Preparative and Electrochemical Investigations on the Electron Sponge Behavior of Cobalt Telluride Clusters: CO Substitution in [Co₁₁Te₇(CO)₁₀]ⁿ⁻ Ions (n=1, 2) by PMe₂Ph and Crystal Structure of [Co₁₁Te₇(CO)₅(PMe₂Ph)₅]

Abstract

ions (m 1 ± 5; n 1, 2). Each of these intermediates is distinguished by at least one oxidation and two reduction waves, giving rise to a total of 21 redox couples and 27 electroactive species. The electron sponge character of the new compounds is particularly pronounced in 5, which exhibits charges n between 1 and À 4 corresponding to metal valence electron counts of between 146 and 151.

Study of Polyoxometalates as Electrode Materials for Lithium‐Ion Batteries: Thermal Stability Paves the Way to Improved Cycle Stability

“…POMs show excellent stability against reduction and oxidation and can absorb and release up to 24 electrons in fast and reversible one‐ or multi‐electron reactions. They are called “electron sponges” [14,15] and considered as ideal candidates for electrode materials. Moreover, POMs are widely used as salt for aqueous electrolyte in their acidic form due to their good solubility of ∼0.8 M in water at 25 °C [16–18] .…”

Metal Telluride Clusters — From Small Molecules to Polyhedral Structures

“…Neutral clusters comprising the intact Co 11 Te 7 cage are accessible by the reaction of phosphanes L with the salts 20 or 22 and subsequent chromatography on silica gel. In a very complex reaction the substituted clusters [Co 11 Te 7 (CO) 10− m L m ] ( m = 3, 4, 5) are formed, regardless of the charge of the initial cluster anion 55. Electrochemical studies of the reaction of 22 with L = PMe 2 Ph reveal that there is a stepwise substitution of CO groups, in which differently substituted cluster anions [Co 11 Te 7 (CO) 10− m (PMe 2 Ph) m ] n − ( m = 1−5, n = 1, 2) may be formed as intermediate products.…”

“…Each of these intermediates exhibits at least three electron‐transfer processes, leading to a total of 21 redox couples with 27 electroactive species. It is noteworthy that each replacement of a CO ligand by PMe 2 Ph in [ 1 ] − causes a shift of about 200 mV towards more negative potentials (Scheme ) 55. As a consequence, reduction becomes more difficult and oxidation easier.…”

“…The molecular structure of [Co 11 Te 7 (CO) 5 (PMe 2 Ph) 5 ] contains the same cluster geometry as the precursor anion [Co 11 Te 7 (CO) 10 ] − 55. The replacement of five π‐acceptor CO ligands by PMe 2 Ph and the oxidation of the cluster core by one electron do not affect significantly the bond parameters in the Co 11 Te 7 core when compared to the parent cluster anions.…”

Selective Synthesis of Co8S15 Cluster in Bowl-Shaped Template of the Pentaaryl[60]fullerene Ligand

“…The Co–Co distances in the central Co 6 structure can be divided into two types: weak Co–Co bonds with lengths around 2.57 Å (Co2–Co3, Co3–Co4, Co4–Co5, Co5–Co6, and Co6–Co7; blue lines in Figure ) and nonbonding Co–Co distances of around 2.94 Å (Co2–Co5 and Co4–Co7; green lines in Figure ) . There have been many reports on Co–Co bonds in multinuclear cobalt complexes, but the present bonding mode is the first example among various bonding modes. Regarding the 15 sulfur atoms, four S–S single bonds were found in the structure of 2 .…”