69258-10-2Relevant academic research and scientific papers
Modular Design Strategy toward Second-Generation Tridentate Carbodiphosphorane N,C,N Ligands with a Central Four-Electron Carbon Donor Motif and Their Complexes
Klein, Marius,Sundermeyer, J?rg
, p. 2090 - 2099 (2021)
The reaction of sym-bis(P-chlorodiphenyl)carbodiphosphorane (1) with difunctional nucleophiles leads to carbodiphosphoranes carrying two additional chelating N-donor functionalities. A proof of concept is demonstrated by the synthesis and characterization of sym-bis(3,5-dimethyl-1H-pyrazol-1-yl)carbodiphosphorane (CDP(3,5-MePz)2, 2) and sym-bis(pyridin-2-yloxy)carbodiphosphorane (CDP(O-2Py)2, 3). Due to their superbasic central two-/four-electron carbon donor functionality, these neutral ligands are electronically flexible to act as neutral six- or eight-electron donors, as pincer ligand templates, or as two geminally metal bridging ligands. Their potential to form mono- and dinuclear complexes involving two 6-ring or two 5-ring N,C-chelate ring motives has been explored. Complexes of 2 and 3 with fac-[M(CO)3] fragments (ls d6 M = Cr, Mo, W) were used as spectroscopic probes. They reveal a strong σ-donor and potential π-donor ability of the central carbon donor pushing electron density for enhanced M-CO back-bonding into the metal d orbitals. DFT calculations consolidate this observation. Dinuclear and multinuclear d10 Cu(I) complexes have been formed and structurally investigated upon treating these CDP ligands 2 and 3 with CuX (X = Cl, Br, I).
Silyl group migration in a P-silylated phosphonium ylide derived from dppm - A combined experimental and theoretical study
Langer, Jens,Pálfi, Vill? K.,Schowtka, Bj?rn,G?rls, Helmar,Reiher, Markus
, p. 28 - 31 (2013/07/19)
The lithium complex [(Et2O)2Li{(Ph2P) 2CH}] (2) was synthesized by recrystallization of the corresponding solvent-free complex in diethyl ether. The kinetic product of the reaction of 2 and Me3SiCl, Ph2PCHP(SiMe3)Ph2 (3), was isolated under appropriate conditions and characterized by NMR measurement at 228 K. Both, reversible P-to-P and irreversible P-to-C migration of the silyl group were observed at higher temperatures and investigated by NMR techniques and quantum chemical calculations. The thermodynamic product Ph 2PCH(SiMe3)PPh2 (1) was found to be 84 kJ mol- 1 (B97-D/TZVPP) lower in energy than the kinetic product 3. The molecular structures of 1-3 were determined by X-ray diffraction measurement.
