Self-Assembly of Silver(I) and Ditopic Heteroscorpionate Ligands. Spontaneous Chiral Resolution in Helices and Sequence Isomerism in Coordination Polymers
作者:Gema Durá、M. Carmen Carrión、Félix A. Jalón、Ana M. Rodríguez、Blanca R. Manzano
DOI:10.1021/cg400636a
日期:2013.8.7
The self-assembly of the ligands bis(pyrazol-1-yl) (pyridine-4-yl)methane (L-1) and bis(3,S-dimethylpyrazol-1-yl) (pyridine-4-yl)methane (L-2) with AgBF4 leads to three types of species: L-1 gives rise to the formation of a boxlike cyclic dimer (1) while L-2 leads to two different coordination polymers that are sequence isomers. With dependence on the crystallization conditions, either a homochiral helix (2) with spontaneous resolution or a zigzag polymer is formed (3). By means of solid-state circular dichroism studies, the presence of both enantiomers in 2 is observed, enriched locally in colonies of crystals. The homochiral motif is stable, even upon removal of guest solvent molecules. The noncovalent interactions in the crystalline structure are clearly affected by the presence of the methyl groups on the pyrazolyl rings. The behavior of the compounds in solution is discussed.
Polynuclear Complexes Containing Ditopic Bispyrazolylmethane Ligands. Influence of Metal Geometry and Supramolecular Interactions
作者:M. Carmen Carrión、Gema Durá、Félix A. Jalón、Blanca R. Manzano、Ana M. Rodríguez
DOI:10.1021/cg201677s
日期:2012.4.4
also isolated. On using other M(II) centers (M = Co, Ni, Zn), which could adopt an octahedral geometry, box-like cyclic dimers formed by the self-assembly of two metal centers and two ligands in a head-to-tail disposition were obtained. All metal ions exhibited a distorted octahedral geometry. A complex of Ag(I) with similar cyclic dimers connected through difluorophosphate anions to generate zigzag chains
Metal Supramolecular Frameworks with Silver and Ditopic Bis(pyrazolyl)methane Ligands: Effect of the Anions and Ligand Substitution
作者:Gema Durá、M. Carmen Carrión、Félix A. Jalón、Ana M. Rodríguez、Blanca R. Manzano
DOI:10.1021/cg5004484
日期:2014.7.2
salts and the potentially ditopicligands bis(pyrazol-1-yl)(pyridine-4-yl)methane (L1) and bis(3,5-dimethylpyrazol-1-yl)(pyridine-4-yl)methane (L2) was undertaken and species’ with discrete or polymeric structures were obtained. Reactions with L1 always yielded derivatives that had a box-like cyclic dimer structure with two metal centers and two ligands. However, on using ligand L2, the resulting structure
不同银盐和潜在的双位配体双(吡唑-1-基)(吡啶-4-基)甲烷(L 1)和双(3,5-二甲基吡唑-1-基)(进行吡啶-4-基)甲烷(L 2)反应,得到具有离散或聚合结构的物质。与L 1的反应总是产生具有盒状环状二聚体结构且具有两个金属中心和两个配体的衍生物。然而,在使用配体L 2时,所得结构强烈取决于阴离子的配位能力。使用具有配位能力的阴离子(X = NO 3 –,CF 3 SO 3 –,PF 2 O 2–),形成了类似的盒状结构。但是,使用配位能力较低的阴离子(X = PF 6 –,ClO 4 –)导致配位聚合物呈螺旋状排列。在两种化合物中观察到自发的拆分,并且在所研究的晶体中仅存在一种对映异构体。将固态圆二色性光谱应用于一束晶体,结果表明可能发生从单个成核点开始的同手性晶体的单个菌落的生长。当螺旋络合物重结晶时,获得盒状环状二聚体。吡唑基环上甲基的存在或不存在对超分子结构有很大的影响。在溶液中,含有L