Homoleptic Zinc(II) Complexes Based on 4′‐(2‐Thienyl)‐terpyridine: Preparation,Structures, and Properties

The homoleptic complexes Zn^II(4′‐(2‐(5‐R‐thienyl))‐terpyridine)₂(ClO₄)₂ R = hydrogen ( 1 ), bromo ( 2 ), methyl ( 3 ), and methoxy ( 4 )] were prepared. Their structures were determined by single‐crystal X‐ray diffraction analyses, and further characterized by high resolution mass, infrared spectra (IR), and elemental analyses. Single crystal X‐ray diffraction analysis showed that Zn^II ions in the complexes are both six‐coordinate with N₆ coordination sphere, displaying distorted octahedral arrangements. The absorption and emission spectra of the homoleptic Zn^II complexes were investigated and compared to those of the parent complex Zn^II(4′‐(2‐thienyl))‐terpyridine)₂(ClO₄)₂. The UV/Vis absorption spectra showed that the complexes all exhibit strong absorption component in UV region, moreover, complex 4 has an absorption component in the visible region. Thus, the photocatalytic activities of the complexes in degradation of organic dyes were investigated under UV and visible irradiation.