Ni‐2,3‐thiophenedithiolate Anions in New Architectures: An In‐Line Mixed‐Valence Ni Dithiolene (Ni₄–S₁₂) Cluster

Abstract

A family of salts that was based on the [Ni(α-tpdt) n-anions (α-tpdt = 2,3-thiophenedithiolate) and the K + crown-ether cations were prepared and were then structurally and magnetically characterised. In [K(18-crown-6)][Ni(α-tpdt) 2 ], the anion has a square planar coordination geometry with ligand disorder and the cations and anions are segregated in alternating layers in the crystal structure, as was found in the previous [Ni(α-tpdt) 2 ] -salts. Two salts were obtained with the [K(15-crown-5) 2 ] + cation. The expected 1:1 salt was obtained, which had the usual anion square planar coordination geometry for [Ni(α-tpdt) 2 ] -but that had a new molecular arrangement based on an anion double chain. In addition, a 2:1 salt

5‐Methylthiophene‐2,3‐dithiolene Transition Metal Complexes

“…The redox properties of the [M(α‐mtpdt) 2 ] complexes were studied by cyclic voltammetry. The redox processes observed are comparable to those previously described for the [M(α‐tpdt) 2 ] complexes with the unsubstituted ligand,6b,7d,12 albeit they are generally at higher oxidation potentials for the unsubstituted ligand. The voltammograms of the Ni and Au complexes are shown in Figure 8, and those of all other complexes are shown in Figure S3.…”

Jaguar: A high‐performance quantum chemistry software program with strengths in life and materials sciences

“…To compute J, it is therefore very important to be able to tune not only the multiplicity on the different metal centers but also the relative orientation of their net spin (i.e., ferromagnetic or antiferromagnetic coupling). Such a fine tuning is possible in the initial guess algorithm employed in Jaguar, and it is therefore often used in such cases …”

A Mixed-Valence Tetra-Nuclear Nickel Dithiolene Complex: Synthesis, Crystal Structure, and the Lability of Its Nickel Sulfur Bonds

“…From the very beginning of dithiolene chemistry, nickel has always been an integral part of many respective investigations, either in the course of the synthesis of dithiolene ligands [21,22] as a dithiolene ligand transmitter to other metal ions (e.g., molybdenum or tungsten) [21,[23][24][25][26][27] or as a central metal of interest for potential applications [7,[28][29][30][31][32][33]. Such applications of dithiolene-bearing compounds include molecular materials with conducting [34], magnetic [35,36], and optical [37] properties on account of their unique electronic structure.…”

“…In cases where two or more nickel ions are bridged by dithiolene sulfur donor atoms, the metal centers might adopt different or partial formal oxidation states. These species can be stabilized by a significant contribution of the extended π-ligands to their frontier orbitals [35]. Respective observations were made with oligo-nuclear nickel complexes, such as [Ni 2 (edt) 3 ] 2− , [Ni 3 (edt) 4 ] 2− (edt = ethane-1,2-di-thiolate) [47], [Ni 2 (dmit) 3 ] (dmit = 2-thione-1,3-dithiole-4,5-dithiolate) [48] (pdt = propane-1,2-dithiol, edt = ethane-1,2-dithiol, dmit = 2-thione-1,3-dithiole-4,5-dithiolate) [49].…”

“…Respective observations were made with oligo-nuclear nickel complexes, such as [Ni 2 (edt) 3 ] 2− , [Ni 3 (edt) 4 ] 2− (edt = ethane-1,2-di-thiolate) [47], [Ni 2 (dmit) 3 ] (dmit = 2-thione-1,3-dithiole-4,5-dithiolate) [48] (pdt = propane-1,2-dithiol, edt = ethane-1,2-dithiol, dmit = 2-thione-1,3-dithiole-4,5-dithiolate) [49]. In 2011, Neves et al [35] reported an interesting mixed-valence tetra-nuclear nickel dithiolene complex [K(18-crown-6)] 2 [Ni 4 (α-tpdt) 4 ] (α-tpdt = 2,3-thiophenedithiolate) with a structure that was unique at that time and constitutes the only known analog of the novel tetrameric complex which is presented here. The originally targeted nickel dithiolene complex in the present investigation was initially merely of interest as a dithiolene ligand transmitter to a molybdenum center in a procedure, which typically works rather well and is commonly applied in our group [21,[23][24][25]50,51].…”