Supramolecular bulky phosphines comprising 1,3,5-triaza-7-phosphaadamantane and Zn(salphen)s: structural features and application in hydrosilylation catalysis

International audienceThe use of the commercially available, bifunctional phosphine 1,3,5-triaza-7-phosphaadamantane (abbreviated as PN 3) in conjunction with a series of Zn(salphen) complexes leads to sterically encumbered phosphine ligands as a result of (reversible) coordinative Zn–N interactions. The solid state and solution phase behaviour of these supramolecular ligand systems have been investigated in detail and revealed their stoichiometries in the solid state observed by X-ray crystallography, and those determined in solution by NMR and UV-Vis spectroscopy. Also, upon application of these supramolecular bulky phosphines in hydrosilylation catalysis employing 1-hexene as a substrate, the catalysis data infer the presence of an active Rh species with two coordinated, bulky PN 3 /Zn(salphen) assembly units having a maximum of three Zn(salphen)s associated per PN 3 scaffold, with an excess of bulky phosphines hardly affecting the overall activity

Synthesis and Characterization of Platinum(II)-Terminated Dendritic Carbosilanes. X-ray Molecular Structure and Isomerization Behavior of the Model Species [PtCl(C6H3{CH2NMe2}-2-SiMe3-5)(PPh3)]

A series of cycloplatinated carbosilane dendrimers appended with the monoanionic C, N-bidentate ligand [C{6}H{4}{CH{2}NMe{2}}-2]}-{ (CN) was prepared via a multiple C@?H activation reaction. Ligand exchange in the parent model species [PtCl(C{6}H{3}{CH{2}NMe{2}}-2-SiMe{3}-5)(DMSO)] (1) in the presence of PPh{3} gave the phosphine complex [PtCl(C{6}H{3}{CH{2}NMe{2}}-2-SiMe{3}-5)(PPh{3})] (2). The crystal structure of 2 was also determined, showing a close proximity between one of the Ar@?H of the phosphine ligand and the Ar@?H{o}{r}{t}{h}{o} of the CN ligand

Metal-Directed Self-Assembly of a ZnII-salpyr Complex into a Supramolecular Vase Structure

A new type of supramolecular building block, ZnII-salpyr [salpyr = N,N'-3-pyridylenebis(salicylideneimine)], is described that contains both a pyridyl donor and a Lewis acidic ZnII acceptor site in the salen framework. As a consequence, this building block self-organizes into a stable tetrameric vase structure via cooperative intermolecular Zn-Npyr interactions