Rigid bidentate nitrogen ligands in organometallic chemistry and homogeneous catalysis. 7. Stabilization of high oxidation states by rigid bidentate nitrogen ligands: synthesis and characterization of diorgano- and triorganopalladium(IV) and cationic triorganoplatinum(IV) complexes

Asselt, R. van; Rijnberg, Evelien; Elsevier, C. J.

doi:10.1021/om00014a049

Cited by 140 publications

(67 citation statements)

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“…The fact that the two sets of satellites have not coalesced establishes that rapid interconversion of axial and equatorial methyls does not occur on the measurement time scale in acetonitrile-d 3 . Similar dynamic behavior, temperature, and/or solvent effects have previously been observed for other ðNANÞPtMe þ 3 OTf À [19][20][21] complexes. In the present case, this behavior may be understood with Scheme 4 as the basis: In dichloromethane or chloroform solvents, acetonitrile dissociation leads to the five-coordinate intermediate in a medium that contains very little free acetonitrile.…”

Section: Preparative Worksupporting

confidence: 81%

Oxidatively induced reactions of a diimine platinum(IV) tetramethyl complex

Wik

Tilset

2007

Journal of Organometallic Chemistry

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Section: Preparative Worksupporting

confidence: 81%

Oxidatively induced reactions of a diimine platinum(IV) tetramethyl complex

Wik

Tilset

2007

Journal of Organometallic Chemistry

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“…[35] The capacity of this ligand type to support many oxidation states has been amply demonstrated; for example, Pt Ar-BIAN complexes have been reported in oxidation states ranging from Pt 0 [35] via Pt II [45] to Pt IV . [38] Ar-BIAN Pt complexes have found uses in catalytic hydrosilylation of styrene [49] and some complexes have interesting photophysical properties. [50][51][52] Surprisingly to us, to the best of our knowledge no reports have appeared on the use of Ar-BIAN ligand systems in studies of reactions of relevance to C-H bond activation.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Protonation Reactions of Ar‐BIAN and Ar‐BICAT Diimine Platinum Diphenyl Complexes

2010

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PtII diphenyl complexes (N–N)PtPh2 [N–N = diimines Ar–N=C(An)C=N–Ar with Ar = substituted aryl groups] have been prepared and characterized by 1H, 13C, and 195Pt NMR spectroscopy. The 195Pt NMR spectroscopic data establish the electronic influence exerted by substituents at the backbone of the diimine ligand system to the metal center. When compared to diimines Ar–N=CMe–CMe=N–Ar, the electron‐withdrawing ability of the Ar‐BIAN ligand and the electron‐donating ability of the O,O‐heterocyclic Ar‐BICAT systems are demonstrated. Trends in 195Pt NMR chemical shifts suggest that electronic tuning of the metal center is better achieved through variations of the diimine backbone substituents rather than variation of the substituents at the N‐Aryl groups. Protonation of (N–N)PtPh2 in dichloromethane/acetonitrile at –78 °C furnishes the corresponding PtIV hydrides (N–N)PtPh2H(NCMe)+. The PtIV hydrides liberate benzene with the formation of (N–N)PtPh(NCMe)+ when the temperature is raised. A second protonation and rapid benzene elimination produces the dicationic PtII species (N–N)Pt(NCMe)22+ at approximately 50 °C. Protonation of (N–N)PtPh2 in the absence of acetonitrile results in the clean formation of (N–N)PtPh(η2‐C6H6)+ at temperatures that depend on the steric hindrance provided by the alkyl substituents at the diimine N‐aryl groups. These findings support the notion that the metal is the kinetically preferred site of protonation. The results qualitatively agree with a recent mechanistic study of protonation‐induced reactions of (diimine)PtPh2 complexes that bear simple methyl substituents at the diimine backbone. Several compounds have been crystallographically characterized. All complexes have the expected square planar environment at the metal. Modest variations in the metric parameters suggest that the Ar‐BICAT system has a weaker trans influence than the Ar‐BIAN and Ar‐DAB systems.

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“…The resulting coordination complexes have been utilized in organic synthesis and catalysis (13)(14)(15)(16)(17)(18)(19)(20) and as luminescence labels for the detection and photochemical cleavage of DNA (21). Diazabutadienes have also been used in dehalosilylation -ring-closure reactions of SbCl 3 and BiCl 3 to give the corresponding 1,2,5-pnictadiazoles (22).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and reactivity of palladium and platinum diimine complexes containing boronate esters

King¹,

Nikolcheva²,

Graves³

et al. 2002

Can. J. Chem.

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Condensation of a-diketones (2,3-butanedione, benzil, and acenaphthenequinone) with 3-H 2 NC 6 H 4 Bpin (pin = 1,2-O 2 C 2 Me 4 ) gave the corresponding boron-containing a-diimines. The addition of these ligands to [MCl 2 (coe)] 2 (coe = cis-cyclooctene, M = Pd or Pt) gave complexes of the type cis-MCl 2 (a-diimine) in moderate to high yields. The platinum complexes have been examined for their ability to bind to DNA using enzyme digest studies. These complexes were found to bind to single-stranded DNA as well as, or better than, the non-boron containing controls, and showed binding similar to that of cisplatin (cis-PtCl 2 (NH 3 ) 2 ).Résumé : La condensation d'a-dicétones (butane-2,3-dione, benzile, et acénaphtènequinone) avec le 3-H 2 NC 6 H 4 Bpin (pin = 1,2-O 2 C 2 Me 4 ) conduit à la formation d'a-diimines contenant du bore. L'addition de ces ligands au [MCl 2 (coe)] 2 (coe = cis-cyclooctène; M = Pd, Pt) fournit des complexes du type cis-MCl 2 (a-diimine) avec des rendements allant de modérés à élevés. Faisant appel à des études de digestion d'enzymes, on a évalué la capacité de ces complexes du platine à se fixer sur l'ADN. Vis-à-vis de l'ADN à brin unique, ces complexes se fixent aussi bien, ou mieux, que les contrôles ne contenant pas de bore et leur taux de fixation est semblable à celui du cisplatine, cis-PtCl 2 (NH 3 ) 2 .

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Rigid bidentate nitrogen ligands in organometallic chemistry and homogeneous catalysis. 7. Stabilization of high oxidation states by rigid bidentate nitrogen ligands: synthesis and characterization of diorgano- and triorganopalladium(IV) and cationic triorganoplatinum(IV) complexes

Cited by 140 publications

References 0 publications

Oxidatively induced reactions of a diimine platinum(IV) tetramethyl complex

Oxidatively induced reactions of a diimine platinum(IV) tetramethyl complex

Synthesis, Characterization, and Protonation Reactions of Ar‐BIAN and Ar‐BICAT Diimine Platinum Diphenyl Complexes

Synthesis and reactivity of palladium and platinum diimine complexes containing boronate esters

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