Polyhedral C<sub>2</sub>@Ag<sub>n</sub>cages distorted by ancillary pyridine N-oxide ligands in silver–acetylenediide complexes
作者:Xiao-Li Zhao、Lin-Ping Zhang、Thomas C. W. Mak
DOI:10.1039/b601767c
日期:——
Reactions of the pyridine N-oxide ligands L, L2 and L3 with the silver acetylenediide-containing system under hydrothermal conditions gave rise to four silverâacetylenediide complexes bearing interesting C2@Agn motifs: (Ag2C2)2(AgCF3CO2)8(L1)3.5 (1), (Ag2C2)2(AgCF3CO2)8(L2)2 (2), (Ag2C2)(AgCF3CO2)4(L3) (3) and [(Ag7(C2)(CF3SO3)3(L3)2(H2O)2]·2CF3SO3 (4) (L = nicotinic acid N-oxide, L1 = pyridine N-oxide, L2 = 1,2-bis(4-pyridyl)ethane N,Nâ²-dioxide, L3 = 1,3-bis(4-pyridyl)propane N,Nâ²-dioxide), which exhibit new distorted polyhedral C2@Agn cage motifs. Complex 1 has a pair of acetylenediide dianions encapsulated in a Ag14 aggregate composed of three polyhedral parts, whereas 2 contains an irregular (C2)2@Ag13 double cage. In 3, the basic building unit is a centrosymmetric (C2)2@Ag12 double cage with each component single cage taking the shape of a highly distorted triangulated dodecahedron with one missing vertex. As to complex 4, the core is a C2@Ag7 single cage in the form of a slightly distorted monocapped trigonal prism with four cleaved edges that include all three vertical sides. Furthermore, in the silver-rich environment, the pyO-type ligands are induced to exhibit unprecedented coordination modes, such as the µ5-O,O,O,Oâ²,Oâ² ligation mode of L2 in 2 and the µ4-O,O,Oâ²,Oâ² mode of L3 in 3 and 4.
吡啶 N-氧化物配体 L、L2 和 L3 与含乙炔二化物银的体系在水热条件下反应产生了四种带有有趣的 C2@Agn 基序的银-乙炔化物配合物:(Ag2C2)2(AgCF3CO2)8(L1) 3.5 (1)、(Ag2C2)2(AgCF3CO2)8(L2)2 (2)、(Ag2C2)(AgCF3CO2)4(L3) (3) 和 [(Ag7(C2)(CF3SO3)3(L3)2( H2O)2]·2CF3SO3 (4) (L = 烟酸 N-氧化物,L1 = 吡啶 N-氧化物,L2 = 1,2-双(4-吡啶基)乙烷 N,N-二氧化物,L3 = 1 ,3-双(4-吡啶基)丙烷N,N-二氧化物),其表现出新的扭曲多面体C2@Agn笼图案,具有一对乙炔二价阴离子,封装在由三个多面体部分组成的Ag14聚集体中,而图 2 包含不规则的 (C2)2@Ag13 双笼。在图 3 中,基本结构单元是中心对称的 (C2)2@Ag12 双笼,每个组件单笼呈高度扭曲的三角十二面体形状,缺少一个顶点。对于复合物4,核心是C2@Ag7单笼,其形式为稍微扭曲的单帽三棱柱,具有四个劈开的边缘,包括所有三个垂直侧面。此外,在富银环境中,pyO型配体被诱导表现出前所未有的配位模式,例如2中L2的μ5-O,O,O,O-,O-2连接模式和μ4- 3和4中L3的O,O,O-,O-模式。