PPX/PXP-type ligands (X = O and S) and their transition metal complexes: synthesis, properties and applications.

Short-bite diphosphines of the form RP-X-PR (PXP; X = O, S; R = aryl, alkyl), incorporating an oxygen or sulphur atom as bridging unit X, are widely underexplored compared to their N- and C-containing PNP- and PCP-type counterparts. However, these PXP ligands undergo an interesting phosphorotropic equilibrium with the PPX (RP(X)-PR) tautomer, which opens up a very versatile coordination chemistry. This article covers the impact of the ligand backbone in short-bite ligands on their coordination chemistry, reactivity and applications.

Support Engineering for the Stabilisation of Heterogeneous Pd P-Based Catalysts for Heck Coupling Reactions.

Herein we report the use of a supported Pd P catalyst for Heck coupling reactions. For the stabilisation of Pd P and Pd, as reference system, the silica support material was modified via phosphorus doping (0.5 and 1 wt % P).

Acute Bite Angle POP- and PSP-Type Ligands and Their Trinuclear Copper(I) Complexes: Synthesis and Photo-Luminescence Properties.

In the current work, the rational synthesis of trinuclear copper complexes, incorporating acute bite angle POP- and PSP-type ligands, is reported. The in situ formation of POP (PhP-O-PPh) or PSP (PhP-S-PPh) ligands in the presence of a copper(I) precursor gave access to various trinuclear copper complexes of the form [Cu(μ-Hal)(μ-PXP)]PF [X = O; Hal = Cl (), Br (), I () and X = S; Hal = Cl (), Br (), I ()]. Related iodide-containing complexes and clusters, such as [Cu(μ-I)(PhPI)] () and [Cu(μ-I)(μ-I)(μ-PSP)] (), could also be obtained via the variation of the reaction stoichiometry.

A Supported Palladium Phosphide Catalyst for the Wacker-Tsuji-Oxidation of Styrene.

The substitution of pure metal particles by metal phosphides in catalysis represents a promising opportunity to lower the required metal quantity in the context of a sustainable use of metal resources. Herein we show the synthesis of palladium phosphide, Pd P, supported on silica, which is tested as catalyst for the Wacker-Tsuji-oxidation of styrene to acetophenone. The synthesized catalyst is characterized by PXRD, SEM-EDX, FTIR, ICP-AES and XPS measurements.

Transition metal complexes of the PPO/POP ligand: variable coordination chemistry and photo-luminescence properties.

In the current work the tautomeric equilibrium between tetraphenyldiphosphoxane (PhP-O-PPh, POP) and tetraphenyldiphosphine monoxide (PhP-P(O)Ph, PPO) in the absence and presence of transition metal precursors is investigated. Whereas with hard transition metal ions, such as Fe(II) and Y(III), PPO-type complexes, such as [FeCl(PPO)] (1) and [YCl(THF)(PPO)] (2), are formed, softer transition metals ions tend to form so-called coordination stabilised tautomers of the POP ligand form, such as [Cu(MeCN)(μ-POP)](PF) (3), [AuCl(μ-POP)] (4), and [Au(μ-POP)](OTf) (5). The photo-optical properties of the PPO- and POP-type transition metal complexes are investigated experimentally using photo-luminescence spectroscopy, whereby the presence of metallophillic interactions was found to play a crucial role.

Amylose-Coated Biohybrid Microgels by Phosphorylase-Catalyzed Grafting-From Polymerization.

Herein, the synthesis of amylose-coated, temperature-responsive poly(N-vinylcaprolactam) (VCL)-based copolymer microgels by enzyme-catalyzed grafting-from polymerization with phosphorylase b from rabbit muscle is reported. The phosphorylase is able to recognize the oligosaccharide maltoheptaose as primer and attach glucose units from the monomer glucose-1-phosphate to it, thereby forming amylose chains while releasing inorganic phosphate. Therefore, to enable the phosphorylase-catalyzed grafting-from polymerization of glucose-1-phosphate from the PVCL-based microgels, the maltoheptaose primer is covalently attached to the microgel in the first synthesis step.