ABSTRACT
Homogenous catalysis is an essential tool within the commercial manufacture of bulk and fine chemicals. Within this, phosphine ligands, such as tricyclohexylphosphine, otherwise known as CYTOP® 366, are a crucial component. When designing a pathway to your ligand of choice, some key considerations include safety, yield and quality, but at commercial volumes we must also balance cost and consider the technologies readily available. Herein, we report the synthetic route that was chosen to manufacture tricyclohexylphosphine at commercial scale. We also consider, with the use of computational calculations, why traditional hydrophosphination methods failed, where the selected pathway succeeded.
ABSTRACT
The chemical composition of the solid electrolyte interphase (SEI) layer formed on the surface of lithium metal electrodes cycled in phosphonium bis(fluorosulfonyl)imide ionic liquid (IL) electrolytes are characterized by magic angle spinning nuclear magnetic resonance (MAS NMR), X-ray photoelectron spectroscopy (XPS), fourier transformed infrared spectroscopy, and electrochemical impedance spectroscopy. A multiphase layered structure is revealed, which is shown to remain relatively unchanged during extended cycling (up to 250 cycles at 1.5 mA·cm-2, 3 mA h·cm-2, 50 °C). The main components detected by MAS NMR and XPS after several hundreds of cycles are LiF and breakdown products from the bis(fluorosulfonyl)imide anion including Li2S. Similarities in chemical composition are observed in the case of the dilute (0.5 mol·kg-1 of Li salt in IL) and the highly concentrated (3.8 mol·kg-1 of Li salt in IL) electrolyte during cycling. The concentrated system is found to promote the formation of a thicker and more uniform SEI with larger amounts of reduced species from the anion. These SEI features are thought to facilitate more stable and efficient Li cycling and a reduced tendency for dendrite formation.
ABSTRACT
[structure: see text] Phosphorinanes are presented as a class of phosphine ligand suitable for organopalladium cross-coupling chemistry. Prepared via a direct double Michael addition of a monoalkyl- or arylphosphine to phorone followed by a Wolf-Kishner reduction, phosphorinanes are relatively inexpensive to manufacture and allow modification of one of the alkyl moieties permitting steric and electronic fine-tuning of the ligands. Library screening and applications of these ligands in the Suzuki, Sonogashira, ketone arylation, and aryl amination reactions are presented.