and 2.093(2) Å ) are very short and close to the values found in [Pd(OS(Me)O)(dppp)] 2 (BAr 4 ) 2 [41] (2.078(5) and 2.088(5) Å ). However, in the present complex the chelate ligand is dianionic and the formal oxidation state of sulfur is +6, while compound [41] is a dinuclear complex in which a monoanionic ligand bridges two Pd units and the formal oxidation state of sulfur is +2.…”

Section: Characterization and X-ray Structure Of Complex (I)supporting

confidence: 85%

“…With respect to bond angles, the P(1)-Pd-P(2) angle (90.78(3)°) is similar to those reported in [Pd(OTf)-(H 2 O)(dppp)](OTf) [42] and [Pd(OTs)(H 2 O)(dppp)](OTs) [32], and is also close to the average of 92.5°found in about thirty analogous Pd compounds [40]; on the other hand, the O (1) Fig. 1.…”

Section: Characterization and X-ray Structure Of Complex (I)supporting

confidence: 81%

“…To the best of our knowledge, this is the first example of a Pd(II) complex with a chelating sulfate dianion. A search in the Cambridge Crystallographic Database (CCD) [40] for square planar Pd(II) complexes showing the (P \ P)O 2 donor set and at least one oxygen bound to a sulfur atom (P \ P = bidentate neutral phosphorous ligand) returned five entries [11,41,42]. The main geometrical parameters for the reported structures are listed in Table 3.…”

Section: Characterization and X-ray Structure Of Complex (I)mentioning

confidence: 99%

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Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Cavinato

Vavasori

Toniolo

et al. 2005

Inorganica Chimica Acta

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The title complex has been synthesized by first reacting dppp with Pd(AcO) 2 in acetone and then with NaHSO 4 in water. It has been characterized by IR, NMR and X-ray diffraction studies. The 31 P NMR spectrum in DMSO shows a singlet at 16.62 ppm indicating that the two P atoms are equivalent and that the sulfate anion is weakly coordinating. The X-ray structure shows that the Pd atom is surrounded in an almost regular square planar environment by the two P atoms and by two O atoms of the sulfate anion and that the neutral complex is accompanied by a water molecule of crystallization. The Pd-P distances (2.217(1) and 2.233(1)) and the P-Pd-P angle (90.78(3)°) are close to those found in other complexes where the chelating diphosphine is the same. Also the Pd-O distances and the O-Pd-O bond angle are comparable to those of other relevant chelating ligands.In MeOH, the title complex, in combination with H 2 SO 4 , catalyses the CO-ethene copolymerization. The productivity reaches a maximum upon increasing the H 2 SO 4 /Pd ratio up to ca. 470 (7650 g of polyketone/g Pd h at 90°C and 45 atm, CO/ethene 1/1). The viscosity of the polyketone passes through a maximum of 0.95 dL/g in m-cresol when the above ratio is ca. 100. It has been proposed that acid promotes the copolymerization process by destabilizing the b-and c-chelates intermediates involved in chain growing process, thus favoring the insertion of the monomers. At relatively high acid concentration the lowering of productivity and viscosity suggests that the sulfate anion competes with the monomers for the coordination to the metal center.In H 2 O-CH 3 COOH as a solvent the productivity strongly depends on the H 2 O/CH 3 COOH ratio, as it passes through a maximum of 12 000 g polymer/g Pd h in the presence of ca. 60% of H 2 O. The productivity is significantly lower than that found when the acetate and chloride analogues are used (27 000 g polyketone/g Pd AE h). Thus, it is likely that the sulfate anion assists significantly the copolymerization process even though the concentration of CH 3 COOH/CH 3 COO À is much preponderant.

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Section: Characterization and X-ray Structure Of Complex (I)supporting

confidence: 85%

Section: Characterization and X-ray Structure Of Complex (I)supporting

confidence: 81%

Section: Characterization and X-ray Structure Of Complex (I)mentioning

confidence: 99%

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Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Cavinato

Vavasori

Toniolo

et al. 2005

Inorganica Chimica Acta

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“…Interestingly, despite the presence of two hydration water molecules and of two p-toluenesulfonato anions, a situation similar to that reported by Stang et al [25], no efficient intermolecular interactions are present in the complex. In fact, the closest intermolecular contacts between the complexed water molecules and the oxygen atoms of the sulfonato groups are greater than 2.6 A; the distances between the OW1 and OW2 atoms of the hydration water molecules and the oxygen atoms of the sulfonato groups are even larger.…”

Section: X-ray Structure Analysis Of the Complexes Ia And Iia á 2ch 2supporting

confidence: 81%

“…The IR spectrum of both Ia and IIa shows two broad absorptions at 3508, 3445 cm À1 and 3534, 3489 cm À1 , respectively, assigned to m as (O-H) and m s (O-H) of the water molecules [13,[22][23][24][25] …”

Section: X-ray Data Collection Structure Solution and Refinementmentioning

confidence: 99%

Synthesis, characterization and catalytic activity in the carbonylation of ethene of cis-[Pd(H2O)2(PPh3)2]X2·nH2O (X=p-CH3C6H4SO3, n=2; X=CH3SO3, n=0). X-ray structure of cis-Pd(H2O)2(PPh3)2](p-CH3C6H4SO3)2·2H2O and of cis-[Pd(H2O)2(PPh3)2](CH3SO3)2·2CH2Cl2

Cavinato¹,

Vavasori²,

Toniolo³

et al. 2004

Inorganica Chimica Acta

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The complexes cis-[Pd(H 2 O) 2 (PPh 3 ) 2 ]X 2 AE nH 2 O (Ia: X ¼ p-CH 3 C 6 H 4 SO 3 , n ¼ 2; IIa: X ¼ CH 3 SO 3 , n ¼ 0) have been synthesized by reacting Pd(OAc) 2 , PPh 3 and HX in acetone in the presence of H 2 O. They have been characterized by IR, 1 H and 31 P NMR spectroscopy and TA analysis. By re-crystallization of these complexes, crystals of Ia and IIa AE 2CH 2 Cl 2 suitable for the X-ray analysis have been obtained. The solid-state investigation of Ia reveals that the two p-toluenesulfonato units act as counter anions of a dicationic complex, in which the metal atom is surrounded in a square planar environment realized by two water molecules and two PPh 3 moieties that are cis to each other. The X-ray investigation of IIa AE 2CH 2 Cl 2 shows that also in this case the two PPh 3 are cis to each other and that in the acentric triclinic cell there are two independent [Pd(H 2 O) 2 (PPh 3 ) 2 ] 2þ units, together with two methanesulfonato counter anions and two crystallization molecules of CH 2 Cl 2 . The cationic complexes Ia and IIa are easily interconverted with the neutral species trans-[Pd(p-CH 3 C 6 H 4 SO 3 ) 2 (PPh 3 ) 2 ] (Ib) and trans-[Pd(CH 3 SO 3 ) 2 (PPh 3 ) 2 ] (IIb), respectively, depending on temperature and solvent. In chloroform at r.t., complex Ia catalyzes the carbonylation of ethene to a polyketone; at higher temperature in methanol it catalyzes the hydroesterification of ethene. In both cases catalysis is accompanied by CO 2 evolution. These results suggest that catalysis occurs via initial formation of a Pd(II)-H species by interaction of H 2 O with CO on the metal center though a reaction closely related to that of the water gas-shift.

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Enabling Ligand Screening for Palladium‐Catalysed Enantioselective Aza‐Michael Addition Reactions

et al. 2006

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The bis(trifluoromethanesulfonate)palladium(II) dihydrate complex, Pd(OTf)2⋅2 H2O (1), is an active palladium(II) precursor for the generation of dicationic palladium(II) catalysts. Parallel ligand screening is enabled for the first time, and twenty‐four chiral ligands were evaluated for the asymmetric aza‐Michael addition of aromatic amines to α,β‐unsaturated N‐alkenoylimides and carbamates. Enantioselectivities of >99% can be obtained. Catalytic precursors generated from 1 using the new protocol have been identified.

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Preparation and X-ray Crystal and Molecular Structure of cis-[(dppp)Pd(H2O)(OSO2CF3)]+(OSO2CF3)- and cis-[(dppp)Pd(H2O)2]2+(OSO2CF3)-2 Coordinated Water-Triflate Hydrogen Bonds

Cited by 75 publications

References 0 publications

Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Synthesis, characterization and X-ray structure of [Pd(SO4)(dppp)]·H2O, a catalyst for the CO-ethene copolymerization [dppp=1,3-bis(diphenylphosphino)propane]

Synthesis, characterization and catalytic activity in the carbonylation of ethene of cis-[Pd(H2O)2(PPh3)2]X2·nH2O (X=p-CH3C6H4SO3, n=2; X=CH3SO3, n=0). X-ray structure of cis-Pd(H2O)2(PPh3)2](p-CH3C6H4SO3)2·2H2O and of cis-[Pd(H2O)2(PPh3)2](CH3SO3)2·2CH2Cl2

Enabling Ligand Screening for Palladium‐Catalysed Enantioselective Aza‐Michael Addition Reactions

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