Copper(I) Halide Complexes with 1,3-Propanebis(diphenylphosphine) and Heterocyclic Thione Ligands:  Crystal and Electronic Structures (DFT) of [CuCl(pymtH)(dppp)], [CuBr(pymtH)(dppp)], and [Cu(μ-I)(dppp)]₂

Abstract

Reaction of copper(I) chloride or bromide with equimolar amounts of the diphos ligand 1,3-propanebis(diphenylphosphine) and a heterocyclic thione (L) in acetonitrile/methanol solvent afforded mononuclear complexes of the type [CuX(dppp)(L)] with the diphosphine ligand acting as a chelating ligand. In contrast, copper(I) iodide under the same conditions gave the dimeric complex [Cu(mu-I)(dppp)](2), which contains doubly bridging iodo ligands. The structures of three complexes, namely, [CuCl(pymtH)(dppp)], [CuCl(pymtH)(dppp)], and [Cu(mu-I)(dppp)](2), have been established by single-crystal X-ray diffraction. Density functional calculations at the B3LYP level of theory provided a satisfactory description of the structural, bonding, electronic, and related properties of the [CuX(PH(3))(2)] and [CuX(1,3-pdp)] (1,3-pdp = 1,3-propane-di-phosphine) complexes and their dimers along with their associations with the pyrimidine-2-thione (pymtH) ligand. The interaction of the pymtH ligand with the Cu(I) metal center in these complexes corresponds to loose associations, the computed interaction energies predicted to be about 20 kcal/mol for all complexes in the series. The bonding mechanism of the thione ligand with the Cu(I) metal centers involves both a sigma-dative and pi-back-bonding components. The coordination of the pymtH ligand is further stabilized by X...H-N bond formation being more pronounced in the chloro than in the iodo derivatives. The Cu-X bond was also found to be a composite bond involving sigma- and pi-dative bonding components. Most important is the presence of pi-type MOs delocalized over the entire four-membered Cu(mu-X)(2)Cu ring, which supports a ring current and could probably account for the nearly equivalent Cu-X bonds in the rhombus. Moreover, all [Cu(mu-X)(PH(3))(2)](2) dimers exhibit a sigma-type MO corresponding to weak Cu.Cu interactions supporting through-ring intermetallic interactions, which seems to be responsible for the stabilization of the otherwise unstable antiaromatic Cu(mu-X)(2)Cu ring.

Synthesis, Spectroscopy, and Structures of Mono‐ and Dinuclear Copper(I) Halide Complexes with 1,3‐Imidazolidine‐2‐thiones

“…121-126°. [29][30][31][32][33][34][35][36][37][38] Complex [(CuBr(κ 1 -S-l-NMe)(PPh 3 ) 2 .CuBr(PPh 3 ) 2 ] (2) has two different four and three coordinated independent molecules in the unit cell. The latter moiety CuBr(PPh 3 ) 2 [47] The bond parameters of complexes under study are similar to those reported for LЈ-NH ligand [47] and other heterocyclic-2-thiones.…”

“…The latter moiety CuBr(PPh 3 ) 2 [47] The bond parameters of complexes under study are similar to those reported for LЈ-NH ligand [47] and other heterocyclic-2-thiones. [29][30][31][32][33][34][35][36][37][38] …”

“…Several heterocyclic-2-thiones such as pyridine-2-thione, pyrimidine-2-thione, thiazolidine-2-thione etc. have formed mixed-ligand complexes such as, [CuX(HL)(PPh 3 ) 2 ], with PPh 3 as co-ligand, [29][30][31][32][33][34][35][36][37][38] whereas no similar mixed-ligand complexes with imidazolidine-2-thiones are known.…”

Luminescent monomeric and polymeric cuprous halide complexes with 1,2-bis(3,5-dimethylpyrazol-1-ylmethyl)-benzene as ligand

“…In particular, formation of halide bridges has been found to be favored for the "soft" iodide but not for the "harder" chloride ligands, whereas both bridging and terminal bonding modes were observed for the bromide ligands since bromide lies on the borderline between soft and hard bases [10]. The luminescent properties of copper(I) halide aggregates have been extensively studied by Ford et al, who showed that luminescent behaviour and geometries of the aggregate are strictly related [11].…”

Synthesis, Characterisation and Luminescent Properties of Mixed‐Ligand Copper(I) Complexes Incorporating N‐Thiophosphorylated Thioureas and Phosphane Ligands

“…A number of heteroligand Cu I complexes containing both aryl-substituted pnictides and cyclic thioureas or pyridinethiolates have also been described. [21][22][23] A combination of these two types of ligands might lead to interesting and unusual photophysical and electrochemical properties. [24] In this contribution we describe new heteroligand complexes of Cu I …”