Aktivierung von Schwefelhexafluorid an hoch reduzierten niedrig koordinierten Nickel‐Distickstoff‐Komplexen

Abstract

Das Klimagas Schwefelhexafluorid ist in der Literatur ein viel verwendetes Standardbeispiel für ein sehr reaktionsträges anorganisches Molekül, das selbst durch Disauerstoff in einer elektrischen Entladung nicht angegriffen wird. Dennoch sind reduzierte b-Diketiminato-Nickel-Komplexe unter Standardbedingungen in der Lage, SF 6 in Fluorido-und Sulfido-Verbindungen zu überführen. Das Fluorido-Produkt besitzt dabei eine präzedenzlose [NiF] + -Einheit, bei der das Nickelatom nur dreifach koordiniert ist. Der Sulfido-Komplex beinhaltet eine seltene nahezu lineare [Ni(m-S)Ni] 2+ -Anordnung. Die Reaktion wurde mittels 1 H-NMR-, IR-und ESRspektroskopischen Methoden untersucht. Diese führten zur Identifizierung einer Zwischenstufe und gewährten so einen Einblick in den Mechanismus der 8-Elektronen-Reduktion von SF 6 .

Synthesis of a “Masked” Terminal Nickel(II) Sulfide by Reductive Deprotection and its Reaction with Nitrous Oxide

“…Moreover,t heir 1 HNMR spectra are similar to those reported for other Ni II b-diketiminate thiolate complexes,such as [L tBu Ni(SPh)] and [L tBu Ni(SEt)]. [30,31] Subsequent reduction of 1 and 2 with 2equiv of KC 8 in cold (À25 8 8C) Et 2 Oi nt he presence of 2equiv of 18-crown-6 results in the formation of [K(18-crown-6)][L R Ni(S)] (3:R= Me; 4:R= tBu). Complex 3 could be isolated as dark green blocks from hexanes/C 6 H 6 in 66 %y ield, whereas complex 4 was isolated as dark brown plates from toluene/isooctane in 88 %y ield.…”

“…Finally,the NiÀNdistances in 3-5 are comparable to those found in other three-coordinate Ni II b-diketiminate complexes. [29][30][31]34] TheN i ÀSb ond lengths in complexes 3, 4,a nd 5 are amongst the shortest known, and are intermediate between the additive covalent radii projected for nickel-sulfur single (2.13 ) and double bonds (1.95 ). [23,24,35] Forc omparison, [{L tBu Ni} 2 (m-S)], [30] [{(IPr)Ni} 2 (m-S) 2 ]( IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), [36] and [{PhB-(CH 2 StBu) 3 }Ni] 2 (m-S) [32] display comparable NiÀSb ond lengths of 2.0651(7), 2.0972(6), and 2.0714(4) , respectively, despite each possessing ab ridging S 2À ligand.…”

Stabilization of β‐Diketiminato Nickel(I) with Alkaline Metal Halide Entities for Small Molecule Activation

“…β‐Diketiminato nickel(I) complexes have demonstrated unique potential in the area of small molecule activation . They have been shown to react, for instance, with the group 16 elements, dinitrogen, phosphorus, but also with SF 6 , CO 2 , and dihydrogen,, weakening bonds through transfer of electron density or even cleaving them reductively. However, the co‐ligand saturating the residual coordination sphere of the central nickel(I) atoms is also decisive.…”

The Decomposition Products of Sulfur Hexafluoride (SF6) with Metals Dissolved in Liquid Ammonia

“…They described the reaction between sulfur hexafluoride and hydrogen sulfide to sulfur and hydrogen fluoride. Furthermore, reactions with elemental sodium at 200 • C and several catalytic activations with nickel-or rhodium-complexes of SF 6 have been published [4,5,8].…”

“…Because of its excellent electric characteristics and high chemical stability, it is used as a dielectric medium in high-voltage circuit breakers, transformers, capacitors and many more industrial applications [3]. Since the search for a replacement material that is less harmful to the environment or that is easier to dispose of has not yet been successful, the decomposition of sulfur hexafluoride remains a current field of research [4][5][6].…”