Carbon-13 nuclear magnetic resonance studies of platinum(II) olefin bonds

Cooper, David G.; Powell, John Wesley

doi:10.1021/ic50162a044

Cited by 55 publications

(15 citation statements)

References 16 publications

(21 reference statements)

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“…These results are consistent with those reported for the relative thermodynamic stabilities of 4-substituted-styrene complexes of Pt(II) in solution 1201. But they are in contrast to that, expected from 13C NMR data reported on a series of styrene complexes where it was found that the coupling constants between Pt and the olefinic carbons increased with the electron-donating strength of the 4-substituent of styrene [21,22]. It is known, however, that the coupling constant is insensitive to the strength of the r back-bonding in these complexes [21].…”

Section: Et Zellers and G-z Zhang/anal Chim Acta 280 (1993) L-13contrasting

confidence: 68%

Influence of substituent and ligand electronic factors on the measurement of gas phase olefins using a surface acoustic wave oscillator coated with trans-PtCl2(olefin)(amine) complexes

Zellers

Zhang

1993

Analytica Chimica Acta

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Certain olefin gases and vapors can be measured selectively at low concentrations using surface acoustic wave (SAW) sensors vated with reagents of the general formula trans-PtClz(olefin)(amine). The sensor response depends on the steady-state rate of mass change associated with substitution of the initially complexed olefin by the free olefin analyte. This paper examines the effects of changes in the electronic nature of substituents on the free olefin and the olefin and amine ligands in the complex on the sensitivity and selectivity obtained with this class of SAW sensor coatings. For a given reagent, higher reaction rates are generally observed with electron-donating substituents on the double bond of the free olefin. For a given free olefin, varying the 4-substituent of the pyridine ligand in PtCl,(ethyleneX4-X-pyridine)gives a maximum response at an intermediate degree of amine basicity. Replacing pyridine by aniline, pyridine N-oxide or the 4-substituted derivatives of these ligands results in reduced responses for the olefins tested. Changing the initially complexed olefin leads to large changes in response, the pattern of which varies with the nature of the free olefin. Results demonstrate the potential for controlling the response of SAW sensors through subtle structural modifications of these coating reagents.

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Section: Et Zellers and G-z Zhang/anal Chim Acta 280 (1993) L-13contrasting

confidence: 68%

Influence of substituent and ligand electronic factors on the measurement of gas phase olefins using a surface acoustic wave oscillator coated with trans-PtCl2(olefin)(amine) complexes

Zellers

Zhang

1993

Analytica Chimica Acta

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“…NMR spectrometry is a very sensitive tool which can determine the electron density of nucleus in organic as well as organometallic compounds. Certain Pd-styrene and Pt-styrene complexes have been studied by NMR spectroscopic technique (3)(4)(5)(6). The correlation between Hammett constants (a,, or u', a-) and AS for neutral, anionic and cationic Pt-styrenes were reported (4).…”

Section: Introductionmentioning

confidence: 99%

“…Certain Pd-styrene and Pt-styrene complexes have been studied by NMR spectroscopic technique (3)(4)(5)(6). The correlation between Hammett constants (a,, or u', a-) and AS for neutral, anionic and cationic Pt-styrenes were reported (4). We took advantage of this relationship in our study to investigate the substituent dependency of the bonding of styrenes with ruthenium and osmium, we have also used voltammetric analysis in our study.…”

Section: Introductionmentioning

confidence: 99%

“…2). The n+ or a-parameters are used for a better correlation with AA6 indicating that the resonance effects are imporsubstituents of the styrene rather than ring coordination, hs tant for the 0 s series (10 shown by neutral and cationic Pt-styrene complexes (4). The of and a-values are larger than that from ethylbenzenes (1 1) ethenylbenzenes (12).…”

Section: Introductionmentioning

confidence: 99%

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Substituent dependency in pentaamminemetal(II) complexes (M = Ru, Os) of styrenes probed by using carbon-13 nuclear magnetic resonance spectroscopic method and voltammetrical analysis

Lin¹,

Jong²

1994

Can. J. Chem.

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SHAW-TAO LIN and JIN-TSUEY JONG. Can. J. Chem. 72, 1946Chem. 72, (1994.The I3c NMR spectra of [~(NH,),(st~rene)]'+ (M = Ru, 0s) demonstrate the substituent dependency of the interaction between the vinyl group and the metal moiety which suggests the modes of bonding. This phenomenon is also observed from the voltammetric analytical results which confirm the substituent dependency of the oxidation potential.

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“…This decrease was consistent with the metal in the allyl complexes being Pt(II) rather than Pt(0), with less electron-density being available and therefore weaker bonds to the allyl system than to the alkene ligands. 140,[149][150][151] In 11a, which was also Pt(II) with the c Pr ring trans to P, the 1 J Pt-C of the c Pr allyl carbon (447. 4 Hz) was also larger than for 13, though that of 11b, with the c Pr trans to C, was lower (202.…”

Section: Nmr Characterisationmentioning

confidence: 99%

Platinum Complexes of Bicyclopropylidene and Related Ligands

Hoyte¹

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<p>The coordination chemistry of the cyclopropyl-substituted alkenes, bicyclopropylidene (BCP) and methylenecyclopropane (MCP), with platinum was explored. A range of complexes with ŋ²-alkene ligands were synthesised by the displacement of a ligand, typically ethene, from a precursor complex. These complexes are [Pt(L)(P—P)] (L = BCP, MCP; P—P = Ph₂P(CH₂)₃PPh₂, Cy₂P(CH₂)₂PCy₂, ᵗBu₂P(CH₂)₂PᵗBu₂, ᵗBu₂PCH₂(o-C₆H₄)₂PᵗBu₂), [Pt(L)(P—S)] (L = BCP, MCP; P—S = ᵗBu₂PCH₂(o-₆H4)CH₂SᵗBu), [Pt(C₂H4)(L)(PR₃)] (L = BCP, MCP; PR₃ = PPh₃, PCy₃), [Pt(MCP)₂(PR₃)] (PR₃ = PPh₃, PCy₃) and [PtCl₂(L)(L′)] (L = BCP, MCP; L′ = Py, DMSO). These were the first examples of platinum complexes with ŋ²-BCP ligands, and the first bis-MCP Pt complexes. BCP underwent ring-opening reactions with both Pt(0) and Pt(II) complexes to form the 1,3-diene allylidenecyclopropane (ACP). The first transition metal complexes of ACP [Pt(ACP)(P—P)] (P—P = Ph₂P(CH₂)₃PPh₂, Cy₂P(CH₂)₂PCy₂, ᵗBu₂P(CH₂)₂PᵗBu₂) were synthesised. Some of these complexes rearranged to form ŋ²:σ²-metallacyclopentene complexes, the first instances of the formation of ŋ²:σ²-metallacyclopentene complexes from ŋ²:π-diene complexes. With MCP, the ring-opening reaction only occurred with [₂(COD)], as a result of the anti-Markovnikov addition of Pt–H, generated by the β-hydride elimination of an Et group, across the double-bond. The major products of this reaction were the 1-methylcyclopropyl complexes [Pt(C(CH₂)₂CH₃)Et(COD)] and [Pt(C(CH₂)₂CH₃)₂(COD)], the first examples of such complexes. Protonation of [Pt(L)(P—P)] resulted in a ring-opening reaction to form both the 2-substituted and 1-methyl allyl complexes, [Pt(ŋ³-CH₂CRCH₂)(P—P)]⁺ (R = ᶜPr, Me; P—P = Ph₂P(CH₂)₃PPh₂, ᵗBu₂PCH₂(o-C₆H₄)CH₂PᵗBu₂) and [Pt(ŋ³-CR₂CHCHMe)(P—P)]⁺ (R = cPr, Me; P—P = Ph₂P(CH₂)₃PPh₂, ᵗBuPCH₂(o-C₆H₄)CH₂PᵗBu₂). The analogous 1-methyl complexes were also formed from [Pt(L)(P—S)], wherein the alkene reacted with a hydride formed by the ortho-metallation of the P—S ligand. Computational models were used to investigate the formation of the allyl structures and it was found that the activation energy had a more significant effect than complex stability on product distributions. Complexes with β-chloroalkyl ligands [Pt(C(CH₂)₂CR₂Cl)Cl(L)₂] (R = CH₂, H, L = SEt₂, NCᵗBu, Py) were formed by the addition of Pt–Cl across the alkene double bond. Phosphine complexes were formed by the displacement of a ligand from cis–[Pt(C(CH₂)₂CR₂Cl)Cl(Py)₂] (R = CH₂, H). These are the first examples of stable Pt(II) β-haloalkyl complexes. It was found using computational models that the presence of cyclopropyl rings had a stabilising effect on these complexes.</p>

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Carbon-13 nuclear magnetic resonance studies of platinum(II) olefin bonds

Cited by 55 publications

References 16 publications

Influence of substituent and ligand electronic factors on the measurement of gas phase olefins using a surface acoustic wave oscillator coated with trans-PtCl2(olefin)(amine) complexes

Influence of substituent and ligand electronic factors on the measurement of gas phase olefins using a surface acoustic wave oscillator coated with trans-PtCl2(olefin)(amine) complexes

Substituent dependency in pentaamminemetal(II) complexes (M = Ru, Os) of styrenes probed by using carbon-13 nuclear magnetic resonance spectroscopic method and voltammetrical analysis

Platinum Complexes of Bicyclopropylidene and Related Ligands

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