Supramolecular assemblies built of [Nb6Cl12(CN)6]4- octahedral metal clusters and [Mn(acacen)]+ complexes

Reactions between solutions of [Me4N](4)[Nb6Cl12(CN)(6)] center dot 2MeOH and [Mn(L)] Cl (L = acacen(2-) = bis(acetylacetonato) ethylenediamine at room temperature led to the formation of four compounds containing supramolecular assemblies formed of [Nb6Cl12(CN)(6)](4-) and [Mn( L)](+) as building units. The four compounds were characterized by single-crystal X-ray diffraction, IR, elemental analysis, thermogravimetric analysis, and magnetic susceptibility measurements ( for 3). In 1, each cluster is coordinated by one [Mn(L)(MeOH)](+) via a CN- ligand to give an anionic dimeric unit {[Mn(L)(MeOH)][Nb6Cl12(CN)(6)]}(3-), which connect to each other via hydrogen bonding between the CN- ligand and MeOH from the cations [Mn(L)(MeOH)(2)](+) to give anionic tubular-like chains. The structure of 2 comprises trimeric units {[Mn(L)(H2O)](2)[Nb6Cl12(CN)(6)]}(2-) in which each cluster is trans-coordinated by two [Mn(L)(H2O)](+) cations via the CN- ligand. The trimeric units are connected to each other via hydrogen bonding between CN- and the water of coordination to give anionic chains along the crystallographic a axis. The chains are connected to each other through further hydrogen bonding to give an overall three-dimensional hydrogen-bonded framework. In 3, each cluster is coordinated by two [Mn(L)(MeCN)](+) and two [Mn(L)(H2O)](+) via CN- ligand to give neutral pentameric units that are connected through hydrogen bonding between CN- and aqua ligands to give hydrogen-bonded chains along the crystallographic b axis. 4 is based on two supramolecular ions; the cation consists of a heptameric unit {[Mn(L)(H2O)](4)[Mn(L)](2)[Nb6Cl12(CN)(6)]}(2+) in which each cluster is coordinated by six [Mn( L)](+) via CN- ligand, whereas the anion {[Mn(L)](2)[Nb6Cl12(CN)(6)]}(2-) is the same as that found in 2. Electrostatic interactions and hydrogen bonding between these two supramolecular species afford a 1D framework. Magnetic susceptibility shows that 3 is paramagnetic with four high-spin Mn(III) ions. Thermal behaviors of 1-4 are presented.