Das Hexanitridodimanganat(IV) Li6Ca2[Mn2N6]: Herstellung, Kristallstruktur und chemische Bindung

Abstract

Unverbrückt sind die Mn2‐Einheiten in den isolierten Hexanitridodimangant(IV)‐Ionen der Titelverbindung, der ersten Verbindung mit Mn‐Mn‐Einfachbindungen innerhalb eines komplexen Anions, in der die Manganzentren in der hohen Oxidationsstufe +4 vorliegen. ELF‐Rechnungen zufolge handelt es sich bei der Mn‐Mn‐Bindung um eine Zwei‐Elektronen‐zwei‐Zentren‐Bindung.

Li24[MnN3]3N2 and Li5[(Li1-xMnx)N]3, Two Intermediates in the Decomposition Path of Li7[MnN4] to Li2[(Li1-xMnx)N]: An Experimental and Theoretical Study

“…Hence, the reaction can be described as a stepwise reduction/decomposition from a manganese(V) compound, Li 7 [Mn V N 4 ], over a nitridomanganate(III), Li 24 [Mn III N 3 ] 3 N 2 , to a phase with manganese in an average oxidation state between 1 and 2, Li 5 [(Li 1 - x Mn x )N] 3 ( x ≈ 0.60, oxidation state of Mn +1.6), to finally yield the manganese(I) phase Li 2 [(Li 1 - x Mn I x )N] ( x ≈ 0.67). A ternary intermediate lithium nitridomanganate(IV) corresponding to the recently reported Li 6 Ca 2 [Mn 2 IV N 6 ] was not observed in this study. The precursor Li 7 [Mn V N 4 ] and the first intermediate Li 24 [Mn III N 3 ] 3 N 2 show strong similarities in their crystal structures, yet the former contains tetrahedra [MnN 4 ] 7- , while the latter contains trigonal, slightly nonplanar units [MnN 3 ] 6- (see crystal structures section).…”

Peierls‐Distorted Monoclinic MnB4with a MnMn Bond

“…The ELF value is low but comparable to what has been identified to be a bonding Mn-Mn attraction in Li 6 Ca 2 [Mn 2 N 6 ]. [20] The COHP (Figure 5 B) suggests significant Mn-Mn interactions in the short Mn-Mn contact. Indeed, the Mn-Mn contact in MnB 4 is short enough to be considered a double bond, consistent with expected isolobal analogy rules for d 6 Mn I .…”

The Reduced Nitridogermanates(III) Ca6[Ge2N6] and Sr6[Ge2N6] with Ge−Ge Bonds

“…Each of those compounds features ethane‐analogue [ Tt 2 Ch 6 ] 6− ions. Related compounds in the nitridometalate chemistry of transition metals include the homeotypic hydride Ca 6 [Cr 2 N 6 ]H, [24] as well as Sr 2 Li 6 [Mn 2 N 6 ] and Ca 2 Li 6 [Mn 2 N 6 ], [25, 26] which contain [Mn IV 2 N 6 ] 10− anions in a similar rhombohedral packing motif.…”