Supramolecular Assemblies Built of [Nb6Cl12(CN)6]4- Octahedral Metal Clusters and [Mn(acacen)]+ Complexes

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• 作者：Huajun Zhou ; Abdessadek Lachgar
• 刊名：Crystal Growth & Design
• 出版年：2006
• 出版时间：October 2006
• 年：2006
• 卷：6
• 期：10
• 页码：2384 - 2391
• 全文大小：1143K
• 年卷期：v.6,no.10(October 2006)
• ISSN：1528-7505

文摘

Reactions between solutions of [Me₄N]₄[Nb₆Cl₁₂(CN)₆]·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 coordinatedby one [Mn(L)(MeOH)]⁺ via a CN^- ligand to give an anionic dimeric unit {[Mn(L)(MeOH)][Nb₆Cl₁₂(CN)₆]}^3-, which connect toeach 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-coordinatedby two [Mn(L)(H₂O)]⁺ cations via the CN^- ligand. The trimeric units are connected to each other via hydrogen bonding betweenCN^- and the water of coordination to give anionic chains along the crystallographic a axis. The chains are connected to each otherthrough further hydrogen bonding to give an overall three-dimensional hydrogen-bonded framework. In 3, each cluster is coordinatedby two [Mn(L)(MeCN)]⁺ and two [Mn(L)(H₂O)]⁺ via CN^- ligand to give neutral pentameric units that are connected throughhydrogen bonding between CN^- and aqua ligands to give hydrogen-bonded chains along the crystallographic b axis. 4 is based ontwo supramolecular ions; the cation consists of a heptameric unit {[Mn(L)(H₂O)]₄[Mn(L)]₂[Nb₆Cl₁₂(CN)₆]}²⁺ in which each clusteris 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. Magneticsusceptibility shows that 3 is paramagnetic with four high-spin Mn(III) ions. Thermal behaviors of 1-4 are presented.