A Computational Study of Metallacycles Formed by Pyrazolate Ligands and the Coinage Metals M = Cu(I), Ag(I) and Au(I): (pzM)n for n = 2, 3, 4, 5 and 6. Comparison with Structures Reported in the Cambridge Crystallographic Data Center (CCDC)

Abstract

The structures reported in the Cambridge Structural Database (CSD) for neutral metallacycles formed by coinage metals in their valence (I) (cations) and pyrazolate anions were examined. Depending on the metal, dimers and trimers are the most common but some larger rings have also been reported, although some of the larger structures are not devoid of ambiguity. M06-2x calculations were carried out on simplified structures (without C-substituents on the pyrazolate rings) in order to facilitate a comparison with the reported X-ray structures (geometries and energies). The problems of stability of the different ring sizes were also analyzed.

The Influence of Aryl Substituents on the Supramolecular Structures and Photoluminescence of Cyclic Trinuclear Pyrazolato Copper(I) Complexes

“…Many cyclic trinuclear pyrazolato Copper(I) complexes, with the notable exception of [Cu(μ-L5pz)]3, have intermolecular cuprophilic interactions between each trinuclear plane and Cu•••Cu distances ranging in length from 2.9099(4) to 4.3155 Å [28][29][30]. Similar metallophilic interactions have been observed in other trinuclear complexes of group 11 metal (I) ions [1][2][3][4][5][6][7][8][9].…”

“…Cyclic trinuclear complexes with group 11 metal(I) ions have been of interest to coordination chemists for three decades [1][2][3][4]. One of the ligands known to form these cyclic trinuclear complexes is pyrazolate, which is a bridging ligand that coordinates many transition metal ions in a Npz-M-Npz linear mode (Npz = pyrazolyl nitrogen atom) [5][6][7][8][9][10].…”

“…The first structural characterization of the cyclic trinuclear pyrazolato group 11 metal(I) complexes was performed by Fackler and co-workers in 1988 for [Cu(µ-(3,5-Ph 2 pz)] 3 •1/3(n-hexane) (3,5-Ph 2 pz − = 3,5-diphenyl-1-pyrazolate anion, denoted here as [Cu(µ-L5pz)] 3 •1/3(n-hexane)) [11], quickly followed by a report of the corresponding silver(I) and gold(I) analogues: [Ag(µ-(3,5-Ph 2 pz)] 3 and [Au(µ-(3,5-Ph 2 pz)] 3 [12]. Since this pioneering research, many cyclic trinuclear pyrazolato group 11 metal(I) complexes have been prepared [1][2][3][4][5][6][7][8][9][10]. In the present work, we investigated new copper(I) complexes, because of the abundance of this metal [13].…”

Synthesis and Structural Characterization of a Silver(I) Pyrazolato Coordination Polymer

“…Cyclic trinuclear complexes with monovalent coinage metal ions have been of interest to coordination chemists for three decades [ 1 , 2 , 3 ]. One of the ligands known to form these cyclic trinuclear complexes is pyrazolate [ 4 , 5 , 6 ], which is known to act as an A-frame-like bridging ligand with some metal ions, with an Npz–M–Npz linear coordination mode (pz = pyrazolate anion, C 3 H 3 N 2 − ) [ 1 , 2 , 3 , 4 , 6 , 7 , 8 , 9 ]. Early studies in 1970 suggested that silver(I) pyrazolato complexes existed as a polymeric 1-D chain [Ag(pz)] n ( Figure 1 , left) [ 10 ].…”

Special Issue “Recent Advances in the Synthesis, Functionalization and Applications of Pyrazole-Type Compounds”

“…Elguero and Alkorta reported a computational study of metallacycles formed by pyrazolate ligands and the coinage metals (pzM) n for n = 2, 3, 4, 5 and 6 and carried out a comparison with structures reported in the Cambridge Crystallographic Data Center (CCDC). They discussed the most common size of the metallacycles’ ring depending on the metal and analyzed the stability of different ring sizes [ 1 ]. By using an unexpected synthetic method, Leznoff and Fusijawa et al obtained and characterized a silver(I) pyrazolate complex [Ag(µ-L1Clpz)] n as a coordination polymer, thus broadening the family of silver(I) coordination polymers [ 2 ].…”