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

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.