Nickel(II) carbonyl, ammonia, and acetonitrile complexes supported by a pyridine dipyrrolide pincer ligand

Abstract

The synthesis, isolation and crystal structures of nickel(II) carbonyl, acetonitrile and ammonia complexes supported by a dianionic, pyridine dipyrrolide pincer ligand [pyrr2py]2−, namely, carbonyl[2,2′-(pyridine-2,6-diyl)bis(3,5-di-p-tolylpyrrolido-κN)]nickel(II), [Ni(C41H33N3)(CO)], ammine[2,2′-(pyridine-2,6-diyl)bis(3,5-di-p-tolylpyrrolido-κN)]nickel(II), [Ni(C41H33N3)(NH3)], and (acetonitrile-κN)[2,2′-(pyridine-2,6-diyl)bis(3,5-di-p-tolylpyrrolido-κN)]nickel(II), [Ni(C41H33N3)(CH3CN)], as well as the free ligand 2,6-bis(3,5-di-p-tolylpyrrol-2-yl)pyridine, C41H35N3 or [pyrr2py]H2 are reported. The nickel complexes are four-coordinate and adopt a square-planar geometry. The CO stretch of the nickel-bound carbon monoxide ligand of [pyrr2py]Ni(CO) has been observed at 2101 cm−1. The ammonia and acetonitrile complexes, [pyrr2py]Ni(NH3) and [pyrr2py]Ni(NCMe) feature all-nitrogen coordination spheres around nickel consisting of different N-donor ligand types.

Synthesis and Characterization of Pyridine Dipyrrolide Uranyl Complexes

“…Of late, a new family of tridentate pincer ligands, so called pyridine dipyrrolides (PDPs) in their dianionic, doubly deprotonated form (PDP 2– ), has garnered widespread attention in both transition metal and main group chemistry. − Because H 2 PDP proligands are prepared in a modular fashion, the corresponding PDP 2– ligands are well suited for the manipulation of specific steric and electronic profiles of coordinated metals. With this in mind, researchers have leveraged PDP metal complexes in catalysis, atom and group transfer, ,, and photochemistry. − Despite this expanding wealth of research, PDP compounds of either lanthanide or actinide elements have not been reported …”