The structures and photophysical properties of Zn(II) complexes with the tridentate Schiff base ligand HL: 1-((E)-((pyridin-2-yl)methylimino)methyl) naphthalen-2-ol, have been synthesized and fully characterized. The X-ray structures of the complexes showed unusual and inequivalent dimeric assemblies of Zn(II) that were tuned by the counter ions used. The complex [ZnL(HL)] 2(ClO4)2, 1, proves the self-assembly of a box-like structure that stabilized by OH⋯OR contacts within the complex. The complex [Zn2(μ-L)2(NO3)2], 2, contains two symmetrical Zn(II) centers that are directly linked by two oxo bridges from two ligands. The 1H NMR spectra in non-polar solvents such as CDCl3 confirmed the stability of the dimeric assemblies and aggregation in solution. By controlling the counter ions used, e.g. ClO 4 or NO3 and the polarity of solution, the Zn(II) complexes would form molecular aggregates at different extents with different emission properties in the solid and solution states. The solid-state emission spectra exhibited a spectral red-shift on the ligand-based emission besides a growth of a low-energy feature in 1 due to face-to-face π⋯π contacts between the aromatic rings in the box-like assembly. Therefore, complex 1 emits greenish-blue light and complex 2 emits blue light.
|Number of pages||7|
|Journal||Journal of Photochemistry and Photobiology A: Chemistry|
|Publication status||Published - Jul 1 2014|
- Crystal structure
ASJC Scopus subject areas
- Chemical Engineering(all)
- Physics and Astronomy(all)