摘要:
IntroductionMolecular architecture constructed from metal-based coordination is an expanding field which leads to the development of new classes of functional materials. These complexes have potential application in the field of magnetic materials,1molecular adsorption,2host–guest chemistry3and catalysis.4However, coordination polymers with open framework structures are of interest from a structural point of view and their mimicry of microporous solids. The various factors which can influence the structural topologies in coordination polymers are the coordination geometry of the metals, structure of the spacer ligand, counter ions and reaction conditions. A building block approach has been utilized for the design of coordination polymers, which are assembled from suitable metal centres and organic ligands of different size and nature. A family of metal bridging building blocks containing 4pyridyl donors having two coordination sites of the rigid ligands are often used to construct coordination polymers.5Because of their ability to form Hbonded networks, the incorporation of the flexible 4pyridyl ligands as linkers opens up more research avenues for coordination polymers to create high-dimensional networks. We chose 1,2bis(4pyridyl)ethane as it exhibits different conformations:anti(extended),syn(folded) (Fig. 1) and also because of its versatile nature as a spacer in any extended system. The dimensions of the polymer motif can be increased by cross linking the low-dimensional polymer by weaker intermolecular interactions such as hydrogen bonding and stacking in the solid state. In an endeavour to understand the network topology of the flexible bridging ligand 1,2bis(4pyridyl)ethane) (bpe) with the Co(II) metal centre by taking advantage of its conformational flexibility and the versatile binding mode, the {[Co(bpe)2(H2O)2](ClO4)2·2H2O}ncomplex was synthesized and structurally characterized.Schematic diagram showing the (a)synand (b)anticonformations of the bpe ligand.
ISSN:1466-8033
DOI:10.1039/b009706n
出版商:RSC
年代:2000
数据来源: RSC