Novel Route to Cationic Palladium(II)-Cyclopentadienyl Complexes Containing Phosphine Ligands and Their Catalytic Activities

• Published in: Molecules (Basel, Switzerland) Switzerland), 2023-05, Vol.28 (10), p.4141
• Main Authors: Suslov, Dmitry S, Bykov, Mikhail V, Pakhomova, Marina V, Orlov, Timur S, Abramov, Zorikto D, Suchkova, Anastasia V, Ushakov, Igor A, Abramov, Pavel A, Novikov, Alexander S
• Format: Article
• Language: English
• Subjects: 1,3-butadiene; acetylacetonate; Butadiene; Carbon; Catalysts; Cations; cyclopentadienyl; Hexanes; Inspection; Ligands; Metallocenes; Palladium; Pentane; phenylacetylene; Polymerization; telomerization; Transition metal compounds
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28104141

The Pd(II) complexes [Pd(Cp)(L) ] [BF ] were synthesized via the reaction of cationic acetylacetonate complexes with cyclopentadiene in the presence of BF ∙OEt ( = 2, = 1: L = PPh ( ), P( -Tol) , ( -methoxyphenyl)phosphine (TOMPP), -2-furylphosphine, -2-thienylphosphine; = 1, = 1: L = dppf, dppp ( ), dppb ( ), 1,5-bis(diphenylphosphino)pentane; = 1, = 2 or 3: 1,6-bis(diphenylphosphino)hexane). Complexes - were characterized using X-ray diffractometry. The inspection of the crystal structures of the complexes enabled the recognition of (Cp )⋯(Ph-group) and (Cp )⋯(CH -group) interactions, which are of C-H…π nature. The presence of these interactions was confirmed theoretically via DFT calculations using QTAIM analysis. The intermolecular interactions in the X-ray structures are non-covalent in origin with an estimated energy of 0.3-1.6 kcal/mol. The cationic palladium catalyst precursors with monophosphines were found to be active catalysts for the telomerization of 1,3-butadiene with methanol ( up to 2.4∙10 mol 1,3-butadiene per mol Pd with chemoselectivity of 82%). Complex [Pd(Cp)(TOMPP) ]BF was found to be an efficient catalyst for the polymerization of phenylacetylene (PA) (catalyst activities up to 8.9 × 10 g ·(mol ·h) were observed).