1416162-95-2Relevant academic research and scientific papers
Syntheses, dynamic behaviour and theoretical studies of [(Piperidinomethyl)silyl]methyl-cyclopalladated dimetallic complexes
Colquhoun, Victoria P.,Schildbach, Daniel,Martin-Romo, Raquel,Strohmann, Carsten,Villafane, Fernando
, p. 3427 - 3434 (2012)
The cationic complex [Pd{CH2SiPh2(CH 2NC5H10)-κ2C,N}(NCMe) 2]BF4 (CH2NC5H10 = piperidinomethyl) is obtained from the reaction of [Pd{CH2SiPh 2(CH2NC5H10)-κ2C,N} (μ-Cl)]2 with TlBF4 in the presence of NCMe. It reacts with KO2CCH3 leading to the dimetallic complex [Pd{CH 2SiPh2(CH2NC5H10)- κ2C,N}(μ-O2CCH3-κO:κ'O)] 2, which exists only as the transoid isomer in solution. A dynamic process due to inversion of the acetato bridges is detected by variable-temperature 1H NMR spectroscopy. The reaction of the same parent complex with Kdmpz (dmpz = dimethylpyrazolate) leads to the dinuclear complex [Pd{CH2SiPh2(CH2NC5H 10)-κ2C,N}(μ-dmpz-κN:κ'N)] 2, which in solution exists as a mixture of cisoid and transoid isomers, but no inversion of the bridging pyrazolato groups has been observed. The reaction between equimolar amounts of these two complexes in CH 2Cl2 affords low yields of the expected mixed acetato/pyrazolato-bridged complex [Pd2{CH2SiPh 2(CH2NC5H10)-κ2C,N} 2(μ-O2CCH3-κO:κ'O)(μ-dmpz- κN:κ'N)]. The mixed chlorido-pyrazolato-bridged complex [Pd 2{CH2SiPh2(CH2NC5H 10)-κ2C,N}2(μ-Cl)(μ-dmpz-κN: κ'N)] is obtained by mixing equimolar amounts of the parent dichlorido- and bis(dimethylpyrazolato)-bridged dinuclear complexes, and exhibits a dynamic process in solution corresponding to the inversion of the bridges. Only the cisoid isomers are detected for both dimetallic complexes with mixed bridging ligands. The experimental findings of the preferred transoid or cisoid structure in these dinuclear Pd complexes were supported by quantum chemical calculations. The nature of the bridging ligands determines both the presence of transoid or cisoid isomers and the rigidity in solution of dimetallic complexes containing palladacycles with the [(piperidinomethyl)silyl]methyl ligand. Copyright
