摘要:
IntroductionSystematic variation of metal-bonded halogen and substituents in the pyridine ligands results in the series of cadmium(ii) complexes represented inScheme 1.We recently reported the syntheses and structures of the first one-dimensional coordination polymers based on halogen-bridged edge sharing zinc(ii) octahedra.1According to our experience with the coordination chemistry of zinc(ii) the existence of this structure type is limited to chlorine as bridging halogen ligand and a narrow selection of pyridine derivatives. In general reactions of zinc dihalides with pyridine or its derivatives yield mononuclear tetrahedral complexes.1–14In contrast to these findings the chain polymers [Cd(μ-X)2py2]∞(X = Cl, Br; py = pyridine) have already been reported in the literature.2,15,16It is tempting to attribute this difference in the coordinationchemistry between zinc(ii) and the higher homologue cadmium(ii) to the size of the cations.We therefore decided to undertake a systematic study of nine Cd(ii) complexes involving substituted pyridine ligands. Single crystal X-ray diffraction on eight of these compounds shows that indeed a much wider range of halogen-bridged coordination polymers exists. Within the resulting series of polymers variation of both bridging and terminal ligands can be used to fine-tune the metal⋯metal distance and hence to adjust the separation between the donor ligands. Details of the intra- and inter-molecular geometry and their possible correlations will be discussed.
ISSN:1466-8033
DOI:10.1039/b110208g
出版商:RSC
年代:2001
数据来源: RSC