13433-37-9Relevant academic research and scientific papers
Effective Control of the Electron-donating Ability of Phosphines by using Phosphazenyl and Phosphoniumylidyl Substituents
Werra, Janina A.,Wünsche, Marius A.,Rathmann, Patrick,Mehlmann, Paul,L?we, Pawel,Dielmann, Fabian
supporting information, p. 794 - 799 (2020/04/29)
Phosphoniumylidyl and phosphazenyl groups are effective substituents to increase the electron-donating ability of tertiary phosphines. However, the influence of structural variations among those substituents on the electronic properties of the phosphines is little explored. Herein, we show that protonation of the ylidic carbon atom of phosphoniumylidyl phosphines increases the Tolman electronic parameter (TEP) by ΔTEP = 16.0–18.8 cm–1. Furthermore, phosphazenyl phosphines were synthesized with isopropyl groups (NP{iPr}3) and tetramethylguanidino groups (NP{tmg}3) at the phosphonium center. Determination of their TEP values reveals a remarkable low substituent parameter of χ = –18.5 cm–1 for the NP(tmg)3 group. In addition, we prepared the corresponding gold(I) complexes and determined their solid-state structures using single-crystal X-ray diffraction studies to analyze the steric profile of the new phosphine ligands.
Contributions to the Synthesis and Structure of Tris(phosphonium) Methanide Salts and Their Precursors
Schmidbaur, Hubert,Strunk, Sven,Zybill, Christian E.
, p. 3559 - 3566 (2007/10/02)
The addition product of hexaphenylcarbodiphosphorane (1) and chlorodiphenylphosphane of the formula (+) Cl(-) (7) was found to have inequivalent Ph3P groups by 31P NMR spectroscopy in solution at low temperatures, due to restricted rotation of the Ph2P group.The ground state corresponds to a conformation with the lone pair of electrons at P(III) in the P3C plane.- The dication (2+) is obtained, as the diiodide 10, from MePh2P=CH2 and Ph2PCl followed by CH3I.In 10 all three MePh2P groups are equivalent (C3h-symmetry). (2+) 2I(-) (11) is prepared through CH3I addition to 7, (+) I(-) (13) and (2+) 2I(-) (12) from 8 and CH3I.- Cyclic tris(phosphonium)methanides 14-16 are formed from 8 and 1,3-dibromopropane, 1,4-dibromobutane, and 1,2-bis(chloromethyl)benzene, respectively.The analogous process with 8 and 1,4-dibromo-2-butene yields a product 17 with a vinyl-substituted 1,3-diphospholane system.
