Tri- and tetracoordinate copper(i) complexes bearing bidentate soft/hard SN and SeN ligands based on 2-aminopyridine

Abstract

The coordination properties of the EN ligands N-(2-pyridinyl)amino-diphenylphosphine sulfide, N-(2-pyridinyl)amino-diisopropylphosphine sulfide, N-(2-pyridinyl)amino-diphenylphosphine selenide, N-(2-pyridinyl)amino-diisopropylphosphine selenide towards copper(I) precursors CuX (X = Br, I), [Cu(IPr)Cl] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), and [Cu(CH(3)CN)(4)]PF(6) were studied. Treatment of CuX with EN ligands resulted in the formation of tricoordinate complexes of the type [Cu(κ(2)(E,N)-EN)X]. The reaction of [Cu(IPr)Cl] with EN ligands, followed by halide abstraction with AgSbF(6), afforded cationic tricoordinate complexes [Cu(κ(2)(S,N)-EN)(IPr)](+), while the reaction of [Cu(CH(3)CN)(4)](+) with two equivalents of EN ligands yielded tetrahedral complexes [Cu(κ(2)(E,N)-EN)(2)](+). Halide removal from [Cu(κ(2)(S,N)-SN)I] with silver salts in the presence of L = CH(3)CN and CNtBu afforded dinuclear complexes of the type [Cu(κ(2)(S,N),μ(S)-SN)(L)](2)(2+) containing bridging SN ligands. With the terminal alkynes HC≡CC(6)H(4)Me and HC≡CC(6)H(4)OMe, complexes of the formula [Cu(κ(2)(S,N)-SN-iPr)(η(2)-HC≡CC(6)H(4)Me)](+) and [Cu(κ(2)(S,N)-SN-iPr)(η(2)-HC≡CC(6)H(4)OMe)](+) were obtained. The mononuclear nature of these compounds was supported by DFT calculations. Most complexes were also characterized by X-ray crystallography.

Can Water Act as a Nucleophile in CO Oxidation Catalysed by Mo/Cu CO‐Dehydrogenase? Answers from Theory

“…At the same time, H 2 O is found to be coordinated to the CO‐bound Cu ion (O(H 2 O)−Cu distance: 2.12 Å) giving rise to a tetracoordinated Cu(I) adduct. Existence of tetra‐coordinated copper(I) complexes has been experimentally confirmed [21,22] . In particular, Olmstead et al .…”

“…Existence of tetra-coordinated copper(I) complexes has been experimentally confirmed. [21,22] In particular, Olmstead However, the involvement of Bt in the nucleophilic attack of water to the C atom of CO is questionable. In fact, it presents a C(CO)À O(H( 2 )O) distance 0.18 Å longer than the corresponding distance of the B intermediate and it is predicted to be 3.9 kcal/ mol less stable than the tricoordinated adduct.…”

N-Heterocyclic Carbene Complexes of Copper, Nickel, and Cobalt

“…A range of 3-coordinate κ N -κ E Cu-IPr complexes with the mixed donor ligands N-E, where N and E are pyridine and S donors of N -(2-pyridinyl)­amino-diorganyl-phosphine sulfides, respectively, have been prepared by the reaction of [CuCl­(IPr)] with the free N-E ligand in the presence of AgSbF 6 as chloride abstractor (Scheme ). In the structure of the complexes, the six-membered chelate rings are puckered, and the NHC plane is nearly perpendicular to the coordination plane …”

Characterization of Cu-ligand bonds in tris-pyrazolylmethane isocyanide copper(I) complexes based upon combined X-ray diffraction and theoretical study

“…Current progress in the synthesis of (RNC)Cu I compounds allows the classification of the reported species to the following types, viz. homoleptic species [Cu(CNR) n ] + (n = 3 and 4) [29,30] and mixed-ligand complexes bearing, apart isocyanide ligand(s), different C- [31][32][33], N- [34][35][36][37], X-(X = halogen) [38] and other donor ligands [39,40]. To the best of our knowledge, no theoretical studies focused on elucidation of ligand properties and activation of RNC species by copper(I) centers are known.…”