One-Dimensional Coordination Polymers from Hexanuclear Manganese Carboxylate Clusters Featuring a {Mn^II₄Mn^III₂(μ₄-O)₂} Core and Spacer Linkers

Abstract

The bridging of hexanuclear mixed-valent carboxylate coordination clusters of the type [Mn(6)O(2)(O(2)CR)(10)] (R = CMe(3); CHMe(2)) featuring a {Mn(II)(4)Mn(III)(2)(mu(4)-O)(2)} core by geometrically rigid as well as flexible spacer ligands such as pyrazine (pyz), nicotinamide (na), or 1,2-bis(4-pyridyl)ethane (bpe) results exclusively in one-dimensional (1D) coordination polymers. The formation of {[Mn(6)O(2)(O(2)CCMe(3))(10)(Me(3)CCO(2)H)(EtOH)(na)] x EtOH x H(2)O}(n) (1), {[Mn(6)O(2)(O(2)CCHMe(2))(10)(pyz)(3)] x H(2)O}(n) (2), and {[Mn(6)O(2)(O(2)CCHMe(2))(10)(Me(2)CHCO(2)H)(EtOH)(bpe)] x Me(2)CHCO(2)H}(n) (3) illustrates a surprising preference of the interlinked {Mn(6)} units toward 1D coordination chains. In the solid-state, the observed chain propagation axes are either colinear (1 and 3) or perpendicular (2), whereby crystal packing is further influenced by solvent molecules. Magnetic properties of these network compounds can be rationalized based on that the magnetism of discrete [Mn(6)O(2)(O(2)CR)(10)]-type coordination clusters with all-antiferromagnetic intramolecular exchange and weak antiferromagnetic intercluster coupling in 1, 2, and 3 follows the expected exchange coupling strength of the employed spacer linkers.

Versatile Reactivity of MnII Complexes in Reactions with N-Donor Heterocycles: Metamorphosis of Labile Homometallic Pivalates vs. Assembling of Endurable Heterometallic Acetates

“…This complex was stable in air and was not soluble in MeCN, and this reason probable precluding oxidation of Mn II . Pyrazine is a quite typical bridging ligand in the chemistry of manganese, forming polymers with Mn II carboxylates [53,54], as well as with the mixed-valence hexanuclear fragment {Mn II 4Mn III 2(µ4-O)2(O2CR)10} [54][55][56]. From an analysis of literature, as well as from the results of this study it can be noted that the tetranuclear unit {Mn II 2Mn III 2O2(O2CR)6} usually forms in the presence of chelating ligands, such as 2,2′-bipy and phen, while the hexanuclear unit {Mn II 4Mn III 2O2(O2CR)10} is produced in reactions with monodentate N-donor ligands or in the absence of such ligands.…”

‘Metal Complexes as Ligands’ for the Synthesis of Coordination Polymers: A MnIII Monomer as a Building Block for the Preparation of an Unprecedented 1-D {MnIIMnIII}n Linear Chain

“…The vast majority of the previously reported Mn(II/III) polymers includes products that have been resulted from the polymerization of high-nuclearity {Mnx} cluster compounds (x = 3, 6, 12, etc.) [34][35][36][37]. The structurally closest to our reported compound 2 is the 1-D linear chain of [Mn III (4-Me-sal)2(4-Mepy)2Mn II (H2O)2(MeOH)2]+ repeating units [38], which includes the tridentate chelating/bridging ligand 4-methyl salicylic acid (4-Me-salH2) and terminally bound 4-methyl pyridine (4-Me-py), H2O, and MeOH molecules.…”

Manganese, technetium and rhenium

“…59 60 A family of 1D coordination polymers featuring a {Mn II 4 Mn III 2 (m 4 -O) 2 } core have been prepared and characterised. 61 Meanwhile, the mechanism for the formation of substituted manganese(V) cyanidonitrido complexes has been studied using spectrophotometric and stopped-flow techniques. 62 Finally, the largest manganese/oxime cluster with an S = 6 ground state and novel Mn/O core has been reported.…”