A self-assembled octanuclear complex bearing the uncommon close-packed {Fe₄Mn₄(μ₄-O)₄(μ-O)₄} molecular core

Abstract

A one-pot open-air reaction of manganese powder with iron(ii) chloride in DMF solution of the Schiff base (H2L) formed in situ from salicylaldehyde and hydroxylamine hydrochloride yields the heterometallic complex [Fe4(μ4-O)4Mn4(L)8(DMF)4]·2DMF (). Single crystal X-ray analysis shows that its molecular structure is based on the octanuclear core {Fe4Mn4(μ4-O)4(μ-O)4} with a quite rare molecular structure type {M8(μ4-X)4(μ-X)4}, where the central cube-like iron motif is modified with four terminal manganese fragments, the whole core being presented as the {Fe4(μ4-O)4} + 4{Mn(μ-O)} combination. Using the data from the Cambridge Structural Database (CSD), an analysis of the octanuclear structures with similar central {M4(μ4-X)4} fragments was performed. The hierarchical order of molecular structure types with the general formula M8Xn for such compounds was proposed and the topological features as well as the factors that influence the molecular type formation are discussed. Variable-temperature (1.8-300 K) magnetic susceptibility measurements reveal an antiferromagnetic coupling among the magnetic centres in .

Mn(III) Chain Coordination Polymers Assembled by Salicylidene-2-ethanolamine Schiff Base Ligands: Synthesis, Crystal Structures, and HFEPR Study

“…Manganese complexes 1 – 8 were obtained via the “direct synthesis” (DS) approach, which is based on using regular metal powders instead of their salts as a source of metal. This method has been widely investigated by our group, , and it has been shown that in some cases there are advantages in exploiting DS conditions as compared to the traditional “wet” chemistry. For example, a better morphology of the crystal products and absence of contaminating anions were noticed.…”

Synthesis and Interconversion of V4, V7, and V8 Oxide Clusters: Unexpected Formation of Neutral Heptanuclear Oxido(alkoxido)vanadium(V) Clusters [V7O17(OR)(4,4′-tBubpy)3] (R = Et, MeOC2H4)

“…To our knowledge, 1 provides the first example of the homometallic oxide cluster possessing this type of structure . It is also noteworthy that octanuclear complexes having a central {M 4 (μ 4 -X) 4 } cube (M = a metal atom; X = a bridging atom) modified with four additional metal-containing units analogous to 1 are limited in number as mentioned by Kokozay and Pombeiro et al…”

Synthesis and crystal structure of a heterobimetallic nickel–manganese 12-metallacrown-4 methanol disolvate monohydrate compound

“…One area lacking is the use of two different transition-metal ions in an archetypal MC. While several examples of heterobimetallic 3d 'collapsed' metallacrowns, species without a central MC cavity and thus no central metal ion (Psomas et al, 2001;Gole et al, 2010), and inverse metallacrowns, species that bind a non-metal atom in the central MC cavity to the ring metal ions (Szyrwiel et al, 2013;Shiga et al, 2014;Zhang et al, 2014;Nesterova et al, 2015), have been reported, only two heterobimetallic 3d archetypal 12-MC-4 compounds have been described to date. In 2014, Happ and Rentschler reported a Cu II (DMF) 2 Cl 2 [12-MC Fe(III)N(shi) -4](DMF) 4 Á2DMF compound ISSN 2056-9890 that contains Fe III ions in the ring positions and a Cu II ion captured in the central MC cavity (Happ & Rentschler, 2014).…”