Combining two-directional synthesis and tandem reactions. Part 4: A concise approach to the spirocyclic core of halichlorine and the pinnaic acids

A synthesis of the spirocyclic core structure of halichlorine, an inhibitor of the induced expression of VCAM-1 and the pinnaic acids, inhibitors of PLA₂, is presented. A two-directional strategy is employed, in conjunction with a tandem oxime formation/Michael addition/cycloaddition to form the key azaspirocyclic skeleton in a very direct manner.     

Syntheses,crystal structures and magnetic properties of two honeycomb-layered bimetallic assemblies,K2[NiII(cyclam)]3[FeII(CN)6]2 · 12H2O and [NiII(cyclam)]3[FeIII(CN)6]2 · 16H2O

Two bimetallic assemblies, K₂[Ni^II(cyclam)]₃[Fe^II(CN)₆]₂ · 12H₂O (1) and [Ni^II(cyclam)]₃[Fe^III(CN)₆]₂ · 16H₂O (2) (cyclam = 1,4,8,11-tetraazacyclotetradecane), were obtained by reaction of K₄[Fe(CN)₆] and [Ni(cyclam)](ClO₄)₂ in aqueous media at different temperatures. Their crystals were structurally determined and magnetic properties were studied. Both of the compounds have honeycomb-layered structures, which are formed by Fe₆Ni₆ units linked through the cyanide bridges. Structure (1) consists of polyanions containing Ni^II–NC–Fe^II linkages and K⁺ cations, while structure (2) is a two-dimensional neutral layer containing Ni^II–NC–Fe^III linkages. The magnetic properties of (1) and (2) have been investigated in the 5–300 K range. Compound (1) exhibits a weak antiferromagnetic interaction with Weiss constant = –0.35 K; compound (2) shows ferromagnetic intralayer and antiferromagnetic interlayer interactions.     

配位聚合物[HgI2(bpea)]n[bpea=1,2-双(4-吡啶基)乙烷]的合成结构表征和光学折射效应

制备4,4-连吡啶基二卤加和物[MX2(4,4′-bipy)]n仍然有较大困难.这类化合物数量不多且已报道的多为难处理的微晶材料.本文在室温下通过简单的操作合成了新的碘化汞连吡啶乙烷加和物[HgI2(bpea)]nox-射线单晶衍射分析表明其中的汞原子通过与两个碘原子以及吡啶乙烷的两个氮原子配位形成扭曲的四面体构型.每个HgI2单元由bpea桥连形成锯齿状链.其非线性光学性质用8-纳秒激光在532nm波长进行了研究.该化合物相对于入射光表现为一定的光学吸收和强的自聚焦效应,其三阶非线性吸收系数α2=1.1×10-11m@W-1,折射系数n2=5.29×10-188m2@w-1.     

一个生物相关单一手性二维金属有机鲱骨形分子网格:双-3-氨基-(S)-酪氨酸钴(Ⅱ)

The first example of homochiral two-dimensional neutral cobalt(Ⅱ)-3-amino-(S)-tyrosine (ATYR) coordination polymer, bis(3-amino-(S)-tyrosinato)cobalt(Ⅱ) 1 was synthesized under the hydrothermal reaction of Co(ClO₄)₂·6H₂O with ATYR in which 1 displays modest second harmonic generation response.