A one-dimensional organic–inorganic hybrid constructed by saturated Keggin polyoxoanions and [Cu^I(4,4′-bipy)]_nⁿ⁺ chains

Abstract

A one-dimensional (1-D) organic–inorganic hybrid compound {(H₃O)[Cu^I(4,4′-bipy)]₃[SiW₁₂O₄₀]} · 1.5H₂O (1) has been synthesized from hydrothermal reaction of Keggin polyoxometalate, cupric nitrate and 4,4′-bipyridine (4,4′-bipy). Single crystal X-ray diffraction shows 1-D zigzag chains built up of saturated Keggin polyoxoanions and infinite [Cu^I(4,4′-bipy)] _n ^{n +} units. Zipper-like arrangement of adjacent zigzag chains by hydrogen-bonding interactions leads to a 2-D layer and π–π interactions of 4,4′-bipy ligands from adjacent layers further result in the 3-D structure of 1. All Cu atoms in 1 are three-coordinated with “T-type” geometries, indicating they are univalent in the resultant compound. This result has further been confirmed by the absence of signal in the EPR spectrum of 1.

Keywords:

• Organic–inorganic hybrid
• Hydrothermal synthesis
• Saturated Keggin
• Transition metal complexes

Acknowledgments

This work was supported by the National Science Foundation of China (Grant No. 20571014), the Program for New Century Excellent Talents in University (NCET-07-0169), and the Analysis and Testing Foundation of Northeast Normal University.