Synthesis and X‐ray Characterization of Mono‐ and Polynuclear Thiolatocopper(I) Complexes: The Effect of Steric Bulk on Coordination Number and Nuclearity

Abstract

We have synthesized a number of Cu I complexes of thiophenolato ligands with different alkyl substituents in the ortho positions in a single-step procedure starting from a readily available copper(I) precursor to evaluate the coordination preferences of the metal atom. In most cases similar reaction conditions led to the formation of two complexes: a mononuclear complex and a polynuclear cluster, as evident from Xray crystallography. One dinuclear complex formed has the unique geometry of an L 2 Cu 2 (µ-L) 2 core that has not previously been observed for related systems. The steric bulk around the metal atom has a clear effect on the coordination sphere of the complex obtained. Ligands with no ortho sub-

Preparation and X-ray characterization of two-coordinate Cu(I) complex of aliphatic thiolato ligand: Effect of steric bulk on coordination features

“…The structure features a Cu 4 S 6 core which may be regarded as a tetrahedron of Cu atoms inscribed within an octahedron of thiolato ligands [15][16][17][18][19][20][21][22][23][24][25]. In this cluster, each thiolato ligand bridges the edges of the copper tetrahedron, and each copper center is tri-coordinated with a highly planar geometry pronounced by 359.7-359.8°as the sum of angles around the copper center, with total of two NEt þ 4 counter ions.…”

“…Whereas several thiolato-bridged Cu(I) clusters are known, particularly of the Cu 4 S 6 [15][16][17][18][19][20][21][22][23][24][25] and Cu 5 S 6 [25][26][27][28][29] cores, the later exhibiting both three-coordinate and two-coordinate Cu(I) centers, only three examples are known in the literature of two-coordinate mononuclear thiolato Cu(I) complexes [25,29,30], two of which include an aromatic thiophenolato ligands. We have recently reported the effect of the ligand steric bulk on the coordination features of both mononuclear and polynuclear Cu(I) complexes of aromatic thiophenolato ligands [25]. Herein, we present the preparation and X-ray crystallographic characterization of two Cu(I) complexes of aliphatic thiolato ligands, as well as the second example of a two coordinate mononuclear coordination site with an aliphatic ligand that is structurally characterized.…”

Can DFT methods correctly and efficiently predict the coordination number of copper(I) complexes? A case study

“…50 Ligands without ortho substituents, and those with a single ortho substituent, all led to the formation of tri-coordinated complexes (Figs. 1a-1c) while a ligand with two orthosubstituents (one in each position) led to a di-coordinated copper complex (Fig.…”

“…1d). 50 It was concluded that steric bulk around the metal atom strongly affects the coordination sphere of the complex obtained. In fact an earlier study by Koch et al (Fig.…”

“…A thermodynamic cycle describing the various contributions to the reaction energy of the formation of a tri-coordinated Cu(I) complex from a di-coordinated complex and an additional ligand. The number in parentheses represents the experimentally observed 50,51 coordination number.…”