Phosphanyl-Amino Complexes of Nickel(II): Synthesis and Structure

Abstract

New neutral pentacoordinate nickel(II) complexes of the type [NiCl2(PR3)(P∩N)] [PR3 = PMe3, PMe2Ph, PMePh2; P∩N = 2‐(diphenylphosphanyl)aniline (P∩NH2), N‐methyl‐2‐(diphenylphosphanyl)aniline (P∩NHMe), N,N‐dimethyl‐2‐(diphenylphosphanyl)aniline (P∩NMe2)], as well as cationic tetracoordinate nickel(II) complexes of the type [NiCl(PR3)(P∩N)]+ have been synthesized and characterized both in the solid state and in solution. Interesting X‐ray structural data have been collected for each class of compounds, which show, inter alia, that the pentacoordinate neutral complexes can be isolated in two different molecular forms, namely square‐pyramidal or bipyramidal‐trigonal.

Telomerization: Advances and Applications of a Versatile Reaction

“…Because of their high performance compared to classical phosphine ligands, carbene complexes are very interesting catalysts for industrial telomerization processes. [29][30][31] In addition to the study of carbene ligands there have been several developments and patent applications for the telomerization of dienes with methanol catalyzed by classical phosphine ligands, [32,33] bidentate (or chelate) ligands, [34][35][36][37] macrocyclic components, [38] or by cyclopalladated complexes [39] and allylic compounds [40] (Table 3). With macrocyclic compounds, catalyst recovery has been investigated by removing the lower boiling products from the macrocyclic catalyst by distillation.…”

“…The first studies of the telomerization reaction of 1,3butadiene with carbon dioxide were carried out by the research groups of Inoue [118] and Musco. [119] They succeeded in synthesizing lactones (32-34), 1,3,7-octatriene (35), carboxylic acids (36,37), and esters (38,39) in small quantities. In the following years Braunstein et al [120,121] and Behr et al [9,122,123] examined the telomerization leading to the d-lactone (2ethyliden-6-hepten-5-olide, 32) in detail (Scheme 8).…”

Mechanistic Insights into Acetophenone Transfer Hydrogenation Catalyzed by Half‐Sandwich Ruthenium(II) Complexes Containing 2‐(Diphenylphosphanyl)aniline – A Combined Experimental and Theoretical Study

“…A well known P,N ligand is 2‐(diphenylphosphanyl)aniline (hereafter referred as PNH 2 ), whose coordination capability towards several transition‐metal ions is known 2. Usually, PNH 2 chelates the metal in a κ 2 P,N way,2b,2c–3 although κ 1 P2e and bridging2a,2e coordination modes are also reported. Deprotonation of the amine functionality occurs in the presence of a base, giving rise to amido phosphane complexes, where the anionic ligand chelates in a κ 2 ‐P,N way 3a,3d.…”

Exploring the coordination chemistry of N-heterocyclic phosphenium/phosphido ligands using nickelocene as a synthon

“…The nickel center has two bound chlorides and adopts a square pyramidal geometry; however, the apical Ni-Cl(1) bond (2.5396(5) Å) is elongated, similar to other reported five coordinate NiCl 2 square pyramidal compounds. [32][33][34][35] While the origin of the second halide on the Ni center has not been firmly established, it likely originates from either adventitious CH 2 Cl 2 in the reaction mixture or the CH 2 Cl 2 used for extraction in the purification procedure. Consistent with this hypothesis, when CH 2 Cl 2 was deliberately added to the reaction mixture, compound 3 was generated cleanly.…”