Self-Assembly of Cluster-Based Nanoscopic Supramolecules into One-Dimensional Coordination Polymers

Jian-Jun Zhang, Sergio Aarón Gamboa, Barry Julian Davis, Abdessadek Lachgar
2009 Advances in Materials Science and Engineering  
Octahedral metal clusters[Nb6Cl12(CN)6]4−,(Mn(Salen))+(or(Mn(7-MeSalen))+) (Salen=N,N′-ethylene-bis-(salicylidene)iminate) and ditopic organic linkers (4,4′-bpe(trans-1, 2-bis(4-pyridyl)-ethylene) or4,4′-dpyo(4,4′-dipyridylN,N′-dioxide)) self-assemble to form three cluster-based 1D coordination polymers:[Mn(Salen)(MeOH)2]2{(4,4′-dpyo)[(Mn(Salen))2(Nb6Cl12(CN)6)]}·2MeOH(1),{(4,4′-bpe)[(Mn(7-MeSalen))2(Mn(7-MeSalen)(H2O))2(Nb6Cl12(CN)6)]}·1.5MeCN·8H2O(2),
more » ... n)(H2O))2]{(4,4′-bpe)2[(Mn(Salen)(MeOH))2(Mn(Salen))2(Nb6Cl12(CN)6)][(Mn(Salen))2(Nb6Cl12(CN)6)]}·16H2O(3). Single crystal X-ray diffraction analyses show that the frameworks of the three coordination polymers are built of heterotrimeric and/or heteropentameric supramolecular species linked by ditopic organic ligands. The framework of1consists of anionic chains built of heterotrimeric dianions[(Mn(Salen))2(Nb6Cl12(CN)6)]2−(T) linked by4,4′-dpyo. The chains run along two directions ([0 2 −2] and [0 3 3]) leading to the formation of channels along the crystallographic (a) direction where the cations [Mn(Salen)(S)2]+and solvent molecules are located. Also,2was reported earlier, it possesses a neutral 1D chain built of neutral heterpentameric supramolecules:[(Mn(7‐MeSalen))2(Mn(7‐MeSalen)(S))2(Nb6Cl12(CN)6)](P) linked by4,4′-bpeligands. Hydrogen bonds between non-bridging cyanide ligands and coordinated solvent molecules connect the chains into 2D hydrogen-bonded frameworks. Finally,3features an anionic chain, built of alternating heterotrimers[(Mn(Salen))2(Nb6Cl12(CN)6)]2−and heteropentamers[(Mn(Salen)(S))2(Mn(Salen))2(Nb6Cl12(CN)6)]linked by the organic spacer4,4′-bpe. The anionic charge is compensated by the in situe-assembled[Mn(Salen)(S)(4,4′‐bpe)Mn(Salen)(S)]2+dimers. Magnetic measurements reveal that the Mn(III) ions are well isolated and only weak magnetic interactions are observed. The thermal stability of the three compounds was investigated.
doi:10.1155/2009/579123 fatcat:px4ovrnyujembmlklkgbcr7rgq