Syntheses, Structures, and Luminescent Properties of two Cadmium(II) Entangled Frameworks Based on 5‐Bromoisophthalic Acid and Bipyridyl Ligands

Two cadmium(II) entangled frameworks, Cd(BIPA)(bpe)1.5 (1) and Cd(BIPA)(bpp)(H2O) (2), were prepared by hydrothermal reactions based on rigid 5-bromoisophthalic acid (H2BIPA) and two flexible bipyridyl ligands 1, 2-bis(4-pyridyl)ethane (bpe) and 1, 3-bis(4-pyridyl)propane (bpp). The complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Complex 1 is a rare example of a polycatenated array of 1D nanotubes, whereas complex 2 exhibits a three-dimensional twofold interpenetrating diamondoid network. The analysis results reveal that the flexibility of the bipyridyl ligands plays a significant role in the structure of the final products. Moreover, the luminescent properties of the complexes were investigated.