167171-03-1Relevant articles and documents
Copper(I) Phosphinooxazoline Complexes: Impact of the Ligand Substitution and Steric Demand on the Electrochemical and Photophysical Properties
Frey, Wolfgang,Giereth, Robin,Karnahl, Michael,Klo?, Marvin,Mengele, Alexander K.,Steffen, Andreas,Tschierlei, Stefanie
, p. 2675 - 2684 (2020/03/04)
A series of seven homoleptic CuI complexes based on hetero-bidentate P^N ligands was synthesized and comprehensively characterized. In order to study structure–property relationships, the type, size, number and configuration of substituents at the phosphinooxazoline (phox) ligands were systematically varied. To this end, a combination of X-ray diffraction, NMR spectroscopy, steady-state absorption and emission spectroscopy, time-resolved emission spectroscopy, quenching experiments and cyclic voltammetry was used to assess the photophysical and electrochemical properties. Furthermore, time-dependent density functional theory calculations were applied to also analyze the excited state structures and characteristics. Surprisingly, a strong dependency on the chirality of the respective P^N ligand was found, whereas the specific kind and size of the different substituents has only a minor impact on the properties in solution. Most importantly, all complexes except C3 are photostable in solution and show fully reversible redox processes. Sacrificial reductants were applied to demonstrate a successful electron transfer upon light irradiation. These properties render this class of photosensitizers as potential candidates for solar energy conversion issues.
In situ enzymatic screening (ISES) of P,N-ligands for Ni(0)-mediated asymmetric intramolecular allylic amination
Berkowitz, David B.,Shen, Weijun,Maiti, Gourhari
, p. 2845 - 2851 (2007/10/03)
An in situ enzymatic screening (ISES) approach to rapid catalyst evaluation recently pointed to Ni(0) as a new candidate transition metal for intramolecular allylic amination. This led to further exploration of chiral bidentate phosphine ligands for such transformations. Herein, a variety of P,N-ligands are examined for this Ni(0)-chemistry, using a model reaction leading into the vinylglycinol scaffold. On the one hand, an N,N-bis(2-diphenylphosphinoethyl)alkylamine ('PNP') ligand proved to be the fastest ligand yet seen for this Ni(0)-transformation. On the other, phosphinooxazoline (PHOX) ligands of the Pfaltz-Helmchen-Williams variety gave the highest enantioselectivities (up to 51% ee) among P,N-ligands examined.
