TY - JOUR
T1 - Structure, aggregation and spectroscopic properties of self-assembled Zn(II) Schiff base complexes
AU - Al Rasbi, Nawal K.
AU - Adams, Harry
AU - Alshabibi, Ibtisam
AU - Alamri, Fatma
N1 - Funding Information:
We would like to thank Mrs. Susan Bradshaw (University of Sheffield, UK) for recording the 1 H NMR spectra of the complexes. We also thank Sultan Qaboos University for financial support.
PY - 2014/7/1
Y1 - 2014/7/1
N2 - 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.
AB - 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.
KW - Aggregation
KW - Crystal structure
KW - Emission
KW - Zinc
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U2 - 10.1016/j.jphotochem.2014.03.020
DO - 10.1016/j.jphotochem.2014.03.020
M3 - Article
AN - SCOPUS:84899819645
SN - 1010-6030
VL - 285
SP - 37
EP - 43
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
ER -