Supramolecular Heteropentamers As Building Blocks for Metal Organic Materials: Synthesis and Characterization of 1D and 2D 2-Fold Interpenetrated Frameworks

Reactions between (Me4N)(4)[Nb6Cl12(CN)(6)], [Mn(ACEN)Cl] (ACEN(2-) = bis(acetylacetonato)ethylenediamine), and dpyo (dpyo = 4,4'-dipyridyl-N,N'-dioxide) in different ratios led to the crystallization of two cluster-based metal-organic materials (CMOMs): {[Mn(ACEN)(2)[Mn(ACEN)(MeOH)](2)(Nb6Cl12(CN)(6))(dpyo)}center dot 2MeCN (1) and {[Mn(ACEN)(4)(Nb6Cl12(CN)(6))(dpyo)(2)}center dot MeCN center dot 2MeOH center dot 3.5H(2)O (2). Their crystal structures were determined by single-crystal X-ray diffraction. Both materials are built of neutral heteropentamers {[Mn(ACEN)](4)[Nb6Cl12(CN)(6)]} in which the edge-bridged hexacyano octahedral metal cluster [Nb6Cl12(CN)(6)](4-) is functionatized by four [Mn(III)(ACEN)](+) complexes. The supramolecular assemblies are connected to each other by the ditopic ligand, dpyo. In 1, each heteropentamer is trans-bridged by two dpyo linkers to give a neutral chain. Hydrogen bonds between nonbridging cyanides and coordinated methanol ligands further connect the chains into layers which are separated by solvent molecules. In 2 each heteropentamer is trans-bridged by four dpyo linkers while each dpyo is cis-bridged by two heteropentamers to give a 4,4'-net with edge length of 25 A. The 4,4'-nets are further interwoven into a 2-fold (2D -> 2D) parallel interpenetrating layered structure. Magnetic properties and thermal stability of 1 and 2 are presented.