A Manganese(II) Allyl Complex: Synthesis, Structure, and Magnetic Properties of [Li(thf)₄][Mn{η³‐(Me₃Si)₂C₃H₃}{η¹‐(Me₃Si)₂C₃H₃}₂]

Abstract

Lucky thirteen: The first example of a manganese(II) allyl complex, [Li(thf)4][Mn{η3‐(Me3Si)2C3H3}{η1‐(Me3Si)2C3H3}2], contains a tris(allyl)manganate monoanion (depicted). The structure of the anion was determined and shown to contain both π‐ and σ‐allyl ligands, resulting in an unusually low valence‐electron count of thirteen.

Manganese(ii): the black sheep of the organometallic family

“…3). 34 Despite transition-metal allyl complexes having been known for over 40 years, it was not until 2004 that this ligand was applied successfully in the chemistry of manganese(II). Geometry optimizations of the anion 31 and its 'parent' anion [Mn{Z x -(C 3 H 5 ) 3 }] À (32) (where x denotes mixed hapticity of the ligands) in the S = 5/2 spin state of manganese(II) revealed that the steric influence of the silyl substituents on ligand hapticity is minimal and that the 2Z 1 Z 3 arrangement is the preferred arrangement of ligands in both 31 and 32.…”

The Missing Link: Manganese Complexes with Sterically Demanding Pyrrolyl Ligands

“…In contrast, the Mn–C bonds to the adjacent C atoms (C1, C4, C15, and C18) are significantly longer with 2.399(3), 2.344(4), 2.306(4), and 2.369(4) Å, respectively. It is worth comparing these Mn–C distances to those found in the η 3 ‐allyl moiety of [Li(thf) 4 ][(η 3 ‐1, 3‐(Me 3 Si) 2 C 3 H 3 )Mn(η 1 ‐1, 3‐(Me 3 Si) 2 C 3 H 3 ) 2 ] (Mn–C1 2.470(4), Mn–C2 2.348(3) and Mn–C3 2.398 Å) 18. The longer Mn–C2 distance is readily explained by the fact that this position bears only a minor negative charge in the allyl system.…”

Complexes with Sterically Bulky Allyl Ligands: Insights into Structure and Bonding

“…[64] The anion contains both an η 3 -bonded and two η 1 -bonded allyl ligands ( Figure 17). The two σ-bonded allyl groups display nearly identical Mn-C lengths averaging, 2.186(6) Å, whereas the distance to the π-bonded allyl is considerably longer, at 2.348(3)-2.470(4) Å.…”