Synthesis and Characterization of Tantalum-Based Early-Late Heterobimetallic Complexes Supported by 2-(diphenylphosphino)pyrrolide Ligands

Comparative Analysis of the Donor Properties of Isomeric Pyrrolyl Phosphine Ligands

Understanding the net donor and electronic properties of pyrrole-based phosphines is critical for guiding their use as ligands. In this study, we compare two isomeric 1- and 2-(diphenylphosphino)methylpyrroles (L1 and L2, respectively) to determine the degree to which N-(phosphino)pyrroles are distinct from aryl- and 2-pyrrolyl phosphines. Ruthenium, rhodium, platinum, and gold complexes as well as selenide derivatives of these ligands are examined using NMR and IR spectroscopy, X-ray crystallography, and cyclic voltammetry. Ligand L2 exhibits net donor properties similar to those of the o-tolyl analogue L3, while L1 shows attenuated electron donation ability. Additionally, a model nickel-catalyzed Kumada coupling reaction using these three ligands was investigated.

Synthesis of pyrrole-based PSiP pincer ligands and their palladium, rhodium, and platinum complexes

The synthesis and coordination chemistry of a new class of silyl pincer ligand featuring pyrrole-based linkers is reported. The steric and electronic properties of these bis(phosphinopyrrole)methylsilane ligands were interrogated using their palladium, rhodium, and platinum complexes. The pyrrole-based linker attenuates the donor ability of the ligand relative to its reported 1,2-phenylene congener while maintaining a similar steric profile. Additionally, the silyl donor connected to the N-pyrrolyl groups exhibits a weaker trans influence than the analogous ligand featuring 1,2-phenylene linkers.

H2 and carbon-heteroatom bond activation mediated by polarized heterobimetallic complexes

The field of heterobimetallic chemistry has rapidly expanded over the last decade. In addition to their interesting structural features, heterobimetallic structures have been found to facilitate a range of stoichiometric bond activations and catalytic processes. The accompanying review summarizes advances in this area since January of 2010. The review encompasses well-characterized heterobimetallic complexes, with a particular focus on mechanistic details surrounding their reactivity applications.

Mechanistic investigations via DFT support the cooperative heterobimetallic C-H and O-H bond activation across Ta[double bond, length as m-dash]Ir multiple bonds

A rare heterobimetallic oxidative addition of X-H (X = C, O) bonds is reported. DFT suggests that steric constraints around the bimetallic core play a critical role to synergistically activate C-H bonds across the two metals and thus explains the exceptional H/D exchange catalytic activity of unhindered surface organometallic Ta/Ir species observed experimentally.

Ni complexes of an alane/tris(phosphine) ligand built around a strongly Lewis acidic tris(N-pyrrolyl)aluminum

Syntheses of a new tripodal alane/tris(phosphine) ligand (AlP₃) based on 2-(diisopropylphosphino)pyrrole, and AlP₃-supported Ni complexes are reported.